Design Event

[Urvina]

I have read a lot on the design event, but I am still not satisfied. What can our team do to get the most points? How can we impress the judges' pants off? I don't see how we can do something or organize the car's system in a way that other teams haven't already done.

So much has already been done before, its seems like all it is know is how well you can copy other team's cars. I hope that's not the case, so if anyone has any uplifting words, please spill them!

Thanks for the help,

Erin Urvina
University of Alaska Anchorage
FSAE '06 Team Leader

[Urvina]

I have read a lot on the design event, but I am still not satisfied. What can our team do to get the most points? How can we impress the judges' pants off? I don't see how we can do something or organize the car's system in a way that other teams haven't already done.

So much has already been done before, its seems like all it is know is how well you can copy other team's cars. I hope that's not the case, so if anyone has any uplifting words, please spill them!

Thanks for the help,

Erin Urvina
University of Alaska Anchorage
FSAE '06 Team Leader

[Denny Trimble]

Justify every single design decision you make, and back it up with physical testing. Then, present it all in a comprehensive, compelling presentation, with beautiful plots and well-indexed 3" thick design notebooks.

And spend some time polishing the car, too. Judges like shiny things.

[jack]

so strait forward, how could you not get into design semifinals right?? http://fsae.com/groupee_common/emoticons/icon_razz.gif

[Z]

Yes Erin, judges do like shiny things, and they don't like change - so copy last year's winning car but nickel plate every square inch!

Seriously though, if you come up with a great NEW design that wins outright you probably won't have scored many Design points - the judges won't recognise your design as good (next year you might do better). But if you win outright - who cares. Design isn't worth much, you have to win Endurance to do really well.

An inverted aerofoil underbody will work but not very well (you're other thread). Ground effects aero is possibly the best thing you could do, but you have to do it right to get it to work right. It doesn't work at all like normal aeroplane wings (it works much better) so throw away the aero textbooks.

As a first year team you might do best with a very simple car - 600cc go-kart with simplest suspension that complies with rules - and add ground effects. If the GEs don't work just ditch them and you will still have a fast car.

[gug]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Z:
Yes Erin, judges do like shiny things, and they don't like change - so copy last year's winning car but nickel plate every square inch!

Seriously though, if you come up with a great NEW design that wins outright you probably won't have scored many Design points - the judges won't recognise your design as good (next year you might do better). </div></BLOCKQUOTE>

what did you mean by "the judges wont recognise your design as good"? our car was massively different to last year (went from double wishbone to de dion rear suspension, added 2 wings, gear drive rather than chain, pneumatic shifting rather than mechanical link, completly different intake design (same material though), handmade wheels, custom sump, etc. etc.), and it won design.

there was a theory running around some of our team that all our innovation actually helped with the design win, because the judges could see that we had designed this all from scratch (this is nothing official from the judges, so dont take it as a hint on how design judging works). i guess you can find out at this years competion, because Adelaide is only making small improvements to last years design, rather than the massive jump that we made.

[James Waltman]

Gug,
In Detroit it doesn't seem to matter how much stuff a team decides to design and manufacture for themselves. The Design competition is about proving you made the best choice.

I bet that last year we had more parts on our car that we designed and manufactured ourselves than any other team there. I also think we had one of the more innovative (at least different) cars in the competition. We couldn't do the things that Denny mentioned above and we got a poor score in the Design competition.

I heard from two top design judges that there was only one school that could answer all the questions they had. It was Cornell. We were talking to the guys from Cornell last year as we packed up. They were disappointed because the design judges mentioned that their car didn't have much innovation. Guess what score they got.

[gug]

i wasnt actually in the design event, so i shouldnt be commenting too much on what we did and didnt do, cause ill probably get it wrong...

[Z]

Gug, my point is that judges are human. As such, most of them have the following two weaknesses.

1. Most people won't recognise a good idea if it is a truly NEW idea. I've just been reading about the history of flight. Back in the 1890's Frederick Lanchester (a pom who also developed many amazing automobile innovations) proposed the vortex (or circulation) theory of wing lift. This is the current, best, most reasonable, accurate... explanation of how wings work. Fred sent papers to two leading scientific societies but was rejected by both because they weren't interested in "the dreams of madmen".

2. Most people think that to improve something you have to ADD to it - ie. make it more complicated, expensive, "shiny", etc. This is especially so amongst engineers who spend a lot of time designing new stuff, so they like to see lots of complicated new stuff designed by others.

If a team came to FSAE with a car with a single cylinder 600cc engine, clutch and neutral but no gears, very simple tube chassis, beam axles front and rear, go-cart steering instead of R&P, smallest diameter wheels, etc. - ie. a powered up go-cart - and if it was painted brown (hey, that's what the sponsor wanted), well I reckon it might come last in Design. What have the judges got to mark!? I agree that if the team could justify all its decisions, produce detailed performance simulations etc., that they would get some marks, just not many.

Nevertheless, I think this sort of car would be fast enough to win outright. Even faster if it had a rather simple looking (brown?) undertray for ground effects. The "innovation" on this car is that it is missing a whole lot of stuff. It has been KISSed. I don't know how many judges would recognise that.

[Denny Trimble]

Sounds like Z should talk with Rob Woods...

It's not the fault of the judges if they don't notice your innovation. It's your task to sell it to them, to show them the benefits and prove it's not witchcraft.

The best way to prove your idea is a good one is to physically test it. Clean up on the track and the naysayers will change their tune.

Our '99 car was very simple, the "standard" configuration of spaceframe, 4cylinder, 13" wheels, etc. It had good geometry, and poor shocks, but it was done fairly early and well-tested. We got 47th in design and 2nd in endurance that year, 5th overall.

I think you'll find your team's execution is more important than its design expertise if you're looking to finish well overall.

[PatClarke]

Oh Dear!!
There might be some people in this thread who are earning a little asterisk beside their name in the judge's black book! Some of these posts are the greatest load of twaddle I have ever read!

The judges read the Design Review and look at your car....so they know what you have done! They can see it! They have looked at literally hundreds of cars! They know what they are looking at!
Then they talk with the designers. This is where they find out WHY you did whatever you did. A team can build a fantastic car, but if they don't know why..or more to the point, can't convince the judges they know why, then they won't score well! Ask one very high profile US team from recent history who didn't make the semis for this very reason. Or ask Frank from UQ about what happened in the UK last year!

On the other hand, a team with a reasonably simple car who really understand what they have, and why they have it, will score pretty well.
Simplistic statements like "The judges like shiny things" and "Most people won't recognise a good idea if it is a truly NEW idea" only underline to me why some particular teams will never win design because they don't take the judges seriously! Remember, the judges have 'been there and done that' thats why they are judges. You don't have to build a car to impress the judges.
Rather, you design, build and understand your car, and express that understanding to the judges at the comp! That will impress them more than any 'bling bling'!
PDR

[Test Driver]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Z:

If a team came to FSAE with a car with a single cylinder 600cc engine, clutch and neutral but no gears, very simple tube chassis, beam axles front and rear, go-cart steering instead of R&P, smallest diameter wheels, etc. - ie. a powered up go-cart - and if it was painted brown (hey, that's what the sponsor wanted), well I reckon it might come last in Design. What have the judges got to mark!? I agree that if the team could justify all its decisions, produce detailed performance simulations etc., that they would get some marks, just not many.

Nevertheless, I think this sort of car would be fast enough to win outright. Even faster if it had a rather simple looking (brown?) undertray for ground effects. The "innovation" on this car is that it is missing a whole lot of stuff. It has been KISSed. I don't know how many judges would recognise that. </div></BLOCKQUOTE>


Z.

This nearly describes to a "T" our original concept for our 2000 car. Unfortunately, that concept was shelved partly due to judging fears.

I'd still love to see a school do this.

Ramon

[Charlie]

Z I couldn't disagree more with pretty much everything you said.

