I guess my teams 2nd place car at FSAE-M is no good.Quote:
Originally Posted by Claude Rouelle
Though I do wonder what the weight sensitivity to lap tone is. Maybe we could have been 1st...
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I guess my teams 2nd place car at FSAE-M is no good.Quote:
Originally Posted by Claude Rouelle
Though I do wonder what the weight sensitivity to lap tone is. Maybe we could have been 1st...
Julian,Quote:
Originally Posted by JulianH
Ah, that is the only type of pre-event that we do. We have our faculty advisor rigorously scrutinizer our car. I was more referring to the formal pre-events like Formula North, ZF race camp etc, mini-competitions.
Noah
Formula North is a "real" competition; not a mini-event.
ZF Race Camp is just a nice help for all ZF sponsored teams. As written above, I really like this event, it helps to "calm" the team members that never experienced competitions, you have a lot of fun and see how the others are doing it.
Can you tell me why you think that your team would be not able to participate in such an event? Let's say it would be ~4hours drive from your university (which is probably the average time that it takes all ZF Race Camp teams to come to Southern Germany).
Will,Quote:
Originally Posted by Will M
The answer to your question above, as I see it, is in the mini-essay below.
However, I have no idea what "...the goals of the FSAE leadership" are. For the last 30 odd years they have certainly NOT appeared to be interested in improving the teams' reliability, because they have provided very little "external pressure" to fix that problem. In fact, in Oz last year they rewarded the unreliable teams!
~~~~~o0o~~~~~
HOW TO MOTIVATE A DONKEY.
=======================
Traditionally, you use the "carrot and stick" approach. Depending on circumstances, you can use one, or the other, or a bit of both.
For example, if the donkey is starving, then dangling a carrot in front of its nose works great.
But if the donkey has just gorged itself on a basketful of carrots, and you hang a second basketful of carrots in front of it, then, for obvious reasons, the donkey thinks, "Are you kidding..., I'm about to explode!".
And he sits down and moans about how bloated he is.
~~~o0o~~~
CASE STUDY 2.
=============
For the few years around 2006+, RMIT was the top team in the world. Then they fell in a big hole, and have never recovered.
~o0o~
Two years ago RMIT-C came to 2015-Oz-comp with an as-close-to-mini-F1-car as you could imagine. Full-CarbonFibre-monocoque, CF-wishbones-with-push/pull-rods&rockers, longitudinally-mounted (ie. F1-style) turbo-charged 85+ hp Yamaha Genesis/Phazer engine (WITH 3-D-printed-titanium-exhaust-manifold), followed by a bespoke 4-speed-CF-cased-gearbox, followed by a viscous-LSD, ... and many other shiny things.
Suprisingly, given the lightweight-twin engine, their claimed mass was a rather portly 185 kg (though probably more, see below). But with all this bling abounding, who cares about some objective numbers? Certainly not the Design Judges, because they gave them,
Design Event points = 140.. Yep, second-place in DE!
And how did this smoking-hot, mini-F1-car perform on track?
Well, TOTAL Dynamic points = 54.4!
So, all things considered, a complete success!
Huh? Why?
Because, as one RMIT-C Team-member explained just a few days after the competition (see 2015-Oz-comp thread),
"Seriously the aim of all this is to ... get a job [and] Two of our members ... have landed employment off this project..."
Clearly, the "carrot" in FS/FSAE is to "get a job". That is most easily done by producing a lot of generally useless, but very shiny, junk, which impresses the DJs enough to give you very high points in the prestigious DE, which then puts you at the front of the queue for that high-paid job.
~o0o~
So, with the 2015 Team-members well rewarded with carrots, which direction do you think the 2016 Team-members were motivated to take?
Well, they arrived at 2016-comp with an all-but-identical car to the 2015 car. The only obvious change was that it had one less gear. And, somewhat confusingly, despite their spec-sheet claiming a mass reduced to 175 kg, the scrutineers' scales said it had porked-up to ~215 kg (both w/o driver).
So, with the mass comfortably above Dunk's suggested minimum, did this mean they had built a much stronger car, with the aim of increasing reliability and thus completing all Dynamic events?
Nope. Their TOTAL Dynamic points = 45.1. Worse than last year.
But Happy Days, again!
Their Design Event points = 136.9. Just a smidge below last year's.
Surely good enough for a walk-up-start at any top-paying job.
~o0o~
So, ... with the 2016 Team-members given another basketful of motivational "DE carrots" to munch on, in which direction do you think the 2017 Team-members will go?
Will they focus on the boring complete-all-Dynamic-events reliability? Or on the get-a-high-score-in-DE bling, and then off to that dream-job next year?
Z
(PS. Claude, I agree 100++% with you that the teams should do a great deal more testing. But try convincing them of that! I might post another mini-essay soon about some of my futile efforts to convince teams of such. :()
That's not very nice Claude. I was merely proposing a thought experiment.Quote:
Originally Posted by Claude Rouelle
What I do get, is that most teams break down because they made X part 'too thin' , and didn't have time to test it properly because they spent it all trying to save even more weight. You've said as much in your "Test, Test, Test" post.
I am playing devil's advocate a little, because I know a lower weight limit does not solve the root cause of the problem. But to do that means somehow forcing the team to do thing s like full FMEA's, proper timing plans, etc. Which would make the whole competition very unappealing, especially when most engineering students call it: "Formula Stupid, that competition where all the cars break down."
