Upright Design

[Brent Howard]

Anyone remember what team, or have a picture of a team in Detroit with Uprights made from ERW square or other larger diameter tubing? I remember one that was gold and I'd really like to simplify our uprights by using tubing rather than laser cut plates.

Brent

www.ucalgary.ca/fsae (http://www.ucalgary.ca/fsae)

[Denny Trimble]

Ours were pretty simple last year.

http://students.washington.edu/dennyt/fsae/Comp_Pics/uw/images/chalk_dust.jpg

University of Washington Formula SAE ('98, '99, '03, '04)

[RiNaZ]

hey denny,
is the front upright the same with the rear too? and i notice that the rod ends mount is welde to the upper A-arms. Any reason why? (im still new in suspension design)

RiNaZ

[Mi_Ko]

Looks nice! http://fsae.com/groupee_common/emoticons/icon_smile.gif

Which material have you used? HSS? The collor looks like an special surface coating.

2002/03 University of MARIBOR - Team Member

[Didier Beaudoin]

It looks like bare chromoly to me.

Didier Beaudoin
Team Leader -
École Nationale d'Aérotechnique

[Denny Trimble]

The material is 4130 tubing, and the finish is powder coating. The front is a similar design, except it uses shims for camber adjustment (which we're going to use in the rear this year).

Rinaz, I think you're referring to the pullrod being attached to the a-arm. In the rear, attaching the pullrod/pushrod to the upright is possible and probably favorable. We're looking into that this year as well.

University of Washington Formula SAE ('98, '99, '03, '04)

[Brent Howard]

I think yours are the ones I was thinking of....but for some reason I was picturing tehm painted gold.

Thanks Denny

www.ucalgary.ca/fsae (http://www.ucalgary.ca/fsae)

[Alejandro]

Hi Denny, I remember your car, it was pretty cool, it`s a shame that you couldnt finish the endurance event because of some problems with the bodywork. And too bad the accident after the competition too.

About your Kodiak wheels. I noticed that the hub pad area is not at the same level as the billet center is. Do you machined the billet center? Because thats how our wheels were supose to come. Or at least that´s what their specif. sheet says.

PD: You were one of the guys that jumped tires with us at the end of the competition?

www.formulasae.grupos.usb.ve (http://www.formulasae.grupos.usb.ve)

Caracas-Venezuela

Alejandro Rondon
Universidad Simon Bolivar
www.formulasae.grupos.usb.ve (http://www.formulasae.grupos.usb.ve)

[Frank]

i'm really curious as to what those things weigh, just the cro-mo upright alone

(im not baging 'em they look light)

frank

[Denny Trimble]

Frank: 2.3 lbs each, .088 degrees camber gain due to structural deflection of the upright alone (FEA). We already have a new design that's the same weight, a little more difficult to make, but has 45% less deflection. But I'm not sharing that just yet http://fsae.com/groupee_common/emoticons/icon_smile.gif

Alejandro: I remember some people talking about jumping with you guys... something about "crazy people from Venezuela". For the wheels, those are direct from Kodiak. I think the "brake clearance" dimension on the spec sheet is what controls the machining of the hub-side of the wheel center.

University of Washington Formula SAE ('98, '99, '03, '04)

[Charlie]

What load case was your camber gain Denny, if you don't mind me asking.

-Charlie Ping
Auburn University FSAE (http://eng.auburn.edu/organizations/SAE/AUFSAE)
5th Overall Detroit 2003
? Overall Aussie 2003. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Denny Trimble]

1.6 lateral g's (sustained, on hot Hoosiers) leads to 450lbs lateral force on the outside rear tire in our case. Neglecting driving/braking/bump forces, this is a 4500 in*lb torque on the upright in the positive camber direction.

Anyone else have weight and stiffness numbers for comparison?