Our 2003 car was made to be very simple. No it wasn't a brown go-cart, but it was very simple. We weren't trying to impress the judges we just wanted a good basic car to get our program on the right track (we decided we had been trying too hard to do things for the judges and not doing things the way we should have).

This car was not terribly innovative, it was a bit heavy and although it wasn't brown it was black on black. http://fsae.com/groupee_common/emoticons/icon_wink.gif We never expected to do well in design but as it turns out we were very honest with the judges and told them why we did what we did and we had a reasoned explanation for pretty much every choice we made (and maybe for the first time, we didn't try to BS anything!!)

We were shocked to get into design semis, even more shocked to finish 5th overall (tie for group just below design finals).

Don't get me wrong it's easy to get cynical about judging and I've been there, but at least as far as US judging goes your post couldn't be any farther from the truth. And from my FSAE-A experience I think you are wrong too.

[DJHache]

I agree with Charlie all the way.

It's no coincidence that the teams that make it into semis and usually do well in the dynamic events. The judges know what they are talking about and what's more, they probably know more about race cars than you do. If Doug Milliken thells you your desigh sucks, I don't think you should argue.

[Z]

You know what happens if you don't stir the pot? All the good stuff sinks to the bottom, and the froth and bubble rises to the top and forms a layer of scum. So I better give it another stir!

Denny,
I agree with most of what you say, except perhaps the part of having to "sell it". Shouldn't that be in Presentation? Your '99 performance (47D + 2E = 5th Outright) confirms what I was suggesting to Erin, ie. design doesn't matter so much if you're going for outright win. (Also in design one team's points don't effect the other teams. But in the dynamic events any team that wins an event by a long way pushes all the other teams backwards, pointswise.)

Suddenlee (Pat?),
There is absolutely no doubt that most people, even those in the highest positions, won't recognise a good idea if it is a TRULY NEW idea. My example of Fred Lanchester is only one of millions. That's what "paradigm shifts" aka "scientific revolutions" are all about. For example, I know that I can build a car (I have) with great and easily adjusted handling that has a torsionally flexible chassis. But I doubt that I could sell this idea to a "knowledgable" racer. The only way would be by winning (as Denny said) hence my earlier comment that "you might do better next year".

You also make the point that the designers have to "convince the judges they know why (the car is good)". So will the affable and eloquent young student of meagre design ability do better than the surly design guru with a paint-stripping case of halitosis? I accept that in industry an engineer has to be able to sell his ideas to his bosses. I just think that its a stupid idea. It certainly doesn't work on the footy field, where performance on the paddock is more important than a silver tongue.

Ramon,
I think you should have stuck with it. Your comment confirms that at least some teams may be compromising their outright scores simply because they are worried about their performance in the "Showpony" event. Design does seem to carry an unwarrated amount of prestige.

Charlie and DJ,
I think its great that you have had good judges. Good mentors are hard to come by. My point again is that I don't think any team should count on perspicacious judges. They will inevitably be making subjective opinions, but fortunately that doesn't matter too much for outright points.

Perhaps a more objective way of deciding Design points would be to wait til the end of the dynamic events, add all dynamic points and divide by Cost. This would be a measure of "bang for you buck", and in keeping with the saying "a good engineer is someone who can do with one dollar what any fool can do with ten".

[John Bucknell]

So....

Having been through a program where we continually sucked at design year after year - but did well enough dynamically to work our way from top twenty to top five overall in five years - I can sympathize with Z (my school a couple years later did well in design and the same year finished on top). However, you give us judges too little credit - selling isn't about being shiny and bouncy, it's about knowing your $hit. We'll ask you questions to see if you have basic understanding, and if you answer about right - we'll ask more detail to see if your design decisions were driven by your overall goals. All in ten to fifteen minutes. There is no innovation in racing at this level - just degrees of creative application. If you've done something special - we'll know it, and the 0.5% of the time we don't you had darn well point it out because you're proud of it. Every judge I've talked with is a deep expert in at least one field if not several - and objectivity is the rule rather than the exception.

However, I do think Z's last suggestion would prompt more creative application of cost analysis - in which case all the most experienced teams would do well. And we'd be back where we started.

[Fergus Wilson]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Z:
I agree with most of what you say, except perhaps the part of having to "sell it". Shouldn't that be in Presentation? Your '99 performance </div></BLOCKQUOTE>

Sorry Z, everything that you do involves some sort of selling. And any good sales person will sell BENEFITS not FEATURES. But unless you can justify your decision, you're only selling the judges on the features, not benefits. You might have 10inch wheels (feature), but the benefit could be lower weight.

The Presentation event has a different target - a manufacturing firm. Again, you're not selling the features of the car (that is only part of it), you're selling the benefits of their firm chosing to manufacture your car.

And off topic, the same applies to getting sponsorship - you need to convince sponsors of the benefit to them of sponsoring you, not just what they get.

Cheers,

Fergus

[Urvina]

So what I am hearing is that the judges care more about why you chose the design and parts that you did instead of how you put them together.

Wouldn't you want to keep it as simple as possible since the car is meant to be marketed to the "weekend autocrosser"?

[James Waltman]

Hey Erin, how are things going?
A simple car for the "average"� weekend autocrosser is a valid approach and probably best for a few years with a new team.

At the same time, I think that there is a market for a "high end"� FSAE car. Here is my proof. We go to some of the autocrosses with the University of Washington. Practically every time the UW FSAE car sets fastest time of the day ( by a healthy margin (http://www.wwscc.org/event_results/2005/slush1.html) ).

Stacey Molleker is often runner up behind UW. Mr. Molleker is an SCCA National Champ and his car has huge Hoosier slicks and one of these badges (http://www.corvettecavalry.com/yourvettes/tonyz-z06-badge.jpg) .
I bet Mr. Molleker would love to have an FSAE car so he could set FTD – even if it was one of the "expensive"� or "exotic"� ones. As long as it was the fastest one.

[Frank]

i got the impression that "marked improvement" provided the "team understood the design", counted most

[Denny Trimble]

Yeah, Mike T and Stacey ran in the last group of the day at that event, it dried out for them.

Even better, at the '04 SCCA National Tour in Bremerton, Stacey won his class (ASP) with a 96.8 two-day time. I brought home FTD with an 88.4. Official results are here. (http://www.scca.com/_Filelibrary/File/solo-04bwtour-sun.pdf)

We've had lots of comments at national autocrosses that people would love to buy one of our cars for $25k or so. They're spending more than that on the latest and greatest stock-class cars, and several of the top competitors buy cars only based on how well they fit the class rules for that year.

Realistically, you're not building the car for a weekend autocrosser, you're building it for your team to win in Detroit that year. But, if you build some quality into it - ease of maintenance, durability - you'll have a good testing and training rig for next year's team, and that's essential.

[Ben Beacock]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by James Waltman:

At the same time, I think that there is a market for a "high end"� FSAE car. </div></BLOCKQUOTE>

That is part of the justifaction for this year's car, since it seems like we're cramming every known goody we can into it: AWD, custom ECU, 2 way telemetry, LCD display, pneumatic shifting, and a few secret ones. They all affect the overall package/performance in a positive way except for cost. We're all EE, so the simple all-mechanical lightweight car mentioned earlier doesn't appeal to our strengths.

[Daves]

Ben,

I am impressed with Guelph's innovation. I look forward to seeing your 2005 entry in May. Do you think you'll switch the AWD to full time for the acceleration event? It seems that with all of the Guelph car's mass on the driven tires, the car should acclerate very well.

[Z]

Ok, here's my last stir of the pot.

Fergus,

"everything ... involves some sort of selling". So how do you use salesmanship to win Endurance? Or any of the dynamic events?


James,

If you can sell an exotic car for $25k, and it costs you $30k to build, are you winning? If you can build a simple car for $10k, and it is faster than the exotic, and you throw $1k of carbon composite and nickel plating (call it "unobtanium") at it, and then you sell it for $25k, are you winning?


