All-Wheel-Drive Go-Kart!

[joshpit2003]

I'd decrease the travel of the shocks... there really is no point in having the control arms travel higher than the position of the go-cart frame itself, unless you're going to be running really huge tires or something. still... seems like way too much suspension travel.

 

[Smurph]

I'd decrease the travel of the shocks... there really is no point in having the control arms travel higher than the position of the go-cart frame itself, unless you're going to be running really huge tires or something. still... seems like way too much suspension travel.

The scale is still a little off. The travel of that shock is actually close (within 2 inches) of the real travel. I'll decrease the travel by widening the kart (longer control arms). My tires will always be the lowest point

 

[joshpit2003]

keep in mind longer control arms means a longer lever arm for applying force (meaning you will need to beef 'em up a lot, epspecially wherever you attach the coil-over).
another thing to think of:
Since you are on a budget maybe using some craftsman u-joints for sockets would work? just a thought and it could be a dumb idea, but I would think that they are more than capable.

I know that I purchased some joints for 30 bucks ea. and I thought they looked almost identical to a 1/2 craftsman u-joint socket drive. (they even come w/ torque ratings. haha)

 

[Doc Sprocket]

Socket U-joints for the driveline? No, you don't want to do that. They don't have bearings or any real lubrication engineered in. Not something you want to use for a high-speed application. You probably safely use 1/2" socket univerals in a steering shaft, though.

 

[joshpit2003]

yeah, that makes sense.
but i dont think any of those come with actuall ball-bearings if thats what you're thinking. They may come with machined brass for a bearing, but still no moving bearings. good call using them for the steering shaft though... that will save you 50 bucks.

 

[joshpit2003]

anyone know of a good place to get bevel gears? or spiral bevel gears?
(basically I need a ring and pinion, but dont want something out of a cars differential)

 

[joshpit2003]

i ask because you could potentially fab a ring gear to fit where the sproket is meant to go on a go-cart diff. that would allow you to go shaft drive if you were still thinking about it.

 

[Smurph]

anyone know of a good place to get bevel gears? or spiral bevel gears?
(basically I need a ring and pinion, but dont want something out of a cars differential)

I've looked and looked. This is the closest I've come. I really wish they were more available. And if anyone has a better link, it would help me as well.

I did buy that mopar differential for $30 shipped. The only reason I haven't just sold it (because its just too effing massive) is because the gears inside would work for something. I have a few ideas in mind.

i ask because you could potentially fab a ring gear to fit where the sproket is meant to go on a go-cart diff. that would allow you to go shaft drive if you were still thinking about it.

Look a couple pages back, I thought of a way to use two bevel gears and a small chain to do that. The problem is that I don't really wanna change the ratio at that point, and most [all that I've found] ring/pinion gear setups do.

 

[joshpit2003]

yeah... automotive gears would be too heavy and total overkill for what I'm doing (and also what you're doing).

I actually like the idea of being able to gear down at the ring and pinion (or bevel gears).

I'm still looking for a good site to get a ring and pinion (or spiral bevel gears)...maybe a place that sells 'em for an ATV or something... the problem is that it's almost impossible to find 'em sold outside of the differential they come in.

I'm still searching and I'll let you know if I find anything.

 

[joshpit2003]

Ok, so here is what I have found so far:

http://pdf.directindustry.com/pdf/the-hilliard-corporation/auto-lok-differential/29728-19456.html

Page 1,2,and 3 show the "Auto-Lok" differential which looks like it comes with a sprocket.
Page 4 shows a "Front Drive System Differential" which is a complete ring and pinion assembly.

I have requested a price quote and will get back to you on that when it comes in.