University of Washington Formula SAE ('98, '99, '03, '04)

[Frank]

yep 500 Nm bending here

I look for 100Mpa in the stress concentrators

using 2024T351 ally

in my mind I'm being VERY conservative

the rear upright weighs 0.9 kg with steering arm and (6) 5mm bolts to connect them

http://www.users.bigpond.net.au/franko/rear_upright.jpg

about $450 AUS for each side
about $150 AUS each side in cost report

been crack tested heaps, no probs

the only issue was dealing wif the losers at apollo metals to get the ally

regards

Frank

[This message was edited by Frank on November 05, 2003 at 05:49 AM.]

[Charlie]

We are working on 04 upright design right now.

Got out 04 Cheif engineer to run your 4500 inlb load case on our 2003 rear uprights:

.079 deg camber gain from deflection
1.48 lb upright
.28 lb steering arm

As you can see they are made from Brass alloy http://fsae.com/groupee_common/emoticons/icon_wink.gif

http://www.auburn.edu/~pingiii/temp/rearup.jpg

Frank your design looks stiff, any numbers on it? The hub does not look very stiff though, that would concern me.

-Charlie Ping
Auburn University FSAE (http://eng.auburn.edu/organizations/SAE/AUFSAE)
5th Overall Detroit 2003
? Overall Aussie 2003. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Denny Trimble]

Nice! We're looking into manganese-bronze... it makes great propellers, so it's gotta be a good upright material. http://fsae.com/groupee_common/emoticons/icon_wink.gif

University of Washington Formula SAE ('98, '99, '03, '04)

[Ben Beacock]

What's your reason for the brass alloy? I've never worked with it, and just quickly checking it online it seems to be as dense as steel with about the same strength. Is it cheaper or easier to machine?

It looks like Frank's hub may not be aluminum like the upright(in which case it looks strong).

I just spent 3 hours machining aluminum(6061T6) hubs for the 2004 car and only got halfway done 1. http://fsae.com/groupee_common/emoticons/icon_rolleyes.gif Still learning the ropes on the lathe. We're off to a good start considering the only aluminum parts we made last year were rocker arms that never got finished and were way heavy.

Ben Beacock
Co-Manager
2004 Gryphon Racing - University of Guelph (http://www.soe.uoguelph.ca/uogracing)

[clausen]

Charlie, that wheel in the background is seriously cool http://fsae.com/groupee_common/emoticons/icon_smile.gif

Regards

Paul Clausen
Uni of Adelaide

[Frank]

PMSL... Charlie uses brass to counteract Australasian gravitational effects

We're just finishing our lead uprights ATM

stiffness, i delete my FEA studies to remove evidence http://fsae.com/groupee_common/emoticons/icon_smile.gif

Yeah those hubs are steel, flexy ... I claim "not mine"�... the "fingers"� on the hubs are pretty thick though

Um Charlie, are those rod ends in bending (deliberately stirring) http://fsae.com/groupee_common/emoticons/icon_smile.gif

ditto the cool wheels comment

[This message was edited by Frank on November 05, 2003 at 05:46 PM.]

[Charlie]

Thanks for the comments, yes the wheel looks pretty good, it is custom brass alloy too. http://fsae.com/groupee_common/emoticons/icon_wink.gif I highly recommend it to all the top teams. http://fsae.com/groupee_common/emoticons/icon_razz.gif We got them done just for FSAE-A like Frank said.

Frank, you are right the upper rod ends are technically in bending, but the bending force is very small. The lower a-arm has a spherical bearing.

-Charlie Ping
Auburn University FSAE (http://eng.auburn.edu/organizations/SAE/AUFSAE)
5th Overall Detroit 2003
? Overall Aussie 2003. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Brent Howard]

hmmm, charlies uprights look alot more like gold anodized Al to me....but that's just me. We run keizer wheels that look just like that wheel in the background too with some black anodized hubs. Just wondering though if the 1.46 lb number includes all that upper mount and the bolts you have connecting the upper control arm and steering rod?? I weighed ours today and they are about 1 lb higher than your number, but they are welded steel plate, so a weight increase is expected.