To any Design judges,

Rule 1.1 : "challenge... the creativity, and imagination of the students".
Rule 1.2 : "the car must have high performance (and) be low in cost, easy to maintain, and reliable".

The majority of cars in FSAE are the "standard" model - 4 cylinder bike engine/gearbox, spaceframe, double-wishbone with push/pullrods and rockers, etc. This is a considerably more complicated and expensive car than a "brown go-cart".

On some of the links to FSAE sites there are recommendations from Design judges to first year teams to start with a "standard" car, and go more complicated later. There are few, if any, recommendations to be creative or imaginative (Rule 1.1), or to build the simplest, cheapest car (Rule 1.2).

So;
Are the subtle pressures of the Design event towards Rules 1.1 and 1.2, or away?

Specifically, is there any pressure to build a conventional car, with perhaps a dash of extra complication thrown in "to impress the judges"?

Why does Erin wonder how to impress the judges when the only option is to copy the standard car?

Why did Ramon's team ditch the "brown go-cart" concept?

Why, on another thread, did a team lose Design points because its engine was "not complex enough"?

Is there an "anti-kiss" bias in Design?

If so, why?????

Realistically, in Design, what chance would a well detailed, well understood, cheap brown go-cart have of beating a well detailed, well understood, expensive exotic?

Z

[little miss bossy]

Hey Z, judges are your friends. Well, you'd be advised to treat them with respect, anyway. Word from the wise http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

[Denny Trimble]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Z:
Realistically, in Design, what chance would a well detailed, well understood, cheap brown go-cart have of beating a well detailed, well understood, expensive exotic?
</div></BLOCKQUOTE>

Nothing ventured, nothing gained. Build it and bring it, don't let the fear of judges stop you.

I think you're building up an imaginary prejudice against your ideas as an excuse not to execute them. But that's just my opinion http://fsae.com/groupee_common/emoticons/icon_smile.gif

I really hope you build it. That's the only way you'll find out... anything.

[Urvina]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> </div></BLOCKQUOTE>yikes

[Urvina]

i need to learn how to use this forum before I try to build a car...


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Denny Trimble:
Nothing ventured, nothing gained. Build it and bring it, don't let the fear of judges stop you.
...I really hope you build it. That's the only way you'll find out...anything.
</div></BLOCKQUOTE>

I think that's what the team and I need to understand. And regardless of our absolute lack of experience, resources, and money, we can still build a car and get it to the competition.

I need to be more realistic about what we can accomplish. (But I am still secretly shooting for 1st place!)

Erin Urvina
University of Alaska Anchorage
FSAE '06 Team Leader

[James Waltman]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Z:
James,
If you can sell an exotic car for $25k, and it costs you $30k to build, are you winning? If you can build a simple car for $10k, and it is faster than the exotic, and you throw $1k of carbon composite and nickel plating (call it "unobtanium") at it, and then you sell it for $25k, are you winning?
</div></BLOCKQUOTE>
What I said was: "As long as it was the fastest one."
That means that if the turbo makes it faster the price offset may be worth it for some customers. Where did I say that it should be sold for a loss? The $25,000 price from the rules is the prototype cost. It does not have to be the retail cost.
I don't have anything against the go-kart concept. In fact, I like it.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Z:
On some of the links to FSAE sites there are recommendations from Design judges to first year teams to start with a "standard" car, and go more complicated later. There are few, if any, recommendations to be creative or imaginative (Rule 1.1), or to build the simplest, cheapest car (Rule 1.2). </div></BLOCKQUOTE>
I have been a team member and team leader for a group trying to build a "creative and imaginative car"�. It is unbelievably difficult. Since then, I have urged new teams to keep it simple. It turns out that even building a simple FSAE car is a huge task.

Z, have you been through the design event before? What school are you from?

-------------------
Erin,
We got a little off track for your question but it did get answered here.
Pat (Suddenlee) and John are both Design Judges. Go back and read what they said and what Denny first said. Then read the paper from Carroll Smith here:
http://students.sae.org/competitions/formulaseries/rules/
It should get you pointed in the right direction but you'll probably have to go through the competition once to really get the idea (I know I did).

[Ben Beacock]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Dave @ L.U.:
Ben,

I am impressed with Guelph's innovation. I look forward to seeing your 2005 entry in May. Do you think you'll switch the AWD to full time for the acceleration event? It seems that with all of the Guelph car's mass on the driven tires, the car should acclerate very well. </div></BLOCKQUOTE>

Theres a small team working on a neuro-fuzzy control algorithm specifically for the acceleration event. I've come up with a simulink model that includes clutch slip, inertias, frictions, weight transfer, compliance, and a tire model. Hopefully THAT will impress the judges(its .2 sec faster than the equivalent lighter RWD car, on a dry day with new tires) We had rough calculations last year, but we couldn't 100% prove it was faster so they were very skeptical and seemed unimpressed. We were also bitter about the innovation award going to the carbon fibre process which was more of a chemical thing than a design thing, and we think had alot to do with being top in design(sorry UWA).
Anyways, I think the judging is good, but not the process. 15 minutes isn't enough time to cover everything when you have a small team, even if they've already read the design report (which is too short).

[Z]

Ahh.. confession time,

[QUOTE]Originally posted by James Waltman:

Z, have you been through the design event before? What school are you from?


James,
No I haven't been through FSAE Design before, mainly because I'm out of school, hence ineligible for FSAE.

But I have been following FSAE for a few years, and in a few more years my boys may be in a school that is eligible to compete.

My point (in this thread) is that while most people pay lip service to "Kiss", very few actually follow it through. This is especially so in engineering where new designs are almost always overcomplicated. I have been fighting this for several decades, and sometimes I still find myself guilty of it!

It is very easy to overcomplicate a design!

It is much, much, much harder to come up with a truly simple ("elegant") design!

It is, however, much easier to build the simple design, and it is fast!

The reason for my ranting is that I see the standard FSAE car as way too complicated. For instance, push/pullrods and rockers are an absolute waste of time and money. Likewise double-wishbones (I could go on for hours about this, but maybe somewhere else). Unfortunately, the Design event seems to encourage this poor (ie. overcomplicated) engineering. Many teams seem to be swayed by this pressure. I am just offering an alternate viewpoint as to what I see as good engineering.

Maybe in a few years my boys can show you what I mean (but then again, boys being boys, they might "showboat" a bit too much).

Finally, despite your hard work, FSAE really is just a game - it should be fun! You're not in Iraq. There's no life or death, or even a mortgage to worry about. If you want to do something really creative/imaginative, then go for it. You won't get many similar chances when you leave school.

Z

[Mike T.]

I don't quite understand what makes a push/pullrod and double wishbone setup so complicated, nor why it is a waste of time or money. I suspect that if it were such a waste, any current CART, F1, or other respectable racing car would be a Formula Vee. And obviously, this isn't the case. I'd like to see you take your case for this 'poor engineering' to some of the engineers that design such cars.

Given the restrictions on our suspension designs, requiring 2" of functional suspension travel, etc., the principles that make a go-kart function so well don't necessarilly apply. This is especially so here in the US, where we do not run our cars on a surface as smooth as a baby's bum, but rather on an uneven, cracked, and uncared for portion of a 30 year old parking lot. I'd suspect that on that surface rates stiff enough to make the concept work effectively would likely result in a car that is easily upset to the point that it's almost undrivable.

It's nice that you wish to share all of your extensive expertise on the subject of our cars(and in your eyes our 'game'), which for many of us are our lives at this point in our education, but seeing as how it's almost entirely SUBJECTIVE ranting, would you please step down from your high horse, and let this discussion get back to what it was intended to be.

