Like I Need MORE Projects...

[OzFab]

My daughter has a 7yo (almost 8yo) half sister who live here in town with their mother who lost her father last December in a motorcycle crash; this guy supported & raised MY kids for more than 15 years so, now it's payback time...

While discussing our grandkids karts with my ex, she mentioned she would like to get one for her daughter (who's a bit of a speed freak) so, I started looking online & found the perfect kart for her; while searching, I found another which made me think "I'm NOT passing that up!"

So, yesterday (Sunday) I set off on an 8 hour road trip to collect the two; the white kart cost me the same as the fuel needed for the trip ($100) & the black one cost $250 & came with 2 engines; pretty much all the black one needs is the engine & rear sprocket mounted & a chain; the white one needs a little more work, as you can see from the pics...

 

[OzFab]

Pic #1: I think this clutch may be damaged; thoughts?

Pic #2: Clutch & sprocket that came with the black kart; anyone else see an issue?

 

[itsid]

if that's not the pic it's about 1/8" of an issue or say twelve thereof

'sid

 

[mckutzy]

Second on seems good to go... Disassemble and check/clean/re-lube...

Ya..... The first looks a little broken....

 

[landuse]

Nice karts Tony. You should have them going in no time

 

[OzFab]

if that's not the pic it's about 1/8" of an issue or say twelve thereof

'sid

Correct, #35 clutch, #40 sprocket...

Since the clutch on the white kart is... umm... a little worse for wear, I'll use the clutch from the black kart & I have a new #40 clutch on the way; I also have sprockets on the way for a jackshaft...

Second on seems good to go... Disassemble and check/clean/re-lube...

It should be, it's brand new...

 

[OzFab]

Any ideas on permanently connecting two sprockets besides welding? I could weld them but, I don't want to effect the integrity of the sprocket teeth; I thought about roll pins or even drill & tap to insert high tensile bolts; thoughts?

The two sprockets will run internal needle roller bearings on a fixed shaft as a jackshaft as there's nowhere to mount an active J/S...

 

[itsid]

Since I assume you cut the tube yourself to length,
cut another one twice the width of the sprocket longer.

cut the faces of the tube at 45° and 90° one sprocket width deep and cut away the two larger sections on each end (basically converting the tube into some sort of dog clutch.)

cut matching slots in the sprockets.
then either drill and tap small holes per at the shoulder edges of the mating parts to insert a grub screw to locate and fix them in place (right at the seam)
or just solder all together (with some excessive use of flux)
that way you can easily swapp a single sprocket.

downside some excessive filing involved (since IIRC you don't have a milling machine )

'sid

 

[OzFab]

Umm, what?

Sorry Alex, not quite getting that; any chance of you drawing me a picture?

 

[mckutzy]

I'm thinking he's saying make grooves like a lovejoy couplers...

I think however the teeth may be hardend...
A few tacks or a few small welds with immediate cooling.... That won't do much to the heat treat... It'll be fine...

 

[OzFab]

I was thinking the same, it's only the teeth that are hardened, the bush is mild steel which can be drilled &/or machined but, with a 130A 240V welder, it takes time to make a tack long enough to hold yet not transfer heat to the teeth...

 

[itsid]

Umm, what?

Sorry Alex, not quite getting that; any chance of you drawing me a picture?

Yeah I thought this might need an illustrated explanation after I posted it

I'm thinking he's saying make grooves like a lovejoy couplers...

And you are correct

Anyways, I attached a lazy rendering;
I hope it's clear enough

slots in the sprocket are easier to file if you open the bore of course (that much is obvious )
drilled and tapped at the red arrows (again was too lazy to make proper 3d files)
the sprocket should stay firmly attached.



'sid

 

[OzFab]

Ah, I see now; however, these are "B type" sprockets with the bush attached...

You have given me an idea though; if I cross drill & bore the bushes I can press them onto a length of tube & set screw them in place...

 

[mckutzy]

That will do....

 

[bob58o]

Weld or drill/tap/bolt. If bolts can hold a sprocket to a hub, they can hold a sprocket/hub to a sprocket/hub. Insert some rod to center them up and have at it with a drill press.

How thick is the "Bush"?
on the small sprocket? What's the biggest bolt you could use? 4 or 5 bolts should do it?

 

[itsid]

Ah, I see now; however, these are "B type" sprockets with the bush attached...

You have given me an idea though; if I cross drill & bore the bushes I can press them onto a length of tube & set screw them in place...

Oh B-type.. (that difference in colour from the teeth to the collar suggested otherwise in the first pic you attached (at least to me it did)

Sooo.. just like bob said
it's as easy as drilling an offcenter hole through both sprockets and put a bolt through (or just a steel pin)
think of it as makeshift key.

I think two holes and pins/bolts are better than one, but a single one should already suffice mechanically as once lined up the finished pack
shouldn't see much side load if any at all, right?

tap only the "second" sprocket though,
and if you make two holes tap only one per sprocket that way you can put the two bolt heads on opposite sides and the sprockets can still sit perfectly flush with one another.

'sid

 

[OzFab]

The front end of the black kart was built "ok" but, it has issues; when I got them home, I noticed an excessive amount of side "wobble" which usually indicates bad bearings; however pics 1 & 2 show the front stub axles as they were; the plastic sleeve measures around 19mm yet the bearings have an ID of 20mm... no wonder the wheels wobbled...

Also notice the rear spacer flapping in the breeze with a 22mm ID so, I ditched all of that & spun up these neat one piece spacers which provide the correct spacing between the 5/8" stub axle & the 20mm bearing & also provides around 30mm of back spacing to align the castle nut used to secure the wheel with the split pin hole in the axle...

On the white kart, when I first moved it I noticed something amiss with the rear axle; either the sprocket was off centre (nope), the chain was severely stretched (still a possibility) or the axle is bent (BINGO!...

This is gonna be fun because not only are all the wheel bolts corroded in place (steel bolts in aluminium hubs) but, some amateur has welded the brake disc to the axle not to mention the sorry state of the axle in general...

 

[mckutzy]

I reckon it could be a wee bit outa wack.... Hard to tell with all that light shinning through....

 

[ezcome-ezgo]

You have my permission to purchase a new axle.

 

[KingCobra]

I will post photos if you don't mind me sharing my experience. Better yet, I think this is your personal build thread and I better hold off as our carts are as different as explained in the Sesame Street video you are about to watch...I will let bob58o explain this with his favorite cartoon about 'circles' or something like that.. Bring it Bob! Thanx