I am currently in the position of said 'poor employer'; often supervising new graduates at work. There a lot of lessons that I want them to have learned. But FSAE students don't go away saying, oh we should try to implement better failure mode avoidance. They talk about fixing that one thing and then making their car "lighter, more powerful, faster, etc, AND more reliable."Quote:
Originally Posted by Pat Clarke
I had a 12 month industrial placement leading up to my final FSAE year. During which time I did a ton of research and spent most of my lunch breaks on here and slowly learned not to focus on mass over reliability, mostly thanks to Big Bird's wise word. We went from a DNF team to finishing all events.
Sometimes to learn something people just need to be told. Then they start asking and understanding why.
Your welcome, this was partly my intent.Quote:
Originally Posted by Z
Competition results made available online already do this.Quote:
Originally Posted by Z
The problem is, I was in a team with really good engineers, but I also with some people that should be banned from ever doing engineering professionally.
So looking at the result of the whole team doesn't help much. If the standard deviation within a team is high, then you have no idea what you're getting.
I don't think DE should be dropped, but changed to: Engineering Event. The work 'design' has far too much association with aesthetics, an not how something actually works, or why.Quote:
Originally Posted by Z
I'd like to see it broken into two parts, the Specification and Validation sides of the system V. Starting at a high level, of how they believe they can perform at comp, all the way to what each individual part specification. Then back up through how they they tested their engineering against all their performance targets, and ultimately how they performed at the competition.
The DE purports to do this already. But there is no true attempt to check any of the validation work, if simulation and testing is not done properly, then the results of these a worthless. There is no way of checking these have been done properly, except.... dynamic events. All you have to do is run the design event at the end of the weekend, AFTER all dynamics event and you have all the validation you need.
You can compare their predictions to what they achieved. First you judge if their targets/predictions were fair, considering their resources, then you compare these to their actual performance, and have a discussion about why their not the same (be it a large or very small difference), and score according to their understanding.
Why not include this as part of the DE submission? We require that teams designs the car themselves and judge them on this, so why not require that they test their car as well?Quote:
Originally Posted by Claude Rouelle
If they are meeting their goals, then those goals are not about satisfying employer requirements.Quote:
Originally Posted by Will M
Learning from mistakes is great, but first you have to know what that mistake was. I fear this is rarely the case. Teams will just correct the one thing that went wrong and come back the next year and something else will break. The mistake was not the design of the car, but the way in which they went about engineering the whole project.
This is great if you're being watched by an expert swimmer. But pretty reckless to do on your own.Quote:
Originally Posted by Claude Rouelle
(Academic staff are rarely expert swimmers).
Now this is an idea I can really get behind, and the sort of thing I was hoping to get out of this discussion.Quote:
Originally Posted by Kevin Hayward
YES. THIS!!Quote:
Originally Posted by Claude Rouelle
This is Failure Mode Avoidance, a standard industry tool I know well, and there are much more rigorous ways of doing it that just standing around the car (although that may come into it). The problem is that most team's don't do this, and unless something changes about the competition and it's rules they will continue not to. We can say it's their responsibility all we want, but at the end of the day, it's our responsibility as educators to make sure their are learning to use the right tools, if they could do that on their own there would be no need for FSAE in the first place!!Quote:
Originally Posted by Claude Rouelle
This is exactly the sort of comment that is such a problem. Someone as respected as yourself saying something so judgmental of teams with 200kg+ cars is going to make those team bias their decision making towards low mass, and sacrifice reliability. They will make that mistake, where they otherwise wouldn't have because "Claude Rouelle said we had to be sub 200kg. So logical engineering decision making be damned, we'll just make sure we hit that target."Quote:
Originally Posted by Claude Rouelle
In the last 10 years the two most successful cars my team ever made weighed 250kg, and 225kg. The first was our best ever finish at competition, and the second saw the biggest jump in reliability and results for a number of years. The long term goal each time was to refine those concepts to reduce weight. But, too much focus on weight due to a design judge comment after the 250kg car landed the team with a 200kg car that wasn't any quicker and broke all the time. Following the 225kg concept (ran for 2 years), the team vision fell apart due to new management; they wanted to earn the praise of people like yourself and mandated a super lightweight car. They were the worst year in our team's history.
(I could make a joke here about the reasons people no longer want to listen to experts, #Brexit, but I won't).
But my team aren't the only example. I've spoken to so many teams who go on about getting a sub 200kg car. It's an obsession that needs to be removed for this competition to progress. Sub-200kg might be the right thing for most teams if done properly, but that needs to be a result of proper engineering decisions.
I tell you what, if my team are ever in a position of doing really quite well, and have a car that weighs 199kg, as unlikely as you may claim that to be, I'll make sure they add 1kg of ballast, just for you, Claude. ;)
Dunk
Lost of verbal diarrhea, tentative of justification, pretty pessimistic views, lack of YES WE CAN / WILL MAKE IT HAPPEN attitude, not very useful.
But you give me chance to elaborate on an important point
You wrote : "What I do get, is that most teams break down because they made X part 'too thin". Nope that is not that is not necessarily because the parts are too thin. The goal is to maximize tire grip AND reduce forces on each suspension and chassis part with smart design. It is all about how you distribute the tire forces and moment on your uprights, suspension, chassis etc... That is why design judges ask students to demonstrate both choice of materiel and shape of chassis and suspension elements tanks to load path calculations. Working on the part thickness will improve stiffness and reduce compliance....which will increase the forces on car parts (F= MA). Vicious circle. Think about the way a force of 450 N can be applied on a 0.3 mm egg without breaking it.
