Go Kart Trailer... FINALLY!

[OzFab]

When I purchased a shifter kart rolling chassis a little over a year ago, I realised it wouldn't fit in my 7'x4' box trailer &, my AusEx had less chance because it was even wider so, I started looking fo a suitable trailer & eventually found a small boat trailer with a flat frame (see pics 1 & 2); width = 4', length to peak = 8'6"; when finished, the base will be 4'2"x8' & total length will be 10'6"...

After almost a year, I finally started the necessary mods to turn it into a usable kart trailer which will have the capacity to carry up to 2 karts; apart from the 2" x 2" draw bar, the entire frame is constructed using 1" x 2" SHS, making it really simple to modify...

The first thing I needed to do was establish a rectangle base so, wheel arches off, a trip to the local steel merchant & add a 1" x 2" straight rail down each side... that's when I ran into my first problem...

On the left side, there was around 5/8" clearance between the tyre & the new rail; on the right, there was around 7/8" clearance between the tyre & the original rail...

If I simply move the axle across, I would end up with around 1/4" clearance one each side... not enough for my liking...

I considered stretching the axle in the centre but, once I realised there was a small spring locator plate welded to the axle & that the stub axles weren't straight, I decided to bite the bullet & replace the entire axle, using the original stubs...

Coincidently, I just happen to have a length of pipe exactly the right size...sitting right next to the trailer (that's where it was "stored")

After cutting the stubs from the axle tube, leaving a small length as a base point, I squared off the ends on the lathe, cut one end of the tube square & welded the two together...

Now to trial fit, measure, cut & weld the other end...

 

[Crashz28]

I don't about your neck of the woods but you can buy the spring locator plates pretty cheap or take a cut off wheel and chop them off and move them where you need them!

Other wise awesome project!

I was thinking about swapping out my trailer axle to a axle less setup basicly a hub/spindle on each side. I have a 5x8 enclosed trailer that I have to let the air out of the tires to fit it in the garage.

Just goes to show sometimes if you want something to fit your needs then you gotta build it or modify it yourself!

 

[machinist@large]

Looking good so far. And from the photos, if you keep the current spring height it should sit low enough to be nice and stable.

One trick; to help keep the stub end's parallel, remount the hubs and rim's without the tires. Then, block the rims so they can't spin (a piece of channel iron long enough to support both works great for this) and measure the spacing between the bead flanges in one spot on each side (to account for any variations in the rim's). Place your first tacks; measure. Rotate the axle 180°. Measure. Adjust if needed, place second tacks. Measure.

Now here's where a lot of people get confused: rotate the axle 90° and measure. If it's different, record it but don't do anything yet. Rotate the axle 180° from this position and measure again. If you have any discrepancies, it should be a direct mirror in direction from it's opposite. Adjust, check in all four 90° quadrants. Tack, check again.

This process is to help compensate for any straitness issues in the new axle center section. If the axle stubs (as well as the hub's and bearings) aren't concentric one end to the other, you can build in some really frustrating handling issues without even realizing it. And the reason for mounting the rims is to magnify any potential error so you have an easier time measuring it so you can correct it.

This doesn't require massive amounts of tools, just care, patience, and attention to detail.....

 

[OzFab]

Thanks for the advice, Pat but, too late, axle's done I will check it though, just to see how I did; the stubs were a pretty tight fit in the pipe so, here's hoping it'll be close; however, the way I see it, it has to be better than than the OEMs effort; the deciding factor to replace the axle came when I spun the axle after I split it, with the wheels sitting still, the axle had around 1.5" of runout over 2'... I must be closer than that...

I don't about your neck of the woods but you can buy the spring locator plates pretty cheap or take a cut off wheel and chop them off and move them where you need them!

Already sourced

Other wise awesome project!

Thanks

 

[landuse]

Nice going Tony. Have you got a spot in mind where you can take the karts for a spin?

 

[OzFab]

Umm, no but, I'm still looking; I have a few ideas I need to check out...

 

[Poboy kartman]

Umm, no but, I'm still looking; I have a few ideas I need to check out...

I would look for an open clockwise track with no restrictions..........that way......wait for it.........

It would be "No rules....just right!!!!".......

Sorry.....lame American joke......

 

[OzFab]

AH, so that's why I didn't find it funny

Honestly, I would be happy with a 300M straight stretch of flat bitumen... I'm not fussy...

 

[Poboy kartman]

AH, so that's why I didn't find it funny

Honestly, I would be happy with a 300M straight stretch of flat bitumen... I'm not fussy...

Just to make sure....(you probably know.....but I don't know because you are on another Continen......)

But....they have a restaurant called.....'Outback' here....with a quasi Australian theme....and there slogan is:...."No rules....just right."

 

[OzFab]

The other day I realised the centre crossmember was longer than the rear so, no matter what I did, the frame would never be square; because I couldn't source material to act as a sleeve, I cut down a length of the same material to fit inside, then I cut the rear crossmember in the centre to stretch it by around 10mm (3/8")...

Now, because the corners aren't square, I need to pull the rear crossmember parallel to the centre one & hope it works, otherwise, I've wasted my time & will have to remove & replace it...

Also, here's a pic of the whole thing so far...

 

[OzFab]

A little more work done over the past few days, axle reassembled after cleaning & priming the springs & U bolts, fitted new spacers (they were $5 for the pair) & new fish plates (U bolt anchor plates, $8 each)...

I also manged to fit & tack the header; the bottom piece was notched out around the existing rails to sit under the new side rails...

 

[2SlickNick]

Coming along nicely.

 

[landuse]

I like how you did the notched out metal im pic 6 so that everything fits well

 

[Rickracer]

What I can see of your welding doesn't look too good? Maybe it's the flux core, or stick welding, but I don't see any grinding marks or clean shiny metal where you've cleaned the metal at the joints. If you grind the metal clean, where you plan to weld, the welds will come out MUCH better....

 

[OzFab]

Perhaps not on the centre notches (that piece was in & out 4 or 5 times, which wasn't an easy task so, once it was correct, I just tacked it in place) but, everywhere else is clean &/or is coated with zinc primer... & yes, it's flux core...

 

[Rickracer]

Coated with zinc primer before the weld? Or after? After is fine, before will make it nearly impossible to get a good weld, zinc in the weld puddle is never good....

 

[OzFab]

As a panel beater, I've used weld through zinc primer for years with no adverse effects...

 

[Rickracer]

So this was ground clean and then sprayed with weld through primer?

I'm really not trying to be critical of your work, but I'm concerned that your welds are not going to hold.

 

[OzFab]

So this was ground clean and then sprayed with weld through primer?

Read post #15 again... Either keep up or don't post...

I'm really not trying to be critical of your work

It sure looks that way to me...

Contrary to popular belief, I actually DO know what I'm doing; I don't need your approval...

 

[Rickracer]

Actually, I did read it, twice... not sure what a panel beater is, but I'd guess a body man? Whole different thing than structural welding, but fine, no problem, I meant no harm, and SAID SO, only trying to help, but I promise, you'll not hear from me again on this topic...