HERE IS MY PROBLEM:
If you read the descriptions of these differentials you will find that they appear almost too good to be true and i find that the information almost contradicts itself in the descriptions.
Maybe I'm wrong and my guess is correct, but please... if someone knows how these work, inform me. (thanks)

I have a guess as to how these differentials work:
(lets forget about 4wd for now and concentrate on just one axle)

From the descriptions you will see that the inner wheel is the only wheel powered in a turn, and after straightening out it claims both wheels are under power. I would guess this to mean that there is a clutch or ratchet of some kind that allows either of the wheels to "get ahead" of the other durring a turn...in other words, one of the wheels is rolling faster than the driveshaft is saying it should.

if thats how it works (bear with me now):
One wheel is allowed to spin ahead of the wheel under power, then that means this may be the answer to our problems. I would guess this to mean that so long as both wheels are turning at the same (power output) speed they are locked together... one wheel NEVER spinning less than the power output.

I would guess you could:

1. drift corners spinning both wheels (assuming you have enough power to break the traction)
2. drive with all the power even when one wheel is lifted off the ground.
3. make sharp turns without tire scuffing (only if your inside tire is capable of pushing the vehicle through the turn).

If my guess is correct then I can only see one problem (which isn't such a big problem for my application):
If you were to try and make a sharp turn with ONLY the inner wheel powered, it requires that your tire have enough traction and power to push your vehicle through the turn... and if you could imagine a very sharp turn being powered only by the inner wheel, you will start to see why that will become a problem. What whould most likely happen in a sharp turn w/ little traction is that inner wheel (under power) will slip and catch up to the same speed as the outer wheel (coasting) and the power will be applied to both wheels (inner wheel now slipping and outer wheel propelling the vehicle)... the bummer is that for the time it takes the inner wheel to catch up to speed with the outter wheel is the amount of time you are essentially (screwed) with an "open" diff.

this seems to make sense in my head, please let me know if this sounds correct.
-josh

 

[Kaptain Krunch]

I think you should just start building, theres been an awful lot of drawings, but have you even touched the welder yet?

Have you decided on a powerplant?

 

[porsche930dude]

I think you should just start building, theres been an awful lot of drawings, but have you even touched the welder yet?

Have you decided on a powerplant?

hell yea. Iv never drawn up a plan on anything iv ever built from scratch. Its more better to do it on the fly. And as you go your going to see that changes need to be made anyway.
making your own differential is probrobly going to be bad i can see that breaking constantly and causing much frustration in general. Have you considerd shaft drive motorcycle parts?

 

[Smurph]

hell yea. Iv never drawn up a plan on anything iv ever built from scratch. Its more better to do it on the fly. And as you go your going to see that changes need to be made anyway.
making your own differential is probrobly going to be bad i can see that breaking constantly and causing much frustration in general. Have you considerd shaft drive motorcycle parts?

Yeah,I'm an engineer, and already have the applications available, and am used to the protocol to fully plan before building. It's a great idea if you're an efficiency expert.

However, I do not have the dang welder yet. Still haven't gotten ahold of that. My financial freeze just ended today, in fact. Got the taxes done, know where the money's going again. Next on the list is the welder.

As far as the power plant goes. I've still not found one. I wasted some time on a few leads on craigslist. Drove 30 miles for disappointment because the engine looked nothing like the images he sent.

I'm still on the lookout. I want a 4-wheeler engine for reverse purposes. But I'd take a bike engine as well. I'd like to put a bigger engine on it. 400-500cc 4-stroke would be cool. 250+cc 2 stroke might work, too.



As far that page/link goes, I would LOVE to find some of those limited slip differentials, or the drive system. The electronic control for the locking could be easily powered by a PLC and a couple other components could control it. That's definitely gonna cost some cash, so that's another day.

But the limited slip differential really peaked my interests.

 

[joshpit2003]

awesome. I'll let you know what quote I get back.

I'd suggest you take some welding classes if you haven't already.
I'd also suggest you buy your welder used and buy the most expensive one you can afford. (dont even think about going to Harbor Freight...they do have very helpful 90 degree triangle magnets though...)

I have a syncowave200 tig welder and I can tell you with confidence that is a great machine. You can pick up an older one (syncrowave 180?) for about 1000-1500 bucks or so.

 

[Smurph]

awesome. I'll let you know what quote I get back.