LOW MASS DOESN'T SACRIFICE RELIABILITY: WITH SMART DESIGN LOW MASS DOES IMPROVE RELIABILITY!!!!!
****
"In the last 10 years the two most successful cars my team ever made weighed 250kg, and 225kg" BS. What does it prove? Ask your former team members what they would have done if they would have had the choice to add or remove 10 Kg? How come we have several reliable winning cars circa 150 KG or less? (and do not tell me that is because they have bigger budget; I will ask back: do they win because they have budget or do they have budget because they win?)
******
"Why not include this as part of the DE submission? We require that teams designs the car themselves and judge them on this, so why not require that they test their car as well?" Again Outside-In solution. It is up to the team to do it. Inside-Out. Do organizers and design judges need to hold the hands of 17 - 24 years old?
*******
Claude
Julian
I am not suggesting to optimize everything. Your team design and run very competitive, light and most of the time very reliable cars. Every time I (and other judges) speak with your team members in Design (often in finals) it is a pleasure to see your knowledge and enthusiasm. You may have many assets starting with your excellent university (although we have to wonder why some even more prestigious with bigger budget universities such as MIT or Harvard or Cranfield do not show up - or if they show up perform poorly in FS - I have my opinion - but that is another debate) but I guess that despite you have nearly new team members every year, one of the main reasons your team is often on top is that you have an organized system of transmission of information from one year to another.
Here is my point: Big or small budget that is what many teams seem to be missing: they do not seem to have learnt from mistakes from previous years.
My name is Simon and I have been with the Running Snail Racing Team (UAS Amberg-Weiden) for four years now (I have done the software for the cars).Quote:
Originally Posted by Claude Rouelle
Of course the scrutineers need to be qualified. And yes, many issues met in inspection are avoidable. In the last year we did not have any issues in scrutineering at all, but the reason for that was mainly because those who where responsible did it in their second or third year. Normally, most of the people are in their first year and they make mistakes. Pre-events are helpful in these cases.
I totally agree with you on that inside-out-approach, but there is no reason not to do both. In fact, many of those great teams actually attend pre-events (e.g. AMZ, Delft, Karlsruhe, Stuttgart, ... the ZF Race Camp).Quote:
Originally Posted by Claude Rouelle
When I talked to the teams I got the impression that many break downs also happen because of battery issues (BMS, empty, heat), electronic problems, sensor problems (electric cars) and failed attempts to restart at the driver change, leaking fluids, other engine or clutch troubles (combustion cars).Quote:
Originally Posted by Dunk Mckay
However, when talking to teams that suffered mechanical break downs (too thin parts etc.) most of those teams were way below 100km of testing, many of them did not test at all and did parts of the car assembly. A weight limit would not change very much in my opinion, because those teams would still do their first meters at the competition and fail.
The best solution to improve results and reduce mechanical break downs is IMHO just to force the teams to do more testing. So as you suggested in the first post, a vehicle status video where the team must prove that the car is running properly would be great for every competition. However, I would not give additional points for teams that are able to provide the video, but instead just exclude all teams that fail to provide it (about one month before the competition).
Those teams can be replaced with teams from the waiting list that were able to build a running car. FSG does this already (although until last year, you could apply for an exception). This should be communicated to all of the teams and would built a lot of pressure to get the cars running in time. Also I feel that a team that failed at the registration quiz but was able to built a running car deserves it more to take part at a competition than one that succeeded at the quiz but did not build a running car in time.
It would be interesting to see, how testing corresponds with reliabilty/success. At least for my team, there is a clear dependence:
2013: ~600 Test-Kilometers before the first event, 1 pre-events, 3/3 Endurance finished (6th FSUK, 7th FSG)
2014: <100 Test-Kilometers before the first event, 0 pre-events, 0/3 Endurance finished (17th FSG, 15th FSA)
2015: ~150 Test-Kilometers before the first event, 2 pre-events, 1/3 Endurance finished (24th FSG, 3rd FSH)
2016: ~600 Test-Kilometers before the first event, 3 pre-events, 3/4 Endurance finished (4th FSG, 1st FSH)
Have been enjoying this thread. A bit of history, when I started design judging (c.2000) in Michigan, Design Finals were Sunday morning after Dynamics were over. By then, only about a dozen judges were left to talk with 3-5 FSAE teams and look at their cars. After talking with the teams, we sat in a circle and came to a final ranking by simple vote or consensus. Reliability played large in our decisions.Quote:
Originally Posted by Dunk Mckay
When the schedule was shortened to remove this final event on Sunday morning, I was quite vocal in my objections.
Someone may have a better explanation for the change, my understanding was that shortening the event by a day was a large cost saving. It may have been part of the move to Michigan International Speedway, which is (I think), quite an expensive facility to rent and use?
Here in Japan, we have several pre-events. Pre-events consists of scrutineering and dynamic events. Attendance is not mandatory, but many teams attend 3 times a year. Once in spring, usually shortly after their shakedown test, once in early August, and once in late August. The competition is held in early September.Quote:
Originally Posted by Claude Rouelle
Recently, we also do some scrutineering seminar for teams. In the seminar, scrutineers teaches students about the scrutineering, and answer to students' questions.
We also award all the teams who completed all the static events and the dynamic events.
We might be too indulgent with the students. We might be helping them too much. But, we are not satisfied with the rate of DNS and DNF. The Japanese car industry do care about reliability ;)
Dunk,
Thanks for your considered replies. I was afraid we overwhelmed you.
