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View Full Version : Norschleife das Weston-ring


Cooper "s"
Sep 21, 2007, 6:05 PM
Inspired by Simple-Logic's electric go kart, I decided to build one as well. I have always wanted to build a car, and have done a lot of CAD design on it, but with an estimated cost of 25-30k its way out of my price range right now. So I decided to build a go kart.
I proceeded to Google earth Weston Country Club, where my parents live, and found that its full of GOLF CAR tracks, and so I built my self a track. The picture is not the best, but ill use photoshop later to make it better. I estimate it to be around 3 miles long track. You can faintly see in side the red lines the greyish track. Theres two hairpin turns, a bridge and trees, so it will make for a very good nurbering type track.
http://img210.imageshack.us/img210/9527/westonringfa9.th.jpg (http://img210.imageshack.us/my.php?image=westonringfa9.jpg)

Anyways I got on the track on a bycicle and found out it is not flat there are a bunch up ups and downs on the track... So defenitly suspension will be need to keep my ass on the track and away form the trees. I talked to the members of the SAE team at my school, and they gave me the 2007 cars a-arms, which where just sitting there beginning to rust. Now theres where not designed for my car, so I am going to have to figure out how to make them work, they are very very very very long, but whatever they are already built, so ill take them.
The wheels to be used are going to be 10X7 golf car aluminum wheels, with their "low profile" tires, giving a total dimension of 18x8.75 inches. Plenty of traction, now i just need to figure out if it wont be to hard to turn the steering wheel. I will use an electric motor, looking for a 19-20 hp motor, to overcome the amount of weight of the vehicle plus my ass on there, and use i guess 4 12v batteries. These are the CAD pictures of what i have done so far, I will post the a-arms once I de-rust them and paint them. So far the track length is of 43.76 inches, wheel base of 57.32 inches.
http://img503.imageshack.us/img503/6007/isoyb9.th.jpg (http://img503.imageshack.us/my.php?image=isoyb9.jpg)
http://img146.imageshack.us/img146/86/frontbv0.th.jpg (http://img146.imageshack.us/my.php?image=frontbv0.jpg)
http://img146.imageshack.us/img146/4558/sidehm0.th.jpg (http://img146.imageshack.us/my.php?image=sidehm0.jpg)
http://img227.imageshack.us/img227/8599/topie8.th.jpg (http://img227.imageshack.us/my.php?image=topie8.jpg)

As far as the back goes I really want to use a differential, but it might be to expensive, so I will look into ATV parts, they use rear differentials, with swing axles, so it would be perfect.

I also want on board suspension, but the whole rocker arm calculation for that is just a pain in the ass, and I am lazy, and I would the need to machine rocker arms so we will see.
Also looking at a flat underbody with diffusers, no real reason, just that it looks cool, and race car like. and it will use a 4 point harness and I will put a crumple zone up front I do not want to die, and well a roll bar also. It should be good, Ill keep you guys posted as the progress goes along.

Oh yeah I also already have the two front hubs, just need to design uprights, and build them, and the two front 2 piston wilwood calipers. So it is going along so far.

Hope you guys like it, and once its finished you are all invited to go around the Weston-ring track.

Cooper "s"
Sep 23, 2007, 5:11 AM
Hmm, well I do not know if this is considered double posting, since no one posts, Or if anyone is interested in any updates of the work. So if you guys do not care for the progress just leave a post and I will stop showing the work done on the uber kart.

For those of you who are interested and like the read despite all the spelling errors and my horrible grammar, here we go.

I got to working on the Suspension geometry today. As I had stated before I was really afraid of the length of the a-arms, which where donated. So i used my little crude program to figure out some basic geometry and so far it looks way better than I expected. You can see in the first image the STATIC case of the front suspension. The key features to look at here are the camber gains, which are decent, and where that little black dot is on the center of the geometry. There is not real position for it, but I always liked when my roll center is bellow the ground and this one is. On the second pic we see the dynamic geometry. Since I only wish for a maximum of 1 inch up and 1 inch down of suspension travel, I set the program to simulate this and the results a are great. One can see that the roll center only shifts 0.3 inches. This is great, meaning my car will be able to stay very flat through the curves. You can read the rest of the information on the side, Ignore the spring settings, I have not played with that, and yes the tires look huge, but you cant really change the hight of them on the program, they are just there as a visual.
http://img264.imageshack.us/img264/503/frontstatictb8.jpg
Dynamic case front
http://img483.imageshack.us/img483/3231/frontdynamicmr1.jpg
static case back
http://img487.imageshack.us/img487/5467/backstaticvl3.jpg
dynamic case back
http://img487.imageshack.us/img487/7873/backdynamicrf0.jpg

I'm not too happy with the back, need to figure out the placements of the a-arms still on CAD, still need to define what motor to use, and if I will use a differential, But for now At least I am happy knowing that the suspension geometry is ok and it wont flip the kart.

I started working on the chassis as well, I will post pics as I go of the progress. Hope you all enjoy, and learn a little about the process of vehicle design, which by no means begins with receiving free a-arms but hey.

slezak12
Sep 23, 2007, 6:19 AM
Wow, that is a lot of work you have done there.

If it was me, i would just build something and have fun and not worry about any of that.

But, your doing it the right way!