Starting a suspension Kart

[ed1380]

So I guess I'm getting serious about this, so I've started this log. this is what i have so far.

I'll add more braces to the frame, it just looks weird in CAD.
what about the design for the suspension? are bushing necesarry?
http://i43.photobucket.com/albums/e398/RussianCommy/tri.jpg
http://i43.photobucket.com/albums/e398/RussianCommy/a-arm.jpg

[robertdjung]

what CAD software are you using? Looks like a good project!

You'll need bushings, or bearings, or something if there's play in it. But some material mates up really nicely, and you wouldn't need a bushing. I don't know if there's any materials that are that size that fit together that well, but you might look at some ID and OD size charts.

[ed1380]

solidworks 2007

I'm making the rear suspension now, so more pics later.


I've read of people using pvc with holes drilled to hold grease. good idea?

this is also an area of concern. will it hold up?
http://i43.photobucket.com/albums/e398/RussianCommy/a-arm-1.jpg


where would you recomend adding brases? this is where I thought it would be good, and easy to get in and out
http://i43.photobucket.com/albums/e398/RussianCommy/tri-1.jpg

[AdrianH]

Lovely cad work there, wish I could produce drawings like that.

If you can get hold of the new Haynes book build a sports car on a budget. Why not take a look at the suspension set up on these for ideas.

Use a library if needed to read the book, there was also an older version that may be out of print.

Guess what my new project is!

Go-kart anyone?


Adrian

[ed1380]

here are dimensions http://i43.photobucket.com/albums/e398/RussianCommy/tri-5.jpg

[robertdjung]

solidworks 2007

I've read of people using pvc with holes drilled to hold grease. good idea?

this is also an area of concern. will it hold up?

Where did you read about PVC? Sounds sketchy.

The area in question about holding up: maybe ... matters what the material is, but I think that i'd brace the crap out of it. maybe even some 1/4" plate running down that whole length...

[ed1380]

Heres the rear suspension with braces. I'll add gussets to the braces too.
should I use the same method of bracing up front?
bottom is toward the front or on the Z/blue axis
http://i43.photobucket.com/albums/e398/RussianCommy/top.jpg

here are the dimensions (same as front suspension) should I change them somehow?
http://i43.photobucket.com/albums/e398/RussianCommy/tri2.jpg

[robertdjung]

I think that the beefing up looks better on this one, just matters how hard you're going to punish it.

How did you solve the rear end drivetrain issue, again?

[ryf]

pvc bushings will work...

I've run the PVC without grease fittings(greased every few times a year), if you buy a bolt thats long enough to not have threads on the pvc(chop the ends for apearance if you choose) it should last 2-3 years, mine did on another project... if the pvc sits on the pivot bolt threads, a season of riding perhaps, but it might be sooner depending on how much you ride. when the PVC wears out, it will get sloppy quick and if left unfixed will damage the metal parts. this is the reason most people have bad experiences with them, IMO

You can get urethane bushings online from advance auto parts that will fit into pipe/tubing (using the black water pipe I had to sand the lip on the bushing a little). do a search for universal bushing on their website http://www.partsamerica.com

I'd go to http://www.energysuspension.com/pages/sk_bsp1.html

and choose which one you like (go with the 9.8113 style, they are halves, MUCH EASIER for you looking at your setup) goto advance (partsamerica link) and order them, around $6 a "pair" (2 full bushings, or 4 halves) you might be able to get them ordered at a local store as well

you could also get 9.8107 and cut them in half, that would be less diameter if you need it.

[ed1380]

But some material mates up really nicely, and you wouldn't need a bushing.This is what I'm hoping for, although, finding 13 long bolts might be hard.

I don't know what to do with the short bushings ryf suggested. since the whole thing is 12" long, AFAIK I'd need 12" long bushings


How did you solve the rear end drivetrain issue, again?
What issue?

The only problem I'm having is not knowing what to use for a rear hub. I was thinking of a .25" steel plate with a bearings in the middle for the axle shaft

[ryf]

you could buy any of the ones with a flanged outside edge and cut them in half, then turn down the inside to get the desired diameter (slightly larger than your tube/pipe. the lips on the outside edge will keep them in place. I used 9.8112 and if you leave the lip as is, it will not fit inside 1" black pipe, cutting it as stated, and turning down the middle section into a slight wedge shape will allow it to be hammered or tap into place (leave a flat spot for binding and to make sure it goes straight. tap them witha hammer and a buffer board.

or you could use the two I mentioned that are already large wedges and it will self align (put them on the end of the pipe)

I turned them using a bench grinder and a bolt, wear gloves and let it spin against the wheel, it will go quick so watch and check often. good luck

[ed1380]

so the bushings go where the white parts are?
http://i43.photobucket.com/albums/e398/RussianCommy/top-1.jpg

[ryf]

that would work.