I'd suggest you take some welding classes if you haven't already.
I'd also suggest you buy your welder used and buy the most expensive one you can afford. (dont even think about going to Harbor Freight...they do have very helpful 90 degree triangle magnets though...)

I have a syncowave200 tig welder and I can tell you with confidence that is a great machine. You can pick up an older one (syncrowave 180?) for about 1000-1500 bucks or so.

My dad is a really good welder. He's gonna be my welding teacher.

I also used to work for T.J. Snow. A company that designed resistance welding robots. Large machines sometimes. It was a cool company, they go from concept to completion under the same roof. They have a private jet, and will fly to your location in North America to perform maintenance on your machine.

 

[KartRacer695]

thats gonna be really difficult unless you have the time and money, i would go with a 4x4 quad drive train.

 

[Smurph]

thats gonna be really difficult unless you have the time and money, i would go with a 4x4 quad drive train.

I've got a lot of time on my hands. I'm doing this for the build rather than for the kart, tbh. I'm just an engineer trying to challenge myself. A bada$$ kart will just be the icing on the cake.

 

[joshpit2003]

Ok.

http://www.hilliardcorp.com/drivetrain-clutch.html

The Auto-Lok sprocket drive is what I think you will want.
You can actually find them from a variety of suppliers...it is mostly used for lawn mowers and other yard equiptment. I think it would work great for your aplication. Expect to pay 60-100 bucks each. The only thing that concerns me about this one is whether or not it would hold up to the HP you plan on giving it. other than that I think this would be a great diff.

The larger "auto-lock" that is pictured in one of the pdfs is for automotive use...it acts as a replacement for spider gears so it wouldn't work as a stand-alone diff.

The "front locking diff" seems to be an awesome idea. I talked with somone at Hilliard about this one and he confirmed everything awesome about it. The bummer about this one is that it requires a 12V power supply, but that 12 v power supply allows you to turn on and off the axles... meaning you could chose w/ the click of a button between 2wd and 4wd. These diffs also freewheel, so you will have to rely entirely on brakes to stop the cart and you couldn't engine brake. (you could engine brake w/ the sprocket-type auto-lok mentioned above). Expect to pay approx 250-300 bucks a unit for these bad boys.

hope that helps. it seems like you can get a killer set up for relatively cheap if you decide to go chain drive. If you are going shaft drive (like me) then I think it may be worth the extra $ for that front diff mentioned above.

 

[joshpit2003]

this is also assuming that locking diffs are in your interest. If you are just going w/ opens then I think one of the diffs. from the motorized wheelbarrow would work. those are 140 bucks each or you could get the smaller axled ones (for trikes) for 100 bucks each.
The link is a page back... porschedude posted it.

 

[Smurph]

Ok.

http://www.hilliardcorp.com/drivetrain-clutch.html

The Auto-Lok sprocket drive is what I think you will want.
You can actually find them from a variety of suppliers...it is mostly used for lawn mowers and other yard equiptment. I think it would work great for your aplication. Expect to pay 60-100 bucks each. The only thing that concerns me about this one is whether or not it would hold up to the HP you plan on giving it. other than that I think this would be a great diff.

The larger "auto-lock" that is pictured in one of the pdfs is for automotive use...it acts as a replacement for spider gears so it wouldn't work as a stand-alone diff.

The "front locking diff" seems to be an awesome idea. I talked with somone at Hilliard about this one and he confirmed everything awesome about it. The bummer about this one is that it requires a 12V power supply, but that 12 v power supply allows you to turn on and off the axles... meaning you could chose w/ the click of a button between 2wd and 4wd. These diffs also freewheel, so you will have to rely entirely on brakes to stop the cart and you couldn't engine brake. (you could engine brake w/ the sprocket-type auto-lok mentioned above). Expect to pay approx 250-300 bucks a unit for these bad boys.

hope that helps. it seems like you can get a killer set up for relatively cheap if you decide to go chain drive. If you are going shaft drive (like me) then I think it may be worth the extra $ for that front diff mentioned above.

I would be thrilled to get my hands on a locking differential for $60-100 that's not way too massive for my application.