Converting to less/better chains

[Rabbit929]

So I am a curious beast, what if, we converted the four corners to run off the same chain? Or tie all three axles together, and one big chain to drive em from the center? I want to reengineer my 6x6 to be loweraintainance, because I barely use it and my main chains off the t20 already need adjusting.

Brainstorm with me guys.

[Rabbit929]

I should also say that shaft drive a been discussed, which would be awesome if there was a lightweight way to do so. (Without gearboxes on every axle)

[john swenson]

rabbit.. i did alot of research regarding the shaft drive awhile back. with the subframe design on my max 2 it would have been fairly easy, but the gearboxes i found that were affordable could not be used in water and the specs on them did'nt guarantee they would hold up. there were some built for both those uses but were very exspensive . i'm not sure of a way to do the shaft drive without a gearbox at each axle. i have alot of room on my subframe max cause the sprockets and chains are all outside the tub. it's worked great for me. easy on my back and east to adjust chains,change bearings etc. i could run 1 chain to drive the front and rear axles and the center would freewheel which would be fine for tracks. but if you looped one continuous chain that included the center axle, that one would turn in reverse. keeping thinking !!! johnboy va.

[dirtdobber]

Something I have thought about, but haven't really researched, is an exposed bevel gear setup. there are plenty of agricultural applications that run bevel gears exposed to the elements. Chain drive to the center axle and from there convert to shaft with exposed bevel gears. Pardon my artwork, but something like this:
bevel drive.pdf

[john swenson]

dirtdobber.. i thought the same way and i think your right.. exposed to the elements, the gears should be o.k in most cases. easy to keep clean and lubed. less cost than gear boxes, and take up less space. a guy could probable fab a simple '' boot '' to cover the gears also. you drawing is good. the ticket would be supporting the shafts in bearing blocks so gears stay meshed well. j.b. va.

[Noel Woods]

I should also say that shaft drive a been discussed, which would be awesome if there was a lightweight way to do so. (Without gearboxes on every axle)

An open differential driving a set of wheels (either front or rears) should work ok with tracks. Just rig up a set of brakes on the drive axle to assist with steering. In terms of a single chain going front to back my opinion is there would be too much deflection in the chain and constant adjustment. Some of the Attex racers just used one chain to connect the middle and rear axles and this was termed the "high torque" set up. I am with you in always trying to build a better mouse trap. I like John Swenson's set up, nice and simple and rugged.

[john swenson]

yes noel....i traded the hassle of working on all the chains, bearings, adjusters, sprockets and axles for having them exposed outside the tub. but in the 3 years i have run it that way ( busco has been a great test), i have not seen any more wear and tear on those parts than inside the tub. of course i went with the 4'' bearing cages and # 60 chain and sprockets. all has held up well plus higher ground clearance and plenty of tub clearance for tracks. and i worked out all the bugs in the design after some ''test'' time. i've been throwing around the idea of going to 1 1/2'' axles and ''27'' tires. sort of a '' bigfoot '' max 2. ....... who knows ..... johnboy va.

[Rabbit929]

I love the beveled gear idea. And he’ll, while running tracks maybe you’d only need power to two wheels on each side? It’s be lightweight and rugged if done right.

@ John, Where do I find photos of your exterior chain set up?

[Noel Woods]

All tanks that I know have that have ever been produced utilized a single drive sprocket to turn the tracks. I have tried the concept myself on a Max2 with tracks when I lost a chain adjuster and went down to one wheel drive on the right side. It worked pretty well with tracks on, and I rode with friends for several hours before the ride was over. In mud the machine performed very well, it still swam decently as well although the left side performed better than the right side while swimming in deep water.

The beauty of this kind of set up on a project machine is that someone could create a ratcheting style wheel/bogie adjuster to maintain proper tension all the time.

[Rabbit929]

All tanks that I know have that have ever been produced utilized a single drive sprocket to turn the tracks. I have tried the concept myself on a Max2 with tracks when I lost a chain adjuster and went down to one wheel drive on the right side. It worked pretty well with tracks on, and I rode with friends for several hours before the ride was over. In mud the machine performed very well, it still swam decently as well although the left side performed better than the right side while swimming in deep water.

The beauty of this kind of set up on a project machine is that someone could create a ratcheting style wheel/bogie adjuster to maintain proper tension all the time.

That’s my thing. I know there’s a way to make the drive trains on these things better, stronger, and lower maintainance. I think that’s always been the holdup on their popularity. Everyone around here enjoys mine, but a side by side or four wheeler with a canoe will do more with half the money.
Long story short, chains are high maintainance and out dated. A lot of moving parts and friction, which is why all nice motorcycles are either belt or shaft drive. The only bikes with chains are ones looking for less power loss.

So chain drive = 6% power loss
Belt drive = 11% power loss
And shaft drive = 20% power loss.

It’s not like anything can’t be counter-acted with a bigger motor.