PDA

View Full Version : Go-Kart suspension upgrade



gda
05-24-2009, 08:42 AM
Upgrading my 16HP kart front suspension to double A-arms and rack steering. Starting with a Yerf-dog front clip from E-bay for under $100 delivered (can't beat it, has a rack and the a-arms).

http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/IMG_0088.jpg

http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/kartsuspension-02.jpg


Cut the flimsy ball joint tabs off (known problem with these karts). Switching over to Heim joints (because I have them).

http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/kartsuspension-03.jpg

Made thread bungs, and used the right angle head to cut a hole for them. Offset the top bungs from center to add some caster.

http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/kartsuspension-06.jpg

gda
05-24-2009, 08:43 AM
Try making this hole with a drill or hole saw!

http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/kartsuspension-08.jpg

Also teaching myself to Tig weld.

http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/kartsuspension-11.jpg

http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/kartsuspension-10.jpg

Made some progress on making the spindles today. I'll wait until I mount the clip before I make the tabs for the steering so that I get the ackerman angle correct.

http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/suspension-1.jpg

gda
05-24-2009, 08:44 AM
http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/suspension-3.jpg

http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/suspension-4.jpg

welded the front clip on last weekend, set up the steering, and finished the spindles this weekend. I managed to line up the clip to use the existing top shock mount positions. This will help to direct the load straight to the frame (clip has shock mount tabs also)

Figuring out the spindles was tough to allow them to clear everything while maintaining ackerman angle and steering link parallelism with the A-arms (and not look hacked up). They turned into quite the works of art. They are made from 3/8" plate, a 1"X 2" rectangle tube, some 1.25" diameter bar stock, and some 5/8"-11 x 6" grade 8 bolts. I MIG welded them with a welder set up for sheet metal with 0.023" wire, so they are not the best, but will pass.

http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/spindle-01.jpg

http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/spindle-02.jpg

gda
05-24-2009, 08:45 AM
http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/spindle-09.jpg

http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/spindle-06.jpg

http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/spindle-08.jpg

gda
05-24-2009, 08:46 AM
I managed to finish the upgrade this morning - final welds and then paint since it was warm. Fully assembled and aligned by eye for the maiden voyage. It works great! No tire scuff and the steering is smooth. Original steering was through two loose bell cranks and was touchy and dangerous, Single arm also had bump steer and terrible camber going over bumps. (see top picture at start of post).

Well worth the upgrade. I now see the supsension moving but do not feel it in the steering wheel or the handling of the kart.

http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/suspension2-1.jpg

http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/suspension2-2.jpg

http://i222.photobucket.com/albums/dd48/tool_collector/kart%20suspension/suspension2-6.jpg

andy_b
05-24-2009, 08:56 AM
NICE!!!!!!

that came out great! when are you going to post an action video to YouTube? :)

andy b.

Dawai
05-24-2009, 10:20 AM
Great... I helped with a 4 wheeler to cart conversion a few years back.. It had a XS650 yamaha engine. THE rocks coming off the rear wheels would send you to the emergency room. Fenders are needed sometimes.

I saw a hayabusa on ebay a bit back.. wrecked.. make a good engine upgrade..

http://www.youtube.com/watch?v=z6JQv2MCq8c
Hate to agg you onto bigger things.. but.. check this video out. You are not too far out from building one of these..

japcas
05-24-2009, 10:30 AM
That looks great. Thanks for sharing and good job taking pictures for the post. If we all took pictures of our projects like this there would be no end to the list of neat projects posted on this forum.

gda
05-24-2009, 10:33 AM
DAVID: I'm actually slowly collecting parts for a bigger buggy - That yellow one is just something to tinker with.

For my buggy I already have a running Suzuki Katana 750 bike, a torsen differnetial, Porsche halfshafts, seats, covers, steering wheel, 5 point harneses, a rack, and some other bits. I don't have the space to build it right now (or a place to ride either) so I'm not pushing that project.

mochinist
05-24-2009, 10:36 AM
Very cool upgrade and nice work

retusaf99
05-24-2009, 10:44 AM
Holy crap!! Once in a while you see a project that screams coolness!!

I'm fairly certain that this is what we will end up driving when the new CAFE (Corporate Auto Fuel Efficiency??) standards are in place.

Hmmm...35.5mpg, no problem. 0-60mph, 14.8 nanoseconds...

I like it, a lot!!

Doug

Dawai
05-24-2009, 10:59 AM
Hint:
Put street tires on it.

I got this 23 t-bucket frame I built.. weighs 113lbs.. Of course I was gave a 1964 327 for it last week.. and.. (add 480lbs for engine, 350auto add 200lbs.. rear axle, add 300lbs.. tires, add.. radiator, add.. C-cab body.. add another 200lbs..