The end result would be the same.Quote:
I don't think DE should be dropped, but changed to: Engineering Event...
I will briefly restate my case for dropping Design Event (or a renamed "EE"), in case I was too subtle in previous posts.
I see DE as a massive inducement, effectively a "basketful of the juiciest carrots imagineable", that pulls the students away from building a boring, reliable car, and towards building an unnecessarily complicated high-tech marvel of modern engineering ... that cannot turn its wheels. The RMIT-C car of recent years is just one of many such examples.
It might be argued that Design Event only offers 150 points worth of carrots, against the 600+ carrots on offer from the Dynamic Events, so its "negative pulling power" is not excessive. However, the students clearly see "success in DE" as having a much greater influence on their future job prospects than "success on track". I say "clearly" because in my face-to-face discussions with students, whenever I urge them to "...simplificate, because it adds reliability!", I am most often met with sceptical looks, then "But, ... how will that go down in Design?". It seems that all design decisions must first pass the "...will it impress the DJs?" test.
Furthermore, "success in DE" requires working in a comfortable, indoor environment, in front of a CAD screen, drinking coffee or energy drinks, and eating pizza. Yes, there are many hours of this "work" to be done, but it is EASY work that most students enjoy. On the other hand, as noted many times in previous posts, "success on track" involves much TESTING. This requires much loading and unloading of trailers, changing of tyres, standing for ages in scorching-sun or freezing-rain, getting grit in eyes and grime under fingernails, and generally being completely knackered by end-of-day. In short, the "success in DE" type work is by far the easier option.
So, the "success in DE" carrots are both much tastier ($s!), and also a lot easier to reach, than the "success on track" carrots.
So the donkey naturally walks towards the DE-carrots, and away from the on-track-carrots. Water flows downhill.
~o0o~
The above is my summarised case for dropping DE from the competition.
Now, if this was a discussion about "how to build our next car", then the above arguments should be responded to in a WELL-REASONED manner, namely using "logos". It would NOT be good engineering to simply accept a pathetic (from "pathos", remember) argument to keep DE, such as, "I just like it. Call it a gut-feeling ... but, it has to stay.".
(By analogy, I note that exactly these sorts of pathetic arguments are almost always used by students to "keep the 600-four", or "keep the push/pullrods&rockers + ARBs", and so on, rather than trying to reason their way to a simpler, more reliable solution.)
So, below is a brief example of a logos-like approach to deciding this issue. (And, yes, the full logos approach is even more long-winded, boring++. Sorry!)
~~~o0o~~~
COST-BENEFIT ANALYSIS of DESIGN EVENT.
=====================================
COST of DE.
==========
1. Large number of officials (the DJs+) are needed for many hours. In terms of man-hours, DE probably accounts for more than any other single event.
Even in a small competition like Oz, almost 40 DJs and assistants are required for a full day. (And at 2016-Oz, almost all the DJs then spent ANOTHER ~8 hours quibbling over whether ONE team should lose ONE point because their 2016 Design Report was almost identical to their 2015 DR.)
2. DE is a distraction that interferes with the students' ability to build a car that can complete the dynamic events.
This is by far the worst "cost". This point can be debated, but if true, then it means DE is a huge impediment to the students' education. By analogy with a car's performance, DE is an anchor that is slowing down the education of the students.
~o0o~
BENEFITS of DE.
==============
1. Hmmm? ......... The DJs like it! (Why else would they spend a whole day quibbling over ONE point?)
~~~o0o~~~
In anticipation of some counter-arguments to above.
1. "But, DE gives the highly talented and experienced DJs an opportunity to give hugely beneficial advice to the students."
So, why, after ~30 years of such advice, are there still so many DNSs and DNFs?
Clearly, any such advice is NOT WORKING.
IMO, this is because the DE format is ill-suited to giving such advice. Not enough time, wrong pedagogic setting, too many cooks giving contrary advice, etc.
Furthermore, any "teaching" value that is claimed to exist in DE can be implemented, much more effectively and cheaply, elsewhere and in other ways.
EG 1. The recently out-of-work ex-DJs can educationally critique each car during scrutineering. Quicker, less "costly", more effective.
EG 2. Claude, or any other ex-DJs, can give such "design critiques" of ALL the cars, with ALL the students attending, at any convenient time during comp. Much quicker than the full day of DE, with much more coverage as all students get feedback on all cars.
~o0o~
2. "But, DE gives some DJs a great opportunity to sift through the many students, in order to find the better ones to whom they can offer jobs."
FS/FSAE is supposed to be about the EDUCATION of young engineers.
The competition, ITSELF, is NOT a "Careers Fair"!
If companies want to hire students, then they can pitch their "We Want You!" tents somewhere adjacent to the competition, but in a way that DOES NOT DISTRACT THE STUDENTS from building a car that WORKS.
~o0o~
Well-reasoned Cost-Benefit type counter-arguments for keeping DE are welcome.
Z
(PS. Again, apologies for above long-winded logos. Sooo much easier to go with those quick-and-easy gut-feelings, innit! :))
While I enjoy these dissertations from future Employed Engineer hopefuls, let me add a simple comment as a wake-up call to those still looking for an education:
There is NO WAY a manufacturing company of ANY product would host a Design Review after a production submission has been built and released for use. Design reviews are held at the minimum monthly and often weekly until ideas and concepts start to harden and flow from design GOALS.
Even the Formula Sewing Machine top management would want to review, comment, direct, criticize, fund, explore parallel Alternate Solutions, and review timing of such a deal.
