Planning/Imminent build of 4x4 kart

[SkidooTNT]

I understand the concept but I think you should YouTube rock crawlers and watch some of the crap those trucks do. They use the 3 link set up for a few reasons, it's easy to build and replace parts, it maximses the independence, and provides the most possible travel.

 

[lurch9]

As torque is applied the pinion of the rear axle wants to go down. This twisting will probably break the attachment point at the axle end.

A 3 link is actually a 4 link . 3 links that locate the axle front to back, 2 lowers and one upper, to control torque. The fourth link is the Panhard that locates side to side.

 

[SkidooTNT]

The way I've seen it the spring and shock, or strut assembly handle that on a 3 link system.

On his triangle system that isn't a factor. The triangle is solid to the axel and would absorb those forces. The only free pivot is the one between the triangle and frame.

 

[bread]

The way I've seen it the spring and shock, or strut assembly handle that on a 3 link system.

On his triangle system that isn't a factor. The triangle is solid to the axel and would absorb those forces. The only free pivot is the one between the triangle and frame.

I understand that the shocks's purpose is to keep the vehicle as level as possible, but their purpose extends to control the axle's location in certain suspension setups. What you have said is true, the triangle is solid to the axle, meaning that wherever the axle flexes to, the suspension arm complies to the limit of the joint, or the shock's limit.

However in my case, I don't think the shocks have anything to do with the positioning of the axle.

Perhaps when designing such a lightweight car, one can have trouble forgetting the stresses that a multiple ton vehicle puts on its sus. system. maybe this SAS setup will also help me get away with significantly larger tires (20ish in)

 

[Poboy kartman]

I understand that the shocks's purpose is to keep the vehicle as level as possible,)

No...this is been muddied by the advent of coilover shocks and struts. The purpose of shocks is to control spring rebound....Think of it this way: a spring is a bouncing ball..drop it ...and it will bounce...then bounce a little less.....and so on and so on...until it stops. Soooo...the "shock absorber " helps on the front end by taking a little more energy to compress the spring....(making the ball bounce less to start with...) but MAINLY to force that spring to work even harder against hydraulic pressure to eliminate that second bounce.

So...in no way...do shocks actually keep a vehicle "level" but limit the effect that the springs have in doing so...Small point, I realize....but.....

And without springs...gravity and natural forces...take it's place...but...again...doesn't keep it "level" just controls the rate at which the movement happens....

 

[bread]

No...this is been muddied by the advent of coilover shocks and struts. The purpose of shocks is to control spring rebound....Think of it this way: a spring is a bouncing ball..drop it ...and it will bounce...then bounce a little less.....and so on and so on...until it stops. Soooo...the "shock absorber " helps on the front end by taking a little more energy to compress the spring....(making the ball bounce less to start with...) but MAINLY to force that spring to work even harder against hydraulic pressure to eliminate that second bounce.

So...in no way...do shocks actually keep a vehicle "level" but limit the effect that the springs have in doing so...Small point, I realize....but.....

And without springs...gravity and natural forces...take it's place...but...again...doesn't keep it "level" just controls the rate at which the movement happens....

Thank you, I forgot to mention when I say "shocks" I mean coilovers, or shock and spring combo, etc

Point is, I'm pretty sure a 2 link is the way to go

 

[bread]

I find it hard to draw this so I'll try to explain...

I think what I want to do is start with the original output shafts on the worm gearboxes (3/4" OD) and put a 1" sleeve over it and weld it , then this sleeve will turn inside the axle housing (prob 1.25" OD) This 1" sleeve will be keyed at the hub end and will turn inside a bearing that is attached to the 1.25" axle housing. This axle housing is held in place by being welded to the sides of the gear case. This allows the gears to still be accessed when needed. For the rear axle, after the shaft is through the bearing, then comes the hub. For the front, after the first bearing comes the u joint, then the second bearing, then the hub (this means the front axle housing will be narrower to make sure the axles are the same width. The make the spindle and clevis, The clevis will be nothing more than channel steel welded to the axle housing at the correct caster angle, then the spindle will be a slightly narrower piece of channel inside the first one, kingpins being pointed outward to clear the u joints.

As for materials, I think the gear case is aluminum, so if the axle housing is steel, I'm not sure how that welds...

Suggestions?