Mike Trumbore
UWFSAE 2002-2005

[little miss bossy]

Hmmmm, Z..... You wouldn't be my old friend, "devil's advocate", would you?? http://fsae.com/groupee_common/emoticons/icon_wink.gif

[Kevin Hayward]

It is difficult to post on something like this with our team placing first in US Design last year. Almost anything said may come across as high and mighty ... this is not my intention.

I did want to mention a couple of things though. First that I thought the judges of the US comp were amazing. We got absolutely grilled for about 6-7 hours by the time prelim, semis and finals were finished. I think that if any team makes the semis and isn't impressed with this time committment and thoroughness of the judges is a not giving credit where due. Maybe the prelim design is a little short, but that is merely a function of the number of teams.

We were not able to give a correct answer to a few questions that the judges had. But I don't think it really mattered. For example a judge can ask what your yaw momwent of inertia of the vehicle is. You can provide a number but without due analysis and a valid use for that number it is meaningless.

From what I gathered the judges were far more interested in a reasonable explanation of why things were done and that you understood things properly. In fact I think the design judging was more an analysis of the students than it was of the car. This certainly discourages teams from just pumping out the same car year after year ... cause if the students don't know the previous design inside out they get burnt.

I also think that the judges see a lot of things that are not on the car ... and are not visible to other teams. These include analysis of data, test procedures, manufacturing procedures, maket assessments etc. All things that contribute to the engineering achievement. These are certainly a part of engineering design as much as the detail design of components. Pugh's "Total Design" is a great text that deals with some of these issues.

When it comes to these sorts of issues I am thoroughly impressed by the approach of teams like Cornell. What may appear like a similar car on the outside year after year is the result of a team that has a team structure setup to make good decisions. The process of systematic design allows for excellence to be produced constantly. I am sure that the judges see this.

I am sorry that Ben is bitter about the innovation award. The Guelph car was certainly an impressive vehicle. However I don't think that innovation should be limited to the "things" on the car. A really simple rundown of what lead to the CF process innovation is as follows:

1. Assumption that monocoque chassis are superior with stiffness to weight than a spaceframe

2. Use of prepregs in monocoque chassis' is preferable.

3. No suitable autoclave in Western Australia

4. Low funds available to allocate to a CF project.

So despite wanting to run a CF Monocoque chassis for performaance reasons we were not able to. Hence by looking at the fundamental properties of the materials one of our students was able to invent a process that achieved superior results to an autoclave, in much less time, with much less capital outlay. I think that is a pretty innovative way to build a chassis of the required performance.

It was not based on the premise that this process exists and is suitable so lets use it. Rather the process was created out of the goals of the vehicle.

Which is what I think impresses judges. Identifying a problem and then systematically solving it.

Hope some of this waffle may help. Also hope that I didn't sound like a w****r.

Cheers,

Kev

[Urvina]

So what did Cornell do that was so impressive?

Erin

[Kevin Hayward]

Erin,

Unless I am mistaken they use what is called a systems engineering approach. I have found a bit of a quote that explains systems engineering better than I could (from : http://www.incose.org)

Systems Engineering is an interdisciplinary approach and means to enable the realization of successful systems. It focuses on defining customer needs and required functionality early in the development cycle, documenting requirements, then proceeding with design synthesis and system validation while considering the complete problem:

Operations
Cost & Schedule
Performance
Training & Support
Test
Disposal
Manufacturing

Systems Engineering integrates all the disciplines and specialty groups into a team effort forming a structured development process that proceeds from concept to production to operation. Systems Engineering considers both the business and the technical needs of all customers with the goal of providing a quality product that meets the user needs.

...

Basically it is a style of approaching the design problems. A lot of people approach design problems without giving due consideration appropriate design procedures. As I mentioned previously we use a sort of custom approach that is based on Pugh's "Total design" methods. We also include some of the fundamentals of Taguchi methods with a focus on robust design. However I cannot comment on its long term success until we have or have not achieved it.

Basically your vehicle will reflect on the type of design procedure you use. Systems engineering relies on minimising the risk arising from errors that have been shown to occur repeatedly in projects which use intuitive, ad hoc, de facto or simplistic approaches. This leads to vehicles that would probably not be radically different than to what has come before. However the approach also lends itself to being able to rapidly change direction. For example if a team is very successful with a new development it may be adopted very quickly by another team using a systems engineering approach.

For example you may know that Lotus was the first team to effectively use ground effects. It performed really well. However what most people do not acknowledge is that following the breakthrough teams such as Williams perfected the idea and were able to dominate teams like Lotus for many more years.

A systems engineering approach promotes continuing success. Of course some teams may come up and win on the odd year but the Cornell approach allows them to be competitive virtually every year.

That is what I think is impressive.

Kev

UWA Motorsport

p.s. To the Cornell guys I hope I got my interpretation of the systems engineering approach close to the mark.

[Chris Boyden]

I'd say that you have it down pretty well Kev.

After graduation, I got a job as a Systems Engineer, and I must say that I wish we could go back and apply several Systems engineering approaches to the design of our car.

Creating the requirements at the beginning of the process is something most people do with design problems, but generally not in very structured way. But getting the requirements into a document really forces the designers and system engineers to sit down, plan, and think about exactly what needs to be done. All of the steps used in the system engineering process can really pay off when it comes to design judging. If you follow the model, then you'll absolutely have valid and substantial answers to design questions, because the systems engineering process forces you to come up with them along the way.

The incose site is a great place to start. It may seem like a lot of uneccessary work to do these steps for every part on the car, but it can really pay off in the end.

copied from the incose site:

Most systems engineers accept the following basic core concepts:

1.Understand the whole problem before you try to solve it
2.Translate the problem into measurable requirements
3.Examine all feasible alternatives before selecting a solution
4.Make sure you consider the total system life cycle. The birth to death concept extends to maintenance, replacement and decommission. If these are not considered in the other tasks, major life cycle costs can be ignored.
5.Make sure to test the total system before delivering it.
6.Document everything.

[Urvina]

wow, that's really interesting...

i hope it wouldn't take to long to try to apply it to our team.

thanks Kev and Chris, that was very helpful

[John Bucknell]

I'm a systems engineer as well. That item #6 is the hardest to drive into a culture (even in a top company, because all organizations need to be disciplined - not just engineering, it is a business after all). Organizational learning processes make the organization robust so specialized knowledge is not lost when a critical member moves on. Keep all of your senior design reports (if you have them) and don't ever lose them - make them a reference work in your engineering library if you can.

[Chris Boyden]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Organizational learning processes make the organization robust so specialized knowledge is not lost when a critical member moves on. </div></BLOCKQUOTE>

That's a great way of putting it. It's tough to come up with the documentation for all phases of product development. But, it always seems like some question comes up down the line that could be easily answered if the documents were beefed up. People forget things, that's just the way it goes. I'm starting to follow an object oriented design process. Every design can be broken down into its different parts and levels of abstraction. This can be applied to all phases of the project. Anyway,
I'll get off the soapbox.

[Dick Golembiewski]

This seems to come up every year. Some of us go over this about as often. I did so on the old listserv, as well as here.

I am coming at this from the perspective of a motorsports chassis judge. The industry and powertrain folks might have a slightly different one.

First there is no "magic" that will help you do well in design. While we all have predispositions, I have never known them to influence the judging in any group I've worked with. As a group we tend to catch each others' prejudices, and things balance out in the end.

At FSAE in Detroit, we have approximately twenty (20) minutes to go over your design in the first round. I started requiring a 3-5 minute overall perspective of the students back when I first judged in 1999. It was something I required of my students when I was a faculty advisor, and we now recommend it to all groups.

We are generally trying to do a number of things simultaneously:

1. Evaluate the finished car - as presented - in order to assess the design:

A. You'll see many of us rocking the car back and forth to get a feel for the roll stiffness, ARB operation (You would be amazed at how many don't work, or have slop in them.), etc.

