Keegan's Kiddie Kart

[Keegan]

Thanks guys! It's going a lot slower than I would have liked, but my hope is to have it done before March.

 

[DaiSan76]

Did you use any sort of bearing in your A-Arm assembly, or just bolts?

 

[Keegan]

I made my own polyurethane bushings.

 

[DaiSan76]

That is cool. I wonder how long they will last.

 

[Keegan]

I expect they should last nearly the life of the cart. Polyurethane is quite common in bushings for automotive purposes both OEM and after market parts. The material I'm using has the same basic properties (hardness and elongation ect) as those products. Also, these bushings will never see the load bearing weights that the automotive products see. I'm sure I'll have to grease them from time to time, but you would have to do that with virtually anything you use as a bushing.

 

[DaiSan76]

Where did you buy it? I like that idea. I assume you bought a solid bar of it and then cut and drilled it?

http://www.usplastic.com/catalog/item.aspx?itemid=34006

This look like a decent price to you?

 

[Keegan]

I actually made them from scratch. One of the main services that my business provides is sprayed polyurethane/polyurea coatings and linings, such as you would find in the back of a pick-up truck.

I cast a block of polyurethane and then used a 1 inch hole saw (which is almost exactly perfect for 1x14ga tubing) to cut out the bushings. Nice thing about the whole saw is that it perfectly centers and drills the hole in the middle of the bushing. Then I just used a 3/8 bit to size the center hole for the mounting hardware.

I can also cast the material directly into steel tubing using it as a mold. Then you'd have to perfectly drill the center hole, which is a lot harder than it sounds.

 

[Keegan]

The front arm mounts are finished. Got my first look with both front tires mounted. I made the mounting plates for the air shock. Tonight I'll order the rod ends to make the pivots and pushrods.

I'm thinking of taking a trip to the junk yard tomorrow to grab a manual steering rack.

Has anyone used a Geo Metro manual rack? They've got 6-7 Geo Metro cars up at my U-Pull yard. I figure they can't get much smaller than that.

 

[j.concepcion54321]

oh man, dude you make things look soo undercomplicated. kudos to you man, great kart build.

 

[theo]

Keegan, can you tell me what those air shock from, and what is the measurement eye to eye extended? thanks.

 

[Keegan]

Monroe max air #ma768. 18.5 inches extended. Here's the mounting and length sheet for Monroe. Air shocks are on page 20. Page 5 explains mounting and hardware.

http://www.monroe.com/assets/downloads/english/08_MountingLengthSheet.pdf

 

[theo]

Thanks Keegan, are you using them all around.

 

[Keegan]

Just the front for now. No rear suspension yet.

 

[Keegan]

Geo Metro Rack and Pinion

Went to the junk yard this morning. After searching the lot, I decided on a rack and pinion in a Geo Metro. Removal wasn't too bad and the price was right at $21.

It's clearly too long right now, but I'm going to try and fix that in the next few days.

I started working on it by cleaning it up and tearing it apart. It was much easier than I thought it would be.

Now I should be able to take some measurements and start cutting it up.

 

[Keegan]

After the blast cabnet

 

[r97]

Whats going on with the front suspension before? I'm guessing your going to basically have one shock work for both wheels?

I have never seen that before, I can think of a few ways it might not work to well, but it would be cool if you could get it to work!

 

[Keegan]

Whats going on with the front suspension before? I'm guessing your going to basically have one shock work for both wheels?

I have never seen that before, I can think of a few ways it might not work to well, but it would be cool if you could get it to work!

Yeah it's a single spring for the front end. Time will tell if it was a bad idea. Remember this isn't going to enter the Baja 1000 so I don't have high performance expectations.

 

[r97]

Yeah, as long as it soaks up the bumps good enough it is fine right? My concern with it is that:

a. The shock is too stiff, so if one side is compressed it will force the other side down instead of compressing the shock.

b. The shock is too light and one wheel hitting a bump would be fine, but both wheels (speed bump?) hitting a bump could cause it to bottom out very easily.

Of course that's just how I'm seeing it in my head now, there is probably a happy medium in there somewhere too.

 

[Keegan]

Thanks Argentina, we'll see if it works.

 

[fowler]

u need to fix the shock in the middle somehow

like R97 is saying the force for one side is transfered to the other

itll be like a solid axle but much worst

as u go into a corner the weight is transfered to the outside and the outside a arms are forced up
your shock system will then transfer that weight to the other side pushing the inside arms down and u will lose all front end control and bottom out or roll