Still 300hp easy.. should rev like a electric motor, and 1600lbs max.. You want a auto cause you ain't got time to shift..

If you used a 23 fiberglass body.. guess what?? it'd register as a 23 "custom car" regardless of engine type.. A fun gocart that will flatten your eyeballs.. I took a ride on a Ranger-4wd rail w/460 engine hooked to that driveline.. OMG.. I liked to have gotten sick it was so much fun.. I was so pumped with adrenalin it took hours to come down.

Kerry's roadster.. Cut down here.. not bodied yet.
http://www.youtube.com/watch?v=dOpVFVROcIY
Shave weight=more fun.. smaller engine means less driveline needed..

You seen Adian's psycho cart over on www.metalillness.com (http://bbs.homeshopmachinist.net/www.metalillness.com)

There is a nut local here with a banshee with nitrous-turbo installed. He kinda favors a girl I dated about twenty years ago..

I love toys.. I think they keep you young..

JS
05-24-2009, 11:16 AM
....nice job

usn ret
05-24-2009, 11:44 PM
gda. nice work, welding is better than beginners work, process and engineering is well thought out with outstanding end results. However, the fasteners in the pivot points could use some more thought. Threads appear to be riding on the pivot area, and elastic lock nuts need to extend completely thru the elastic lock, longer bolts are in order or the next step up is hardened sholder bolts with steel locking nuts. I used to inspect airplanes in a past life.
Cliff

torker
05-24-2009, 11:57 PM
Nice work but watch the undercut you have with them tig welds.
You need to hold your tungsten closer and let the metal flow around it. Yer arc length is too long and it's causing the undercut.
Try to keep the arc inside the bead width a little more. SLOW DOWN...

lugnut
05-25-2009, 12:25 AM
Nice job, have a lot of fun.
Mel

michael3fingers
05-25-2009, 12:53 AM
well done mate.. you made it look so easy.

trap
05-25-2009, 03:44 AM
Neat work. Heim ends will sometimes pop apart.
Suggest putting large safety washers on at least one side of them.

gda
05-25-2009, 10:50 AM
Thanks guys for looking so close to the details:

Torker: Thanks for the tips, This was the hardest thing I welded so far (2 different thicknesses around a tube joint). I used a 3/32 tungsten and a gas lense so I could get more stick-out. I did see the undercut after I did it, but I thought it was from too much heat. I'm a little confused now - I thought shorter arc gave more amps = hotter, but with a constant current supply does it matter that much (within reason)?

USN RET: No argument. The bolts got too short when I doubled the thickness of the 1/16" tabs that the inner pivots mount to (because I've seen pictures of these ripped out when people have crashed). If you look at unpainted pictures you can see the tabs I added. Basically what was silver was what I started with (Yerf Dog Spiderbox front clip). The design is piss poor on these cheap kart parts - as you noticed they have bearing areas on threads - and as you would imagine the thread in that area is bashed. Right now I cross drilled the nut and wired it. To fix it correctly I'll have to make my own shafts. The a-arms have bushing in them and they are supposed to take the relative movement - with the bold fixed and the tabs only providing location. I'll make my new shafts and weld a tab on the frame that will sit against one of the flats on the bolt hex to ensure that it is stationary and not spinning.

Trap: Thanks for the washer suggestion - good idea, i'll do it. These heim joints are actually left hand thread - why - because that is what I had and got for free!

J. Randall
05-25-2009, 03:54 PM
Good job, looks an awful lot like one a guy showed over on the metal illness site 2 or 3 months ago.
James

gda
05-25-2009, 05:13 PM
Yes that is me on the metal illness site as well (same name as well) - I have more posts there but posting links from one BB to another BB is typically frowed upon by the moderators so I have just been starting becoming active here and transfering posts here because there is a bigger audience.

Teenage_Machinist
05-25-2009, 05:20 PM
Most impressive!

torker
05-25-2009, 05:54 PM
Thanks guys for looking so close to the details:

Torker: Thanks for the tips, This was the hardest thing I welded so far (2 different thicknesses around a tube joint). I used a 3/32 tungsten and a gas lense so I could get more stick-out. I did see the undercut after I did it, but I thought it was from too much heat. I'm a little confused now - I thought shorter arc gave more amps = hotter, but with a constant current supply does it matter that much (within reason)?

I wrote this up over on the welding section. Prolly a good thing for everyone who is learning to tig to read...
http://bbs.homeshopmachinist.net/showthread.php?p=444127#post444127
Russ