B. You'll see us bouncing up and down to get a feel for the stiffness of the car in jounce. (Gross amounts of bump steer will also show up.)

C. We'll be examining load paths, and your structure.

D. We'll evaluate ergonomics.

E. We'll look at how easy your car is to manufacture. (This is not a cost analysis, but we do look at it.)

F. Fit and finish is evaluated.


2. Simultaneously, we'll evaluate the team's understanding:

A. Did you have an overall plan?

B. Do you understand basic vehicle dynamics?

C. Did you use sound engineering design practice?

D. Did you back-up FEA with testing?

E. Did you understand why you did what you did, or did you simply copy a previous design? (We're coming down harder every year on teams that copy previous designs with little or no understanding.)

F. If necessary, can you document your work? We don't have time to go over every graphic, or table of data, but it helps to have storyboards, and organized books of data and design specifications - just in case we ask.


I tell the students in my design groups that I am not being rude and ignoring them, but rather I'm looking at their car rather than directly at them. It's all about trying to use that 20 minutes most efficiently.

After all of that we have a pretty good handle on what tier the entry belongs in.

NEVER BS! If you don't know an answer, say so.

Be enthusiastic about your design. If you're not, who will?

There is a balance that has to be struck between those last two statements. Salesman's "puffing" doesn't impress us. True confidence based on solid understanding of what you tried to accomplish - backed up with data and testing results - does.

Be sure the car is "race ready" when you show up. That's in the rules. Puddles of fluids, loose nuts, bad wiring, etc., don't make a good impression. Poor preparation often means DNS or DNF in the performance events.

If you don't make the design semi-finals or finals, use it as a learning experience. A number of motorsports judges are wandering around throught the weekend. Be sure to ask them to have a look at your car. You'll find that we love to do so.

As I always say, none of us are gods. The usual questions we get are:

1. What do you think of our entry?

2. How come we finished where we did in design?

3. How can we improve?

Those aren't necessarily the same question. I may not personally like some of your design decisions, but if you backed them up in your presentation, you may still score well in design. As such, be sure you understand what you are really asking.

I have a race that weekend at Mid-Ohio, so I don't know if I can judge this year or not. I'm hoping to at least get a disk with your design reviews, so I can have a look at them.

Good luck!

- Dick Golembiewski

[Dick Golembiewski]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Maybe in a few years my boys can show you what I mean (but then again, boys being boys, they might "showboat" a bit too much). </div></BLOCKQUOTE>


Just remember, Z, that if they do get involved it will be their project and not yours!

- Dick Golembiewski

[Z]

Dick,

Just to make sure we're "on topic". Erin started this thread by asking "how can we impress the judges... [when] it seems like all it is now is how well you can copy other team's cars." And later that they are "still secretly shooting for 1st place!"

My response was that, in my opinion, if a team wants to do well outright they should NOT try to impress the judges. Instead they should focus on winning Endurance, and to do so it would be easiest if they design/build the simplest possible car. Several other posts, from teams that have been there, done it, confirm this attitude.

What you are suggesting in your above post is that when a team enters this competition they should be working in some kind of vacuum. No outside influences whatsoever! This is clearly unattainable. To suggest so is denying reality. There are no clean sheets of paper! All new teams are heavily influenced by other FSAE efforts, and by other forms of circuit racing, particulary (and probably to the team's detriment) the high profile ones of F1, Indy, CART, etc. (eg. Mike T's post).

What I find particularly hypocritical about your suggestion is that, apparently, the Design judges are allowed to influence the teams' design decisions. From many posts above and on other threads it is obvious that many design decisions are made just to please the judges. The team that lost points because its engine was "not complex enough" were clearly being influenced by the judges to make a more complex engine next year.

And on another thread a judge tells a student who is proposing kart steering instead of R&P that he should "be prepared for heavy duty flack from the design judges ... if you use a low tech solution in what is primarily an engineering competition". I personally see this as a disgraceful, blatant coercion by the judge compelling the student (and any others who read that thread) to produce an unnecessarily complex design just to please the judge's prejudices (and in your first post you admit that judges do have prejudices).

In your first post you say that when you were the faculty advisor "I required [a particular approach] of my students". So is it acceptable for faculty advisors to REQUIRE certain aspects of design as well? If so, to what degree? And why? The answer is that of course faculty advisors have a considerable influence on the overall design of FSAE cars. Anecdotally, some faculty advisors have very specific requirements on design, and this may be why some teams do well year after year.

So, faculty advisors, judges, other FSAE teams, and even other forms of motorsport, can all have an influence on a team's design decisions. But you are saying that a student's father cannot suggest to his son what is good design philosophy? Sorry Dick, but my sons are not going to grow up in a philosophical vacuum. And if they are receiving undue pressure to produce poor designs "just to please the judges" I will do what I can to correct the situation.

Which leaves the unanswered question; "Is there an "anti-kiss" bias in Design?"

So, Dick, are you, or any other judges you know, prejudiced towards or against the KISS philosophy???

Z

[Buckingham]

Z -

In regards to your poor choice of an example of the steering system: The rack and pinion is soph/junior level mechanical engineering. If a custom steering system is too time consuming for a low-resource team, there are plenty of economical off-the-shelf rack and pinion options available. Regardless of whether the team in question didn't have the resources to produce a r&p design, the 130 other teams that show up with a r&p will have a better design, thus they will probably get more design points.

In response to your comment about unnecessary complexity, the rack and pinion is about as "unnecessarily complex" as right hand turns.

The design competition is not perfect, but if you have a better idea about how to throw 140 cars into a hat and decide which car is the best engineered, please share.

[Charlie]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Z:
My response was that, in my opinion, if a team wants to do well outright they should NOT try to impress the judges. Instead they should focus on winning Endurance, </div></BLOCKQUOTE>

That's exactly what we tried to do in 2003. In the process we managed to impress the judges. Go Figure.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">winning Endurance, and to do so it would be easiest if they design/build the simplest possible car. </div></BLOCKQUOTE>

That is your opinion and as an experienced FSAE'er I VEHEMENTLY disagree. Simple is good but on a case by case basis, not across the board.

[Dick Golembiewski]

Z,

(It would be preferable if you used a name and not a handle.)

My point is:

You are, of course, free to discuss any philosophy you wish with your sons.

They should be free to accept or reject any ideas you have. The design should ultimately be theirs and not their father's.

[Z]

Donavan,

Re: Unnecessarily complex R&P.
Make a R&P and a kart steering system from raw materials. Get an accountant to time you and cost the materials. Weigh both systems. Count the number of joints that can wear and develop slop in both systems. These are all objective measures of "complexity/simplicity". The kart steering (I would bet) is cheaper, lighter, more reliable. Now if they both perform equally well, why do you think that the R&P is a "better design"?

Re: Better way to decide design.
I suggested one objective way in a previous post - take dynamic points and divide by cost($). This gives a measure of "bang for your buck", a reasonable indicator of good design. But this will put the judges out of a (fun) job.

Charlie,

Re: Don't try to impress judges.
Yes, you did well - exactly my point! (as per para.2 of my last post)

Re: Simple car.
I don't get it. If "simple is good on a case by case basis", then how can it be bad for the whole car? (Earlier I said that good, simple designs are very hard to do. I agree that it takes more design effort to come up with a simple design that works well. That makes the "design" part of a project more costly. But does that mean that in FSAE you should strive for complexity?)

Dick,

Re: Who's project it is.
The rules are clear on this. It would be pretty hard to pass off a grey-haired old fart as a first year engineering student! Furthermore, these teams are quite large, so my sons (if they choose to enter) will only have a fraction of any decision making authority.

I have, and will continue to, let them make their own decisions/mistakes (well, except for the really stupid, costly ones - until they can pay for them).

But if "the design should ultimately be theirs" then why are the Design judges exerting so much pressure on the students!? This is the question I have been asking throughout this thread - and still no reply.