[ed1380]

would it still work if I got rid of the green thing and replaced it with a continuation of the red part. so only 2 bushings are needed per arm. and all force is transfered through the blue braces.

[ed1380]

heres what I was thinking for the rear hub or whatever it's called. (it's yellow)
http://i43.photobucket.com/albums/e398/RussianCommy/tri-2.jpg
http://i43.photobucket.com/albums/e398/RussianCommy/top-2.jpg


@ Robert- would you rather have me upload the pics or hotlink them?

[ed1380]

ok, but what about now.

hotlinking them uses up bandwidth and uploading them uses up server hard drive space. which one do you have more to spare? or none, and i should just post the links.


any thoughts on the rear hubs?

[robertdjung]

uploading them is fine. they get automatically thumbnailed and there's plenty of space.

Are you linking to them now?

about the hub: I still don't understand how you're going to keep the chain from falling off. Maybe i missed a post or something.

[ed1380]

yeah, I'm uploading them to photobucket and them linking them.

I'm gonna have a cv axle or something similar going to the wheels, and the sprocket and caliper are going to be in the middle of the black box. something like this

Now only to know where to get those bearings

http://www.gokartforums.com/images/my_gokart/gokart112.jpg
http://www.gokartforums.com/images/my_gokart/gokart133.jpg
http://www.gokartforums.com/images/my_gokart/gokart92.jpg
http://www.gokartforums.com/images/my_gokart/gokart94.jpg

[2or3wheels]

that thing is the definition of badass, how much has this project put you back in materials minus the tires and motor?

[robertdjung]

that's a nice kart, who's is that?

[ed1380]

that thing is the definition of badass, how much has this project put you back in materials minus the tires and motor?
It's not mine. I just liked it alot and am copying some of it.

that's a nice kart, who's is that?
AFAIK the owner of this (http://www.gokartforums.com/forum/forum_posts.asp?TID=17&PN=4&TPN=1) site, and here (http://www.gokartforums.com/pages/page2.asp) are more pics. just select puma 2.0 from the drop-down menu

[2or3wheels]

Still going to be badass.

[robin]

it looks like he has used 2 flange mount berings back to back.

[ed1380]

I was thinking of using something like this. it's 6-7" long and would work with a 3/4" shaft. is it too long? It would look something like this.

[ed1380]

i made it only 4-5 inches long and it sems too long.
opinions please

[2or3wheels]

Depends on how much travel you want. If you want alot go wide. Plus the wider the more stable.

[ed1380]

so that project is kinda going on hold. I'll still do CAD, but no actual building

heres (http://s43.photobucket.com/albums/e398/RussianCommy/go%20kart/)what i got now. for free

IDK what's the hp, but I do know its a briggs. most likely ohv. How do I find out what the hp is?

whats the weird thing on the carb? is it the choke?

also why is there a lever to adjust the tension of a spring on the governor?

The keyslot on the shaft is damaged. so is the starting mechanism

[ed1380]

update.
I've taken the piston out, cleaned the carb, only thing stopping me, Is I can't take the flywheel off.
I want to take it apart and wash it, cause there is alot of rust inside :confused:

yes it is OHV, and I cleaned the vales a bit (honed?)

awesoem thing is that the carb has a spining effect inside, like chevy's vortec.

[ed1380]

how do i get the flywheel and the broken thing on the shaft off?
heat them up and then knock them off?
http://i43.photobucket.com/albums/e398/RussianCommy/go%20kart/P1020381Medium.jpg

[rocko]

use a gear puller

[robertdjung]

first, take off the recoil starter clutch!!! Stick something in those blades and use a pipe wrench or something to get that last piece off that's in front of the flywheel. Then, use a gear puller, or sometimes you can coax it off with a sharp tap.

[2or3wheels]

That might be a 3 horse because of that recoil set up. At least all the briggs 5 horses i own have the recoil mech in the housing you took off. I used a screw driver and put it on those nubs and used a hammer to get it off. see pic. The to take flywheel off you take off all seperate items then i use heavy duty screwdriver and pry the flywheel off against the block be sure not to pry agaisnt anything that would be ruined, then i lightly tap the shaft with a hammer (if it were a 5 horse with a nut i could make nut flush with whe shft to be sure and not wreck the threads). Usually it will pop right off after a few hits.

[2or3wheels]

Here is the pic.

[ed1380]

well, it turns out that brocken thing just unscrews off. and the flywheel comes off easy.

we have good compression, a killer spark, and the timing looks right, but can't get it to start. (we wrap a strap around the flywheel.)
we use starting fuel, so the carb is out of teh question.

we think someone messed up the timings. (cams)