 

[paddypower95]

I have a 110cc lifan pitbike engine which gives out amps to power a small 12v headlight (the power is from the stator so it varies deoending on how high the revs are). I was wondering if I could put a small 12v battery from a quad bike in the circuit, not only so I can add more lights without decreasing the brightness, but also so all lights are giving a constant light output
Thanks!
ps i'm new to this i dont know how to post sorry!

 

[ezcome-ezgo]

I don't want to sound like a Negative Nancy (no offense to all the Nancy's out there), but maybe you should consider this 1st generation machine without suspension. Seems like the drivetrain is complicated enough. Just my $0.02

---------- Post added at 12:50 PM ---------- Previous post was at 12:48 PM ----------

I have a 110cc lifan pitbike engine which gives out amps to power a small 12v headlight (the power is from the stator so it varies deoending on how high the revs are). I was wondering if I could put a small 12v battery from a quad bike in the circuit, not only so I can add more lights without decreasing the brightness, but also so all lights are giving a constant light output
Thanks!
ps i'm new to this i dont know how to post sorry!

Welcome. Please do not highjack others threads. Start your own discussion.

 

[bread]

I don't want to sound like a Negative Nancy (no offense to all the Nancy's out there), but maybe you should consider this 1st generation machine without suspension. Seems like the drivetrain is complicated enough. Just my $0.02

Yes that is always an option, which 1st generation machine are you referring to? If the kart lacked suspension, i am somewhat sure that it wont be able to negotiate the obstacles I need/want it to. I guess with my builds nothing can be normal. Any thoughts on the axle plan?

 

[ezcome-ezgo]

What I mean is this machine you are planning here on this thread is the first of its kind for you, right? Seems to me that if you work out and build the thing up so that it runs and works without suspension, maybe you could take what you've learned and build or rebuild with suspension. Tackle one problem at a time.

 

[SkidooTNT]

Not sure about him but some of us here live in areas where being suspension less would suck. The best places for me to go are quad trails and gravel pits. I don't have any streets or anything.

 

[thendrix]

As for materials, I think the gear case is aluminum, so if the axle housing is steel, I'm not sure how that welds...

Suggestions?

The short answer is it doesn't. If you want to combine aluminum and steel you have to bolt or pin the pieces together.

 

[bread]

Well, um the "4x4" thing just got interesting

Think i'll beat this thing up for a while, break something then convert to 4x4. The plan is still to create solid axles with either the worms or RAGBs and do a two link, just the whole project is now "where am I going to mount this?" rather than following a plan

is the torque converter flywheel (engine side wheel thing) suppose to wobble? (not spinning true)


....$375 produced this, complete with bent axle! sorry for crappy pics

 

[thendrix]

That looks like a decent beginning to a fun project

 

[bread]

Well more thought has gone into this kart with the arrival of the silver fox . Starting to drift from the one link/panhard bar idea because of unneeded complexity and weight, besides sourcing expandable u joints or cvs at this scale is difficult and the ones I can find are expensive. So the new idea is a swing-axle sus. What if I put the axle on a single hinge pin to swing on, this would facilitate tons of travel, and minimum cost, weight, and complexity. This hinge point would also be the Drive Shaft, meaning that the DS and the axle hinge rotate about the same axis. I do realize the massive camber changes the wheel experiences throughout travel, more than a link sus. The also major setback is that the sus. cannot "bump" all together, like if the kart went over a speed bump straight on, the sus. could do nothing because it would not activate the swing hinge pin (DS). You could straddle the speed bump and activate the sus. The last problem would be the twist when the DS is turning, its going to cause the axle to want to turn on that same axis, I think this can be solved with shock tuning.

If anyone is familiar with the euro trucks Tatra, they have a sort of similar setup where the axle half shafts rotate on the same axis as the DS.

Can anyone see why this would/wouldn't work?

\

Backbone

 

[bread]

forgot articulation shot, see the huge camber changes. I think the only thing preventing this amount of articulation is shock travel, not sure what kind of shocks can do this, Fox air?

 

[thendrix]

I assume you're using some kind of a coil over shock?

 

[chancer]

If it is NOT a rock crawler, you would probably never see that much Articulation, but still I don't know what type of shock will do that?

 

[bread]

Lets call it a crawler then, even so I realize that much travel will never be used, but yes probably coil overs will be the choice. the real question now is what kind of gearbox would work for this ?

It has to have four shafts because I think the axle would need two pivot points on the DS to be strog. I really can't find any gearbox of this type, anyone have ideas ?

My worm gearboxes won't work at this point because the input shaft doesn't come out the other end of the box