To recapitulate: this thread is about "how to impress the judges".

So, why does an engine that is "not complex enough" NOT impress the judges? Or why should a team be "prepared for heavy duty flack" if it chooses a simple steering system?

It has not been spelt out anywhere above what "KISS" means, nor has anyone asked, so presumably it is a well known philosophy. It is also a philosophy that is normally considered to be "a ggod thing". So why has no one, judges or students, put forth their views why "KISS" might be a bad thing in FSAE? (I have, briefly, under "simple car" above.)

So I ask again; Dick, will a KISS design score poorly (ie. will the brown go-kart NOT impress the judges)? If so, why? And if so, why is a "shiny" design more impressive?

Z

[Garlic]

KISS means "Keep it Simple Stupid"

NOT

"Keep it Stupid Simple"

What makes the car faster is the ultimate goal: SIMPLE OR NOT!!

Z, you are being ridiculous with your attempt to sway everyone that they are building cars that are too complex. What do you want? Is simple always faster? Friction brakes? One wheel-drive? Simple right?

You have a good cause because most FSAE cars are overly complicated. Too bad you totally went over the top and lost any credibility. That is, if anyone who's never completed or been to a FSAE event can have credibility enough to criiticize.

[Denny Trimble]

At the risk of provoking further philosophical debate, I beg to differ that a kart steering system is as good as a rack and pinion for FSAE.

1) Bump steer will be an issue because of the difference in tie rod lengths and control arm lengths (assuming the tie rods are connected to the steering column close to its centerline). FSAE rules require 2" of suspension travel, and the Pontiac parking lot necessitates it.

2) You can't specify a steering ratio slower than about 3:1 with a kart system and still get 25 degrees at the wheels, because of the nonlinearity / nonfunctionality of the kart system as steering wheel angle increases.

You could add mechanisms to solve both of these problems, but then you might as well go with a rack and pinion.

Here's my latest one-week-wonder:
http://students.washington.edu/dennyt/fsae/cnc/Rack_Complete.JPG

[Cement Legs]

Wow Denny thats pretty tight mill work to save those few grams from the corners on your center gear housing. Was that done on a 3 axis?

Oh yeah .... I agree about the cart steering vs rack and pinion http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

[PatClarke]

Quote Z "Ok, here's my last stir of the pot".

Okay Erik, enough is enough. Rather than sh*t stirring and philosophical arguments about KISS, why not contribute some of the excellent input you are capable of.
Enough is enough http://fsae.com/groupee_common/emoticons/icon_smile.gif
PDR

PS, Would a GoKart type steering system work with a patented "Balenced Suspension System"? http://fsae.com/groupee_common/emoticons/icon_wink.gif

[Denny Trimble]

CL,
Yeah, I squared up the stock and did the boring setups for bearings and bushings on the 2-axis CNC, then did 2 setups on the 3-axis for surfacing the top and bottom sides. Didn't even have to make fixtures this time http://fsae.com/groupee_common/emoticons/icon_smile.gif

I made the rest of the parts over the next couple days. We bought the pinion gear and rack from Stiletto.

[Daves]

Denny,

Speaking of parts you've designed, these (http://students.washington.edu/dennyt/fsae/cnc/Bearing_Mounts_1.JPG) are incredible. How in the world did you do all that milling? Are you using these differential mounts with an F4i and a University Special? Do you have any video of them being made? How in the world do you cost them? We made similar ones, and they are ending up costing over $200 for the cost report!

[Denny Trimble]

Dave,
Thanks, those were fun. Yes, they mount up to the swingarm mounts of an F4 / F4i. They hold our aluminum housing for a Torsen. This was our first year going away from an inboard rear brake, so we took advantage of the opportunity to go to an eccentric chain tensioning system. I had some fun with it, I'll admit.

The machining time wasn't that bad, even on our slow Bridgeport-based 3-axis mill. It really slows down on 3D surfacing, you can watch the machine shake as the lines of code go by, it's a 386 with 4MB ram. It won't take programs larger than 300K.

We have a 3-flute roughing endmill for aluminum, and it kicks some serious ass for Bridgeport mills. I've been running it at 50IPM, .150DOC, 0.5" stepovers with mist coolant. Watch out for the chips, they're heavy and hot. But, I'm sure all the guys with bigger, better, enclosed mills are laughing anyway http://fsae.com/groupee_common/emoticons/icon_smile.gif

I don't have any video, my laptop just died. We cost them as two CNC setups of about 15 minutes each, and manual labor for placing them in the fixtures. And that's about four times slower than the upright shown in the Haas video, so I think it's reasonable. That's for the "bearing mounts", the eccentrics were similar but with less machining time. I made them on the 2-axis.

[Urvina]

Well maybe I wasn't expressing myself clearly when I wrote the topic...

We want to do the best we can possibly do as a FIRST YEAR team. I assumed that in order to do that it means scoring any amount in the endurcance and doing well in design. And going into an event like this as a group that has no previous experience whatsoever and really has no idea what they are doing, I asked how we could impress the judges because that was the first thing that crossed my mind as how we could do well.

As far as keeping it simple, I think that would be the only thing we could do. We don't have the knowledge that other teams have to create a more complex car, but bravo if you can.
A

[Urvina]

AND what would be the difference between the go-kart steering and rack/pinion steering in terms of design and simplicity? I didn't quite understand what Denny was talking about when he posted that picture.


Erin

[Z]

Suddenlee (Pat),

-------------------------
Quote "Rather than sh*t stirring and philosophical arguments about KISS, why not contribute some of the excellent input you are capable of."
-------------------------

Thats' what I'm trying to do...

Re: Kart steering.

1. FSAE cars are very light so don't need high ratio steering.

2. FSAE cars need fast steering. 1/2 turn or less lock to lock is ok.

3. Bump steer is a function of the steering/suspension package. On another thread someone complains that, because the inner-bottom-wishbone-mounts where close to the car centreline, he couldn't make a rack short enough to eliminate bump steer. He could have mounted the track rods at the centre of the rack (a common solution), but kart steering would have been simpler, cheaper, lighter, more reliable - better!

4. From my reading of other threads, dynamic-toe behaviour (aka Ackermann) is still not very well understood in FSAE. However, and without going into the details here (I've done that elsewhere), a WELL DESIGNED kart steering will produce better dynamic-toe curves than a R&P, and hence better cornering performance. (Kart steering has two sinusoids to work with instead of R&P's one.)

But more importantly, kart steering is KISS! It is harder to design properly, but ultimately it is better.

So, Suddenlee, why should any team using it expect "heavy duty flak from the Design judges?

If FSAE really is about producing a better generation of engineers, then why the anti-kiss bias????

Kiss is widely considered to be a "good thing" - in many fields, not just engineering. It is a very hard thing to learn. FSAE would be a good place for students to start learning it.

I still await some justification/explanation for this bias. I will no longer ask "If" it is there, just "Why".

Z

PS. Garlic,
"Friction brakes" are too simple? What are you using? A quantum tunneling flux-capacitor...???

PPS. Denny,
Yes, that R&P sure is shiny.

[rwolcott23]

I would have to agree with Z on his fundamental argument. This competition is loaded with paradigms and there will be a team that comes along some day and shakes things up. The thing is that we like to challenge ourselves to make the perfect car and design the next best widget. If a FSAE car had to race head to head with a shifter cart it would be very humbling and ugly. Simpler designs do have the potential to be much faster.

In my opinion, the professional level cars are engineered to the current degree because the drivers are simply that good. Most FSAE drivers would never feel the difference between a theoretically perfect car and one that has design issues. FSAE car lap times are not limited by the quality of the car, but the lack of driving skills. If we designed these cars and had professional drivers race them for us it would be a different story. The more complex designs would be warranted.