Brent

www.ucalgary.ca/fsae (http://www.ucalgary.ca/fsae)

[Frank]

Charlie, surely those weights are in stones not pounds, or am getting those funny american units wrong again?

regards

Frank

[Jakub]

Hi,

I was just wondering what kind of fatigue analysis do people do on their uprights? Just keep under the endurance limit of the material, or actually work out what the life expectancy is?

Jakub
UNSW FSAE

[Charlie]

Yes, the weights are in lbs. I listed the toe arm and upright seperately if you look at the post again. It does not include bolts or camber shims, those should add close to .2 lbs to the total.

-Charlie Ping
Auburn University FSAE (http://eng.auburn.edu/organizations/SAE/AUFSAE)
5th Overall Detroit 2003
? Overall Aussie 2003. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[LukeT]

Hey Charlie, your A-arms look to be steel, any reason you're not using aluminum?

-Luke Thompson
Vandals Racing 2003-04
University of Idaho

[Brent Howard]

Sorry Charlie,

I realized that you had posted that after I had posted, but the .28 lbs seemed light for the entire steel section + bolts + shims so I wanted to get clarification of what exactly you were weighing.

Brent

www.ucalgary.ca/fsae (http://www.ucalgary.ca/fsae)

[Big Daddy]

Charlie,


I am just interested in how you fit that inside of a wheel it seems to be quite large. If you have a pic that would help.

Also why do most teams make thier own uprights when the ones off an atv are plenty strong enough and end up being about the same weight? Any insight would be apperciated. The only reason I can see is maybe improving the load paths but atv spindels can more than hadle 1.7 g's.

"A woman is a lot like a beer, they look good, smell good, and you would run over your own mother to get one." Homer Simpson

Nobody is born with a steering wheel or a gear shift in his hand. It's something you choose to do or you don't.
Mario Andretti (1977)

[Charlie]

A picture would show the same upright inside a wheel. http://fsae.com/groupee_common/emoticons/icon_confused.gif Surely you can draw a circle around it and figure it out?

If you design your suspension and find an ATV upright fits the criteria you need, go for it. 'Plenty strong enough' was certainly not our only concern.

-Charlie Ping
Auburn University FSAE (http://eng.auburn.edu/organizations/SAE/AUFSAE)
5th Overall Detroit 2003
? Overall Aussie 2003. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Big Daddy]

My point was that it is hard to judge size if there is no reference. What other design criteria is there. Strenght should be the only criteria who cares what it looks like as long as it lasts the race. If it translates the load correctly and holds up then what else is there????

"A woman is a lot like a beer, they look good, smell good, and you would run over your own mother to get one." Homer Simpson

Nobody is born with a steering wheel or a gear shift in his hand. It's something you choose to do or you don't.
Mario Andretti (1977)

[Denny Trimble]

Well, we were discussing stiffness. You could make your upright look like a vertical leaf spring, and it might not fail, but you might gain 2 degrees of positive camber during normal driving.

If you care about camber and toe control, you'll consider stiffness in designing your suspension system, not just strength.

Also, custom suspension points are a good reason to make your own uprights. You won't win any points in Detroit telling the judges "well, the roll center is 2" higher than I wanted but we didn't have to make our own uprights".

University of Washington Formula SAE ('98, '99, '03, '04)

[Brent Howard]

Also, with using ATV uprights you are limited as far as hub design, rotor design, and caliper choice as all of these are significantly affected by your uprights. It would be very difficult to convince the judges that your brake system is the same as an ATV's because you decided to use ATV uprights and that this system is applicable to an FSAE vehicle.