This begs for a DE event to be held by FS BEFORE cars would be built and shipped. Concepts, drawings, part lists, costs, durability projections, materials, headcount, sourcing, powertrain, safety, emissions, noise, competitive assessment and a bunch of other pertinent Product Engineering 'Features' could/should be submitted for DJ-ing and when laugh track is quiet, a Team would be authorized to proceed. In my day, that's what a Faculty Advisor did. Anybody remember that for the very first ever event, it was a requirement that a car make it through the PG car wash intact ? That tidbit caught a few as I distinctly remember.
Maybe this means that the DE Review is done for the next year's cars. Maybe its done via Skype, Power-Point or papyrus or stone tablets. But, students who march into a Product Proposal meeting with Marketing execs having a 'finished' product on the table will quietly be sent out for training to make good onion rings. I've seen a few of these cats come and go.
As for testing, there are quite a few avenues for this topic: Free body diagrams, plastic models, scale models, computer multi-body models, mules, alpha and beta full size hardware. ALL intended to estimate loads and displacements of the critical parts and players in a machine. I'm reminded of the 1982 GM F-body front strut tower design review. ADAMS was used to design adequate structural integrity of this architecture. Sure, the prototypes lived through all the max pot hole events in the durability schedule. All those wonderful rainflow fatigue counts were within spec and nothing broke. But did anyone notice that the front strut mounts were dimpling the front hood and sheet metal ? Took a while, but loads AND displacement constraints must be reconciled.
One more thing, stuff you 'engineer' has to meet 'foreseeable misuse' sign-off. If your driver misses a shift or hits a cone, what does a Damage Report going to tell about what to expect and how to proceed.
Seems to me that there could be some reordering of these reviews. Let's see the design intent first, then try to build it. Have mass targets, speed and brake constraints, analysis and a Bill of Process (that's what it's called) which shows the lawyers you have been educated. If 'you' says it's too complicated or too time consuming or too much work, rework your team to be more efficient. Otherwise as far as the Industry is concerned, you are just playing in a sandbox.
Rule 1: Allow 2 stroke engines up to the same cc limitation as the the four strokes. (they are all restrictor limited anyway, right?)
Rule 2: Allow down to 6" diameter wheels.
What could possibly go wrong.
Not sure a 2 stroke engine would pass the emission test at Student Formula Japan...
I challenge you to get me and a 2 stroke powered car to Japan and we shall see about that.
Some barriers to entry are trivial.
Barriers to entry? Which barriers? To entry where? Student Formula Japan plays by the same rule as US FSAE and I can confirm that many foreign teams are very welcome and I can attest they are treated equally to any Japanese team many team are welcome.
By the way they have a public combined design review and final that is unique, run by Ono Massa, probably the most experienced engineer and best design judge I ever met, and is very useful to ALL students
2 more pics
Claude, you just said:
It sound like you think two strokes would struggle to qualify to enter the FS Japan competition based on their emissions output.Quote:
Originally Posted by Claude Rouelle
Sounds like a perceived barrier to me.
M Coach, Yes that is what I meant and in total honesty and ignorance (I am not an engine guy and even less a 2 stroke engine guy) I have to say I could be wrong. Just walking in the street of Indian or Vietnamese cities made me doubting the emission efficiency of 2 stroke motorcycles. But I am open to some education here. I also have to say that my post was somewhat irrelevant as FSAE rules do not allow 2 strokes engine.
In any case if any new engine type had to be allowed in FS/FSAE I think hydrogen/fuel cell should be the choice. Providing of course (back to the beginning of this thread) the car weights less than 200 Kg!
There are some amazing personal watercraft and snowmobile two stroke engines available these days that I would readily consider for a power source for these cars. Emissions have come a long way with direct injection and active valve technology. They really are a world away from the Indian used engines you mention.Quote:
Originally Posted by Claude Rouelle
To expand on the argument for my rules 1 and 2 now that my hook has caught a big fish:
Two stroke engines have the ability to reduce complexity and weight of these cars. Many are lightweight and easier to work on. This would allow for lighter cars, as well as potentially less DNFs.
It is my opinion that some of the light weight cars could be running even smaller tires than the 10" wheeled choices used now. No one uses 8" wheels because the tire compounds are substandard.
6" wheels are the next step down, have significantly wider compound selections (even greater than the 10,13" choices) and the packaging constraints would readily push students towards simpler construction.
Would everyone go this direction? Not necessarily. Just like everyone hasn't converged to a single design direction already.
Currently today there are teams that use up to 15" wheels and engine displacements of 250cc up to the limit of 610cc. Some teams are also planning to push right up to the new limit as well.
The two stroke engines would potentially come at a cost of decreased fuel efficiency and power under the curve. Leaving it up to teams to decide if their power/weight requirements overrule their fuel efficiency and packaging requirements.
The 6" wheels would allow more compound choices but at the risk of no data available currently and a substantial loss of longitudinal contact length and potentially overall grip.
Both of these options are also available at lower costs than their counterparts for the budget minded.
I think opening rules to allow the cars to safely become lighter and simpler through lighter weight and simpler choices would help DNFs so the students can take the weight out of one more location. Rather than feeling confined to running certain choices such as the 13" tires and sport bike motors and then desperately trying to hit weight targets by running carbon monocoques, carbon suspension links, and undersized hardware.
Some notes on emissions:
Hydrocarbons are formed due to rich clouds (or homogenous rich mixture), which are usually formed in 2 and 4 stroke engines by running fuel rich. They can also come from short-circuiting of the fuel air mixture through the cylinder, which tends to happen on 2-stroke piston ported engines with aggressive port designs. And finally, they can come from misfire.