It would take guts to go against the grain and build a super simple car, but I'd bet the team would be rewarded in endurance. Our program is currently producing a typical FSAE car and it is a truly monumental effort. It would be fun to do less design and fabrication, and more driving. Maybe next year.

I would bet that if this had originated as a racing competition (not engineering) the winning designs would be a little different and undoubtedly faster.

Bob

[Kevin Hayward]

Z,

I think that this thread has been unduly harsh on the design judges. From the few years that I have been involved I have never really experienced judges trying to force a certain design methodology on students. Apart from rejecting some very obvious things such as poor fastener selection, poor load paths etc.

If there are any expectations placed on the students it is the expectation that they explain their designs appropriately.

Some judges encourage first year teams to develop what is considered a "standard FSAE car" to begin with. This may be appropriate given that similar specs to a number of FSAE teams there is a lot of help available. However the biggest problems of a first year team are not in designing and building a car. Having been one of a couple of students who set up our team I am not in a hurry to repeat a similar experience. The judges comments and help in the beginning of our team were invaluable and really helped us find our feet.

It was Pat and Carroll that were continually repeating the phrase "Keep It Simple Stupid".

...

I have also spoken to judges that are waiting for the very simple single cylinder light car to be done really well. There have been attempts ... but nothing that has set the FSAE world on fire ... yet.

Anyway it is dissappointing to see that a thread that could have contained a lot of info regarding the process of making design decisions and their presentation to judges has degenrated into a slur of the judging panel.

Kev

[Dick Golembiewski]

Z (Erik),

I just discovered that this board has private messaging. (My apologies to those who have sent me some for the past few years. I was never notified of private messages, and didn't know (or check to see if) it existed.)

Now that I know your secret identity, I've sent you a private message.

- Dick Golembiewski

[BryanH]

."Z" Pat has convinced me page 1 of the rulebook is not meant to be taken literally, the object of fsae is to allow students to put theory into practice hopefully making them better/more employable Engineers.To that end their concepts need to be reasonably complex so that designing a competitive car requires serious research, building it extends their practical abilities and keeping it alive tests problem solving. In OZ this certainly seems to be working with many ex-fsae Grads. picked up by top level race teams. Do you think they would be interested in a Grad. whose claim to fame was building a "simple brown Kart"?

Denny, you were doing very well until you posted the r&p photo, why didn't you press/pin 4130 tubes into the centre section? would have been smaller, lighter, easier to make
Bryan H

[Cement Legs]

I really believe that the idea behind KISS is relative. We are a first car team, planning to test this summer and compete in 2006. So for us, we need to stay within the boundaries of our knowledge, experience, fabricating expertise, research ability and budget. So what might be simple to some other team may not be simple for us. The idea of keeping these simple is not to produce simple minded products, but to visualize a product that in fact can be completed and run successfully. Comparing Ferrari to FSAE is a stretch but if you said KISS at one of their design meetings it would likely mean kiss goodbye. Complicated systems are intended to do complicated tasks because the designer sees some inherent gain or benefit in the end. I know there is at least one team at FSAE and I cant remember which school they are from, but they ask themselmes a simple question before every decision. Will this make us go faster?

Obviously any decision that is taken to increase performance without drastically diminishing reliability or the likelihood that the entire package can be completed on time, in my mind can be successful. But the real problem lies in evaluating our own skills as engineers and fabricators! To me traction control is very complicated. To someone who has worked on one during freshman, sophmore, and junior years and then moves into team lead for that feature they are going to have a starting point leap years ahead.

Bottom line. Sometimes there are no simple solutions to achieve the performance characteristic you are looking for.

ie If it rains in Detroit this year debate this with the AWD teams http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

[Denny Trimble]

Bryan,
The original abandoned design I inheireted spring break called for pressed-in tubes, but I didn't like the idea of having to un-press them to change the bushings. Since this is a one-off rack, and I wanted to try a few different bushing materials on the aluminum rack, I wanted it to be very easy to maintain.

It was easy enough to put the bolt holes on the housing; I made the tubes the next morning, starting from square stock and turning them down to be flanged round tubes.

The tubes aren't OD-limited, so aluminum is more structurally efficient than steel in that application.

Overall, it was easy enough for me to make, which is all that matters for FSAE. On to the next project...

[Marshall Grice]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">If a FSAE car had to race head to head with a shifter cart it would be very humbling and ugly. </div></BLOCKQUOTE>

I agree it is, for them. a good fsae car is faster then a shifter cart, at least for autoxing. Shifter karts (http://ww2.scca.com/soloresults.php?ID=45)
fsae cars (http://ww2.scca.com/soloresults.php?ID=64)

[alfordda]

Its not limited to autox's. We've done some testing at a kart track, and they usually pull away in the twisties and we catch up in the straights. I'm sure a good formula car and driver combo could take a shifter kart at that track.

[rwolcott23]

Okay, based on the autocross results I'd say the two are equal in performance. My point is that the shifter cart has a fraction of the FSAE car's complexity but matches the performance.

Bob

[Denny Trimble]

Sure, but the rules are wildly different. If we could, I'm sure several FSAE cars would look like shifter karts. But, a few rules get in the way:

-No 2-strokes allowed
-Suspension required
-Minimum wheel diameter 8"
-Roll hoops, Crush Structure required
-Harness required
-60" minimum wheelbase

Don't compare apples to oranges.

[rwolcott23]

Denny,

I understand that the rules specify all of those things and I am not trying to compare apples to oranges. I am illustrating that it doesn't necessarily take a super duper suspension, turbocharged, ultra deluxo race car to get around a race track quickly. A kart shows that it can be done with no suspension at all.

At one end of the spectrum is the FSAE car with all of the bells and whistles and the other end has a shifter kart (which is illegal for our competition). I would guess that the fastest FSAE car would be somewhere in between.

Would you disagree that if this competition originated strictly as a racing competition the cars would be just a little bit faster after twenty years under a slightly different approach (strictly results based)?

I am open to the possibility and that there might be simpler way to get fast lap times and I am a little surprised that there has been so much hostility towards Z's argument. There are many people with closed minds out there that apparently have this competition completely figured out. I am open to the possibility that the best (fastest) solution might not be overly complex.

Bob

[BryanH]

Bob, when the RMIT/Rotor combo runs at Detroit the question may be partly answered, RO4's design owes nothing to a kart so is not strictly to "Z"'s recipie. But it is reasonably light,low polar inertia, and on track looks and drives just like an ICC kart. The one place where a kart is much faster is skidpad, due to IMHO the pad being too small to give meaningful results for the fsae cars.
Iv'e been driving a 94'Lotus Esprit a fair bit lately and it's probably the best balanced fastest point to point car I have ever driven. But in tight roundabouts it like a Hippo on a muddy riverbank!
Denny, is your phone # 6061harlot?
I love the stuff too.

[Denny Trimble]

Bob,
I agree that shifter karts are a more elegant and simple approach to the problem of getting a driver around a course. But, I think the rules make it more difficult to design a truly simple FSAE car. Even the cars I've seen with beam axles seem to be just as far from simple and elegant as the "conventional" double a-arm cars.

I'd love to see a very well-executed, simple single. RMIT and Delft are pretty much there, I don't know why we haven't seen one do well in Pontiac yet. Who knows, maybe if we have the right crop of guys this summer, we'll have to bring one in '06.

Bryan,
You can reach me at I-LUV-7050 (home), or I-LUV-7075 (cell).

[Eddie Martin]

As i see it FSAE is a learning experience. It's about taking engineering students and teaching them to become engineers, so when they enter the workforce they have a head start.

The KISS principle is very important but I guess it comes down to what you consider simple. Designing a double wishbone push/pullrod system isn't that easy, but at the same time its not brain surgery. This competition is primarily aimed at students who want to enter the automotive / motorsports area so designing a double wishbone push/pullrod suspension system is great experience for that career.
Many graduates of Wollongong have gone on to careers in motorsport because of the experience and knowledge they gained through fsae. If we had a "brown go-kart"� i'm sure it would have been more difficult for them to get into those careers.