Brent

www.ucalgary.ca/fsae (http://www.ucalgary.ca/fsae)

[Big Daddy]

True about the roll center but I was taking stiffness in to acount with strength. What if you design calls for a high roll center? I know it wouldn't be a typical car but then that is the reason for some of my designs to make something that looks as though it doesn't belong but preforms like it does. Hope fully when some more construction is done I can post some pics and let the barrage of comments moking it begin but for now I will let your imagination run wild. http://fsae.com/groupee_common/emoticons/icon_wink.gif

"A woman is a lot like a beer, they look good, smell good, and you would run over your own mother to get one." Homer Simpson

Nobody is born with a steering wheel or a gear shift in his hand. It's something you choose to do or you don't.
Mario Andretti (1977)

[Charlie]

Sounds to me like you have already decided to use ATV uprights, without valid reasoning, and are now trying to convince yourself. What is your weight, and stiffness. You are saying that they are comparable, so obviously you've done some analysis?

-Charlie Ping
Auburn University FSAE (http://eng.auburn.edu/organizations/SAE/AUFSAE)
5th Overall Detroit 2003
? Overall Aussie 2003. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Big Daddy]

nothing but first had experience using them for about 4 years and seeing the abuse they hold up to like end over end rolls down hills with a 500 lb quad with no deformation that is enough for me because by the time you analyse and cnc out your ally ones mine are done and on the car for testing about a month ahead of yours. Just something to think about. I agree that analysis is very important but choose your battles.
Also I have seen teams that have analysed thier uprights and still yet they have bent durning either the comp or before the comp. With ally uprights you still Have to have a steel spindle so why deal with two materials when quads are already steal to begin with.

"A woman is a lot like a beer, they look good, smell good, and you would run over your own mother to get one." Homer Simpson

Nobody is born with a steering wheel or a gear shift in his hand. It's something you choose to do or you don't.
Mario Andretti (1977)

[Alejandro]

Hi Big daddy.
The fact that you buy your uprights doesnt mean necessarily that you will be testing your car before the one´s that doesn´t. There are Universities that build(for example)their own calipers.. mufflers..master cylinders..and others that buy it. So the time that a team has for testing is the one that they schedule. So testing early is not a good argument for using ATV uprights. But as you said, we choose the battle.

Alejandro Rondon
Universidad Simon Bolivar
www.formulasae.grupos.usb.ve (http://www.formulasae.grupos.usb.ve)

[Frank]

if you use steel,

you're using either

stressed skin design

or

thin walled sections (tube, rhs)

the choice is either use steel like this, and battle with welding, distortion, accuracy

or use ally billet, and battle with machining a large billet into a relatively thin walled section with a fair amount of detail

the only other way is casting, and i doubt many teams do that, mainly due to lack of resources, and that the cast shape would be IMO difficult to cast, and most likely heavier

as for OEM items, yeah sure great idea, but the likelyhood of finding a decent geometry that suits, that is in the ballpark of competitive weight is, IMO, slim

the only other thing to remember is that if you are competing "down under" this year, you should use LARGE and HEAVY billets of brass or lead to increase "download" on the wheel., and counteract the inverse gravitational effects experienced south of the equator

http://fsae.com/groupee_common/emoticons/icon_smile.gif

Frank

[Charlie]

Franks absolutely right; as I mentioned awhile back, unsprung weight is a lot more important in Australia, hence why tyres are filled with water (unlike tires which we fill with air)

-Charlie Ping
Auburn University FSAE (http://eng.auburn.edu/organizations/SAE/AUFSAE)
5th Overall Detroit 2003
? Overall Aussie 2003. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Frank]

"hence why tyres are filled with water (unlike tires which we fill with air)"

PMSL

I think you're onto something Charlie

[A Reinke]

off last years car:

rear: http://aod.no-ip.com/images/fsae/img%20044.jpg

front: http://aod.no-ip.com/images/fsae/img%20043.jpg

[chinesefonz]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by A Reinke:
off last years car:

rear: http://aod.no-ip.com/images/fsae/img%20044.jpg

front: http://aod.no-ip.com/images/fsae/img%20043.jpg<HR></BLOCKQUOTE>

so is that steel in the front and ally in the rear?