Carbon monoxide is formed due to incomplete combustion, usually because of a rich cloud, and generally also appears in 2 and 4 stroke engines running rich.
Nitrous oxides are formed when there is excess oxygen and high temperatures, this requires lean combustion or stratified combustion. It is most prevalent with Diesel engines and turbine engines as they are stratified, but can be produced by other engines too.
Soot is formed when there is a very large excess of fuel in the combustion cloud, and carbon particles form. This usually happens with extremely poor mixing or stratified combustion (especially Diesel, which inherently has a rich cloud as the fuel spreads out before ignition), but I have seen a Briggs roll coal too.
**************
In 2014, the SAE Clean Snowmobile Challenge emissions event winners were as follows:
#1 emissions - SUNY Buffalo - 952cc IDI turbo diesel
#2 emissions - University of Idaho - 800cc DI 2-stroke SI
#3 emissions - Kettering University - 600cc PFI turbo 4-stroke SI
The point is that the engine calibration has a much bigger effect on the exhaust emissions than the combustion cycle. A modern 2-stroke or 4-stroke powersports engine will have roughly the same emissions, with slightly more HC from the 2-stroke.
**************
I think that engines in FSAE should only be limited to either fuel or air flow, and left otherwise unrestricted in size and design. Fuel restriction would be ideal and allow lean/stratified engines of similar power (including Diesel and turbine engines which inherently flow more air for the same power), but air restriction is much easier to implement. The rules change to 710cc makes that limit less relevant, which is overall a great thing.
2 stroke for the win! Kawasaki h2 750 w/ big fat expansion chambers all the way! or rg500, or nsr, or i could go on all day.. actually, at UTA's autocross weekend a couple years ago a guy had a formula car w/ a rotax 2 stroke. looked killer w/ those chambers on it. not sure the displacement on it.
Here's a slightly less radical suggestion:
Each team's Design score is scaled by the percentage of dynamic events they finish. (DQs counted, but not DNFs.)
An exception can be made for teams that want to compete as "Class 2" (statics only).
Here's another suggestion:
Hold Design after Endurance.
If your fancy system doesn't fail, great - you can boast about your unicorn-powered turbo 2-stroke hub motors.
Otherwise, a constructive discussion can be had on what went wrong and why.
Tim,
Be realistic
- You would have to wait the end of the endurance to run the design final? Ask the organizers what they think about that.
- You can have a very well designed an manufactured car that fails in endurance for a stupid reason (shit happens) as stupid as a flat tire and for that it could not not win design....? What objective measurement will you use to weight that?
The solution is less point in dynamics and more in static. Many judges have been asking for that. The racing virus and focus at all cost on the performances instead of the knowledge behind the performance has been taking away the goal of the FSAE founders and the spirit of engineering learning that students can / should show in design.
I still do not get the relevance of Class 2. UK is the only organization that does that and I wonder why. Either you build and run a car or you stay home.
In theory it would be a good Thing to have the design Event after all Dynamic Events. This would give the judges the possibility to observe the cars on track and later discuss what they observed with the students. Also failures could be discussed and evaluated. The Problem is that as an organiser you want to Keep the whole Event as short as possible as the rent for the venue and Hotel rooms for judges and volunteers are the biggest cost issues. The critical path in Terms of competition Duration are the dynamic Events. If you have 40+ Teams you will Need two entire days to run the dynamic Events. Before that you Need enough time for scrutineering. You can run the Static Events parallel to scrutineering but not parallel to the Dynamics. Having the design Event after the Dynamics would essentially mean to have one more competition day than at the Moment. This is impossible for most Events.
In General I'm biased towards the design Event. In my opinion it is a great Thing in theory. But in reality it is a highly subjective way of scoring. Very often you have judges coming from Event Sponsors who aren't even familiar with the rules. In my opinion at the Moment the students already tend to do a lot of complicated stuff for the design Event and Forget to build an actually working car. Therefore I'm not a friend of increasing the Points of the static Events as this would encourage this trend even more.
As I posted earlier, no theory, this was reality! It was standard procedure for Michigan with 120 cars entered (100+ arrived), for many years. I don't know the actual history, but it's quite possible that Carroll Smith created this schedule, along with all the other work that he did to elevate the status of Design.Quote:
Originally Posted by Bemo
Michigan Design Finals were Sunday morning after Dynamics were over. The last couple of years before the change to current schedule, this was held at a General Motors facility at the Warren Tech Center -- 3-to-5 Design Final cars/teams in the big lobby early in the morning and the remaining ~dozen Design Judges caucused before lunch. This was followed by a banquet lunch and prize-giving in the large corporate cafeteria for everyone that was willing to stay (wild guess, 500-1000 people). There was no need to rent the expensive facility for Dynamics on Sunday.
I believe that this is the right way to do it. It will take a lot of effort to regain what has been lost, but it is possible!
I think Doug has a point.
Claude,
You have me baffled.
You say,
I agree with you completely. If the car doesn't run, then stay home. Yes!Quote:
I still do not get the relevance of Class 2. UK is the only organization that does that and I wonder why. Either you build and run a car or you stay home.
But just prior to above quote you said,
Huh? Doesn't this move the whole competition TOWARDS Class 2?Quote:
The solution is less point in dynamics and more in static.
The ultimate extrapolation of your "solution" IS Class 2. It is NO Dynamic points, and ALL Static points.