When RMIT's car goes to the states in May and people watch it in the autox and enduro I'm sure a lot of people will change their minds about singles. I'm pretty sure there will be a lot more singles in 06. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Chris Boyden]

I don't have any experience with shifter karts,
but it seems like a really rough parking lot
would reek havoc on a shifter kart.

[Z]

Quote
-------------------------
"Even the cars I've seen with beam axles seem to be just as far from simple and elegant as the "conventional" double a-arm cars."
-------------------------

I agree. I am guessing that the team that I saw (in pics) with front and rear beams chose them for their advantage of no wheel camber change with body bounce, pitch, and roll. Unfortunately, they then went and complicated everthing by using "Mumford links" (if I remember correctly) for lateral location. These in addition to 3 (or 4?) ball-ended links for longitudinal location.

Mumford links are a complicated way of getting a ground level (or below) roll centre. They are moderately useful for a heavy live rear axle (ie. with diff. in it), on a light car, with low RC wishbone front suspension, on rough roads. So not that useful for a FSAE car. No offense intended to the team, but I think they were "showboating".

As noted before, KISS isn't easy. It takes quite a bit of self-discipline. As someone else noted, the designers should always be asking themselves "Will this make the car faster?". I would add "HOW MUCH faster, for the extra kg/$/...?".

If anyone is thinking about beam axles then the simplest approach might be a Model T Ford layout with peg-in-slot lateral location. That is, a beam (hollow tube!) with two torque reaction arms converging to a single ball-joint on the centreline of the car (thus forming a triangle with apex at BJ). Lateral location via a pair of roller bearings fixed to chassis and running in a vertical slot at the centre of the beam. Something similar was used at the rear of the 1930's Mercedes GP cars.

Other than camber control, the other big advantage of beams is that you can run a highish roll centre (say 5-15 cms in FSAE) without suffering from jacking. This in turn means that the springs can be softer, for better grip over bumps. Lateral load transfer distribution can be adjusted by RC height (front vs rear), which gives quicker response than LLTD via springs/ARBs. Also front and rear beams make it very easy to mount a live ground-effects undertray.

Z

[BryanH]

Cris,
A sprint kart doesn't seem to care how rough the track is. The limiting factor is the driver's mental toughness and race fitness!
I speak from personal exp. having been beaten up on rough street circuits, but there is no pain until sunday night.(cro/mo sheet taped in bottom of seat essential)

A sprint Kart is faster than a shifter around fsae sized tracks, lighter & no time wasted on gearchanges.

[James Waltman]

Z,
How about a suspension system like this one:
http://dot.etec.wwu.edu/fsae/HostedPics/James/from_Patent%236,702,265.JPG

[Chris Boyden]

Bryan,

Do the karts recover pretty quickly from a good
bounce? Without a suspension, it seems like the tires would lose contact and upset the car on rough and chunky pavement.

Regardless, it sounds like fun, except for the sheet metal seat. my bony ass likes things soft.

[Z]

James,

Yes, or perhaps better is the simpler version of Figure 20 (Figures 21 and 22 (above) are a bit of showboating). You'd better check with the author first.

Beams axles front and rear are easier for the typical team to understand, and more than adequate for FSAE conditions. If they start doing "FSAE in the Dirt" (Baja with 80+hp) then the above (& Fig. 20) would be better.


Chris,

Karts have a form of active suspension - the driver! This sort of suspension works best if the driver is standing, as on quad bikes, or mountain/motoX bikes. It isn't quite as good when the driver is sitting, hunched over the wheel - his/her backbone has to do most of the work (although a well endowed "her" might have a good level of inertial damping). It is almost non-existent when the driver is reclined and tightly strapped down to a rigid seat - just some fillings rattling around in their cavities.

One reason racecars on very smooth tracks still benefit from some damped suspension movement is to damp out any bouncing of the car on its tyres. Tyres have very low internal damping (unless at very low pressure), but even on a smooth track they can develop a slip/stick/jump/bounce... motion during cornering. The damping can be from a conventional suspension, or from "inertial damping" of a roly-poly driver sitting on a lightweight, suspensionless kart. (A good excuse for the driver to stay away from the gym?)


Z

[ERIN BLONC]

I agree whole heartedly that the design judges are human after all and it is our job to sell the designs. In saying that when we were judged it was just before lunch and I blame our score on the judges being hungry!

[syoung]

Maybe you should have bought them a burger while they were judging your car!

[Dick Golembiewski]

I suppose we could post our prices... http://fsae.com/groupee_common/emoticons/icon_wink.gif

- Dick

[TheoD]

A little history in the Brown U solid axle cars.

Back in 1996, when we started a serious effort to participate in the FSAE competition, we came late to the game... First tubes were cut in mid November without a "complete" design. All the design was done on paper etc. The choise of solid axles was based on their simplicity of manufacture, the use of alot of F440 parts and the benefits of no camber changes during steering. The axles on the first car were located by a peg in a slot.... And it was fun....but not fast with a carb engine and 700lb due to the use of 1X2 inch beams for the chassis. (it also used torsion springs and friction dampers...)

The following generations of the cars remained on solid axles as we contuned to fine tune the design. The Mumford/Mallock links permited us to have a controled roll center that did not move all over the place (just up and down) as the car rolled. The suspension was soft (we did move 1.5 inch on a regular basis) unlike the stiff cars using A-arms. The drivers were driving something that behaved more like their road cars instead of a race car and could better understand what the car was doing.

Over the next 5 years we developed a very good understanding of the advanteges and disadvantages the solid axles. We have placed 6th in 2000 and 10th in 2002. So that shows that solid axle cars can compete in FSAE successfully while being simple to make.

The mumford link is simple to make and does not require the accuracy of A-arms welded in a fixture... For an A-arm car there are 8 a-arms needed. That's more chances to mess things up (Opportunites for Error) For the solid axle car there were 1-2 mumford links

As for "showboating". I must admit we did take pride in the fact that we were different and we were making it work.

Theo Doucakis
Brown FSAE 92-03

[Z]

Theo,

Firstly, I congratulate your team for having the courage to try something that is different and simple. Also for sticking with it.

No offense was intended with the "showboating" comment. This was meant more as a reference to most people's belief that "complicated" is better than "simple". I agree that 2 Mumford links are certainly easier to do than 8 a-arms. I reckon 2 peg-in-slots would be even easier. With the pegs mounted to the chassis, and Model-T type beam-axles, there is no movement of the roll-axis (relative to the chassis) at all.

Z

PS. Its also good to hear that you had fun! That's probably the most important thing to get right...

[Matt Gignac]

Hey Denny

Where did you find a supplier for the Stiletto pinion and rack seperate?

Matt Gignac
McGill Racing Team

[Denny Trimble]

Uh, Stiletto. I forget the actual contact info, but we got it direct from the people who make it.

[Captain Redbeard]

it's Woodhaven industries. They are very familiar with FSAE and will make you whatever you want. Any length, aluminum or steel, whatever. The number is 815-732-2806 and the guy to talk to is Gary.

-Redbeard

[ErickN]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Denny Trimble:


The machining time wasn't that bad, even on our slow Bridgeport-based 3-axis mill. It really slows down on 3D surfacing, you can watch the machine shake as the lines of code go by, it's a 386 with 4MB ram. It won't take programs larger than 300K. </div></BLOCKQUOTE>

The machine "shakes" because you are sending less code to the machine than what the machine is needing to read to keep up. try increasing your baud rate if you are drip feeding code through a dnc program otherwise you will need to slow down your feedrate so the machine buffer stays full of code. hope this helps. 10 years of CNC programming here.

[J. Vinella]

You brought up an old post. Denny is no longer on the team, but I'll keep that in mind. Thanks.