[Brent Howard]

Look like cast Aluminum fronts and machined billet rears to me.

Brent

www.ucalgary.ca/fsae (http://www.ucalgary.ca/fsae)

[Denny Trimble]

I'd watch that lower front a-arm... that's about twice as ugly as ours was before it failed. See the "fatigue testing" thread.

University of Washington Formula SAE ('98, '99, '03, '04)

[A Reinke]

both uprights are machined aluminum. obviously if we were making more then just four, we'd cast them.

i will look for your thread UoW...we actually had problems with those rod ends shearing... http://fsae.com/groupee_common/emoticons/icon_frown.gif

~Adam

[Brent Howard]

What are the fronts coated with then? You can't see any machining marks.

Brent

www.ucalgary.ca/fsae (http://www.ucalgary.ca/fsae)

[MercerFSAE C. Burch]

For those of you running 13" wheels, what is the spacing between your upright a-arm pick-up points? I'm toying with a 10" (vertical) spacing, but I'm wondering if that will limit my turning radius too much at the front. Also, I might be unknowingly forcing my a-arms to undergo too much force since the spacing on the chassis between points (horizontally) is just 10". My kpi is nearly 0 deg, with perhaps a 1" scrub radius. I will post Pro/E pix soon.

-Chris

[MercerFSAE C. Burch]

Here is a picture:

http://www.angelfire.com/ga3/auto4sale/frontleft.JPG

Any ideas?

-Chris

[René]

Hey Cris, I have a little more thant that between the vertical a-arm pick-up points. The thing is how much do you want your wheel to turn. I'm using at least 33?. 10" horizontaly should hold on but you must prove it and run a load simulation. Kpi and scrub are ok, try to keep those numbers in that range.

PD Man, out of curiosity, you should have had all those points long time ago. Are you bulding a chassis without the definitive suspension points?. I guess not.

Anyway, greetings

René
División de Suspensión
Equipo F-SAE USB
http://www.formulasae.grupos.usb.ve/

[MercerFSAE C. Burch]

We've had those points since June, but I never really checked with any of the other teams for the "experience" design factor. We haven't built anything yet. We're CAD'ing the whole car to make sure that all our pieces fit together before we start building and it is taking some time.

More car CAD (http://www.angelfire.com/ga3/auto4sale/fsae/team_files/july7pix/index2.html)

-Chris

[This message was edited by MercerFSAE C. Burch on November 14, 2003 at 02:02 PM.]

[Lyn Labahn UW-Madison]

Chris,

Just an FYI, your frame does not meet rules right now because you are missing the proper front bulkhead size (1inch .065) and support structure. Maybe you already know this, but I thought I would pass it along.

[Alejandro]

chris, are you using Billet racing wheels? Hw much do they weight? they must be very light because of the price..hehe

Alejandro Rondon
Universidad Simon Bolivar
www.formulasae.grupos.usb.ve (http://www.formulasae.grupos.usb.ve)

[MercerFSAE C. Burch]

Well, I'm not actually the chassis person, but yes we are aware of the rules. The wheels are there mainly to fill up space and help get an idea of where everything is. The drawings you see are mainly to get the layout of everything where we want it. Actuall designed parts are being drawn up and put in assemblies. The shock is the right size (Risse Racing Rupiter 5R from the drawing they sent me). Since Pro/E occasionally has geometry tolerance issues with large amounts of pipe objects put together in one part (the frame) the chassis is just a bunch of solid members of various diameters, not necessarily conforming to the rules.

-Chris

[nivlacoey]

Hi, I am new in designing of the upright and now I am doing some research on the upright design. However, I can't find much info on the web. Are there any recommendations on website or books which I can look up on the designing of upright?

[Jersey Tom]

Your Materials Science, Solid Mechanics, CAD, and Design classes should be all you need.

Find some pictures from competitions, or take pictures at competition when you go out there, if you want starting-point ideas.