~~~o0o~~~
As a by-the-way, we have now finished the third month of the Australian FSAE season, so more than a quarter of the way through. Over these last 3 months I have spent significant time talking to several of the Oz-teams, all of which FAILED TO TURN A WHEEL at 2016-Oz-comp.
The talking from my side was mostly along the lines of,
"Very easy to get top-5 here ... just keep it simple ... but MUST finish car early ... then LOTS OF TESTING!"
The response from the students is nodding of heads to the "...top-5" part, then sceptical looks and evasiveness on the rest. Nope, they are certainly NOT at Uni to learn how to load trailers, and all that other "hands on" stuff. Nope, they seem to be thinking, "This is an ENGINEERING DESIGN competition!!!.
And, indeed, in the current FSAE RuleBook we find,
"ARTICLE 6: DESIGN EVENT...
Comment: Teams are reminded that FSAE is an engineering design competition...".
But (!) this is despite the fact that the RuleBook opens with,
"ARTICLE 1: FORMULA SAE OVERVIEW...
A1.1 ... Competition Objective ... challenge teams of university ... students to conceive, design, FABRICATE, DEVELOP and COMPETE with small, formula style, vehicles."
(My extra emphasis. And elsewhere in the Rules is also mentioned the importance of good Project Management, meeting deadlines, and all the other necessaries required to have a car that turns its wheels.)
Clearly, the overarching goal of FSAE is a lot more than just having a FSUK-Class-2-style "...engineering design competition".
Anyway, my prognosis is that the teams I am talking to will, yet again, FAIL TO TURN A WHEEL at the 2017-Oz-comp. The lure of Design Event is simply too great. So much easier to sit in front of a CAD screen, doodling all sorts of really cool stuff, dreaming of how impressed the DJs will be with all that brilliant bling...
Z
There are two types of people in this world -- those who extrapolate from incomplete data.Quote:
Originally Posted by Z
Caroll Smith held design finals after endurance was completed starting in 1996. I think that changed when Jay O'Connell took over lead design judge in 2004.
I do not post much in here but this topic of design before/after dynamic events hit a note with me.
From my experience in design at both MIS and Lincoln for the past 6 years, I have seen good things and bad. I believe design should be after endurance for many reasons which have been commented on here as well as a few others. Yes some cars in design finals do not finish endurance, sometimes for uncontrollable reasons but I believe that is far and few compared to all the failures I have seen. I have seen teams who were in design finals fail for basic issues such as parts falling off because they weren't bolted down correctly, over heating due to not taking the hot temps in Lincoln into account, having major failures too such as suspension arm failures or engine failures. If you are a design finalist car, you should NOT be having these failures as much as I have seen.
Based on MIS and Lincoln for the past 3 years, the amount of design finalist teams that have not finished endurance is 50%. Half of what is considered the best designed cars in the entire competition aren't finishing a 22 km race? There has to be either something wrong is the way the design competition is scored, what the judges view as winning cars, or something else but I believe putting design after endurance would bring this number of design finalists that don't finish endurance way down.
It is frustrating as a competitor too to see your hard work be graded so low in design, and even still scoffed at in design review even when your car finishes higher than other team's who were considered 'the best.'
I hope to see the organization of the events change so that this can be taken into account.
I propose a new rule. (It's so simple, you'll love it).
Design judges have to bring their own FSAE car to comp.
That would be rather interesting!Quote:
Originally Posted by Jonny Rochester
You're on. We call it Texas Autocross weekend.
https://www.youtube.com/watch?v=6D5CN2wT-gk
Jonny,
That is exactly what Geoff Pearson suggested way back in February 2013 on the "Fantasy Car" thread.
http://www.fsae.com/forums/showthrea...ll=1#post16636
Here is the gist of Geoff's thinking:
"I've always had this desire to build an "Anti-Technology Special":
- Steel spaceframe
- Swing axles F&R
- Direct acting shocks
- Pitman arm steering
- Spool
- 10" aluminium wheels
- air-cooled single cyl engine
- carbureted
- balsa bodywork (with a nice baltic pine stain)
- No aero
- No carbon
- Something made of dried kelp
Objective - build the simplest, lowest parts count, lowest process count car possible within the rules...
I reckon it would be a good challenge, cheap, easy to build, and I'd love to see how close you could get to the front with it..."
~o0o~
A few pages later Geoff added:
"Re: the intent behind the Anti-Technology Special
...
The purpose would not be to prove that the fastest / best / sexiest racecar in the world would be aircooled, have [swing-axles] and would look like a rabbit hutch on wheels. Rather, I would love to build it just to set a benchmark for everyone. Give ourselves a modest budget and arm ourselves with a modest workshop (mig welder, lathe, tool box, wood saw etc. - a slightly upmarket farm shed), and do our best to build an honest little racecar.
The rules of engagement would be something like this:
- Gather a team of, say, six competent people, each with full time jobs
- Define time limits - e.g. no one person may spend more than two hours a day, or ten hours a week total, on the project
- Define budget - e.g. investment pool of $2000 each
- Define standards of behaviour - e.g. tools down when any of the following are on the telly: Bathurst 1000, any MotoGP, Classic Restos, Blokesworld
- Define material and process boundaries - e.g. no materials or processes allowed that were not available to an engineer prior to 1948
- No calculators or computers allowed - slide rules only
- Plans to be drawn up on drawing boards, in correct third angle projection
Design, build, test and develop the car within a twelve month period, then take it to the local FSAE competition and put it up against all the university-entered, over-designed wonder-cars. I doubt it would win, but I doubt it would finish last either. A decent amount of time testing and driver training, and it would set a very useful benchmark for performance - the definitive FSAE performance baseline. Now that would be educational."
~o0o~
To summarize Geoff's goal:
Six blokes, twelve grand, working weekends only, to set a benchmark of "minimum performance" that all University Teams should be able to beat.
To which Geoff added:
"And any team that finished behind the ATS would be sentenced to six months barn construction service in their nearest Amish community - just to make sure the lesson was learnt."
~o0o~
Back when Geoff was running the show here in Oz, I am sure something like that ATS would have happened. But nowadays there are no indications from the Oz-Officials that they are interested in that sort of educational approach. In fact, just the opposite, with their "Speciality Awards".
However, if the officials here ever decide that "education" really is THE priority of FS/FSAE, then I will quite happily build such an ATS. I will build it myself, for less than six grand, and let any ex-Oz-FSAEers drive it for unlimited laps in Autocross, and one stint in each Enduro. (Hey, I want to have some fun too!)
But (!), I would insist that Geoff's last quote above be slightly altered to:
"...any team that finished behind the ATS would be sentenced to crawl the length of the track on their hands and knees - just to make sure the lesson was learnt."
This, of course, would include all teams that DNS Enduro!
~~~o0o~~~
A SMIDGE MORE SOCIAL COMMENTARY.
================================
About 3 weeks ago I provided a "Cost-Benefit" type analysis of why Design Event should be dropped from the competition. I then asked if anyone could provide a similarly rational, well-reasoned, C-B type analysis that came to the contrary conclusion, namely that Design Event should be kept. After all, I might have missed something in my reasoning?
Well, the subject quickly changed to two-stroke engines. Then there was a longish period of silence. Then the discussion restarted with talk of how DE could be altered slightly, for example by holding it after Enduro.
But NOT A SKERRICK of cold, hard, boring, rational, "logos"-tical type discussion of the merits, or otherwise, of DE.
Nothing unusual here. Just the same old decision making via pure pathos.
WHAT THE STOMACH WANTS, THE BRAIN MUST GIVE!
Jonny, I am sure you have seen a lot of this in the last 3 years. For example, when your team "decided" that it MUST switch from that slow-old-single, to your awesome new, tyre-shredding-600-four.
Ahhh, what could have been. A better "engineered" version of your 2014 car would have won last year!
~~~o0o~~~
Want better "educated" young engineers? Drop DE, and let me bring an ATS!
Z
Just last week, I had to get UTAS 2014 car (brown go-kart with single, but too wide, no plenum) back on 4 wheels, because it's going to our museum. No joke.
Our 2015 car (and 2016) was a huge progression, and I wouldn't go back. UTAS 2015 had very few bells and whistles despite the 4cyl, and was basically reliable.
UTAS16 was much better again (10", good steering feel, aero, launch control) but as you would predict, some of the bells and whistles started to fall off it.
Personally I do want our 2016 car (and so does other people, see driver swap thread) with better engineering and quality so bits don't fall off.
But... I'm told that would be too easy, so UTAS this year are "tyre shredding" 2-rotors of electric power, with more than just a few bells and whistles required for basic operation.
What could possible go wrong? It should be more powerful than all the petrol cars because when I ask, I'm told "80kw".
But as Bill Heslop says "You can't stop progress".
The conundrum. I believe I can build a car that doesn't fall apart for 22km. I'm old, I've trade experience, I built too many of the parts on our FSAE cars, and I've been able to predict our own failures.
If I work to fix the little things, other students will just rest on that and work harder to introduce new unknowns. I just have to make sure the 2 parts I make for it are perfect, and walk away from
responsibility of finishing endurance.
Eventually we all get old, and we pick the best era that relates to our own capabilities and we build a historic racecar in the shed from that year. (For me it's a Group A Corolla Levin, 1985). But I
do believe we should allow current students to participate in engineering of the current day.
Perhaps finishing endurance is not what the young students want or need? Maybe the need to (be seen to) participate in the current technological push is a bigger driver?
Well said! If you want to see the different paths that design judges, tech inspectors, and other ex-FSAE folks take with their personal FSAE cars after the competitions are long-since over, look no further than Texas Autocross Weekend. Simple non-aero cars that are well-driven, 600lb aero cars with all the electronic gadgets that are well-driven, and current year FSAE cars that are well-driven are typically all represented in the top 10 finishing positions of each course throughout the weekend. Notice a common theme? :)Quote:
Originally Posted by John_Burford
Texas Autocross weekend proves what most of us only figure out much later in our racing enthusiast "careers"; any car can win if it's well-executed and well-driven. REIB vs sphericals, featherlight vs 600lb, 10" vs 13" wheels...all of these work fine from a car performance standpoint if you simply finish the car early then burn up a bunch of tires finding/fixing the weak points AND training your drivers.
I think I would have some nice cars for that ;) Granted the batteries are probably not good enough to last 22km anymore but I would bet our 2012/2013 cars would still run Top10ish in AutoX ;)Quote:
Originally Posted by Billzilla
If I'm ever selected as a design judge, I can bring my Briggs kart, to sweep the courses before the FSAE cars go out, and lay down benchmark times. Its chassis is older than some of the students competing, and it has eight (8) horsepower.
If you lose to it, you will have to go to the practice track and drive it. That will teach you by experience what Claude and Z try to tell you about the virtues of a low center of gravity, light weight, and simplicity of operation.