Custom Tracked Vehicle

[Tyler85uSMC]

To answer the few other questions yes it would be a tank please refrain from crushing my dreams haha. I believe it entirely possible to do and not real hard. Just time consuming. My budget isnt massive however i can easily stick money into it monthly and i do want to complete this idea as it is simply unrealistic for me to be able to buy what i want.
As far as undercarriage i dont see it being overly complicated but could add up in price, yes. I see building a frame around which you base the suspension and drive train. Suspension seems fairly simple to me, the drive train is where i definitely need the help and input. Internals wont have to replicate the actual vehicle specifically which allows me to build around what i have to make it work. The outside will resemble it and thats all in the armor, should be straight forward just bolting it on correctly and shaping right. The armor will not be solids metal they will be welded up to look right but weigh alot less. As i build it i see myself mocking it up with plywood or sheet metal to get the idea and then fab the pieces up as i go.
No it is not a dozer however i dont need it to reach top speed of the original or anything. I see no need for it ever to reach 30mph. Doesnt even need to be configured to run faster than 20 mph. Infact it would most likely very rarely reach 15 mph.
Any questions please fire away! It could be something i havent thought of and could help greatly or help someone else who searches for whatever information down the road.

[mjncad]

There are tons of YouTube videos on making small tanks that may give you the answers you seek.

[Tyler85uSMC]

You can use two standard diffs.
The first one is setup as a regular axle in a car/truck. The second one has the axle shafts connected to the first ones axle shafts, one side with gears, the other side with sprocket/chain.

You drive the pinion of the first axle to move forward/back. You then drive the pinion of the second axle to steer left/right. A hydrolic motor is a good choice for the steering drive. If the steering axle is driven and the drive axle isn't moving, you can turn in place.

Do you see this being complicated when driving and then wanting to turn while it still under load going forward/back or should it still turn fine?

[Tyler85uSMC]

There are tons of YouTube videos on making small tanks that may give you the answers you seek.

Yeah ive seen a couple kinda got me going, thinking bigger is more than possible. They had some interesting tranmission setups with what i saw, a few things from it i think can use but i am unsure of how much i can carry ever due to the sheer power differences. I think some of the simple principles like basic fabbing and the idea of them braking and is good to go and can be applied.
I cant believe no one has really posted much online anywhere about this. Either no one could get the resources and knowledge they needed to get it kicked off or its simply that hard, which i dont see being the case. Im a firm believer that where there is a will there is a way> I dont think its to awful pricey to get the dfrivetrain setup just a little beyond my knowledge on putting it all together from scratch. Ive already got some help on here which is awesome I wasnt sure how that woulld go.

[MBTRAC]

I've always wanted to build some sort of small tracked recreational vehicle myself - something along the lines of an amphibious tracked Argo, as I have earthmoving gear for excavating...etc... I don't need it to be anything other than a fun project.

However, I haven't progressed beyond the initial concept/design staged & accruing some assorted parts primarly because of time - my initial inspiration was this photo which I saw on the internet (it may have been this site )

Anyways for what's it's worth, conceptual IMO the cheapest/easiest way around the expense/complexity of track gear should "in my theory" be driving through a vehicle diff/axle fitted with:-
1) an "on demand" air locker diff to provide even power to each track for straight forward/reverse momentum
& 2) seperate brake actuation to each brake disc to enable steering through individual track braking (with the air locker disengaged)

The commercial track sprockets/idlers/chains/grousers & rubber tracks I have deemed too expensive for my project, & self built rubber tracks (like this photo) too time consuming & too much trial/error - so I've purchased at a good price at auction a set of Bobcat Skid Steer over wheel tracks which allows me to use standard car wheels/tyres for the drive sprocket's/idlers & homebuild the track frames (again like this photo)

Good luck with your build & please keep us appraised of progress.

[CNC Dan]

Do you see this being complicated when driving and then wanting to turn while it still under load going forward/back or should it still turn fine?

Works fine steering while moving.

[PapaPerk]

Hello guys,
I need some help being pointed in the right direction. Im looking at building a large tracked vehicle. I am looking to get the drivetrain put together first. Where im getting a little confused at is with the actual way of putting power to the tracks. Here is what im thinking, one of 2 ways i see doing it, is either or possible or is one better than the other, I like the idea of the first one but is it possible if so thats the one id focus on? I am sure of how other real vehicles do it and havent had much luck searching for it other than this is where ive gotten to with my searching so for. If neither are good what is the basic setup i should be looking at? Ideally i would like to get this kicked off this winter and document for others to see on the forum.
First route i want to run it off of a diesel truck engine. Now can i run it through a standard transmission then to a differential(like a normal truck) then have planetary diffs on each side that would connect to the sprockets to power tracks. Would each planet diff need a hydraulic pump? Then do i plumb each of these into a steering valve and thats how i turn? For breaking i believe i would utilize the brakes on the truck diff to have a type of parking brake for each side, i would have a one pedal control for both to apply brakes and i would have a individual lever for each side for emergency turning/ brakeing.
Second route is to have a hydrostatic motor ran off of my engine running hydraulic motors on each side. Can i then simply route my steering through these motors controlling my speed and my steering? I am a little confused on this second route and the first seems simpler to me. Can this setup move a large vehicle upto a decent speed or is it a pretty restricted design. Is there another route of doing this that would be better? How does the drive train on older bulldozers like pre Cat D6 work? Isnt something like the first route
Any help is appreciated!

Tyler

Here ya go. Notes on Tracked Vehilcle Steering

If you wanna put all the power to the ground and have high top speeds... avoid hydraulic.

The most basic system would be an axle with disc brakes. Grab the rh brake to turn right... lh to turn left. Of course it's hard on the diff... but it all depends on size of vehicle you are talking about.

[Tyler85uSMC]

ok a couple questions in regards to hydraulic motors now. If you have a hydraulic motor connected to the input of a differential(like where the driveshaft connects) can it sit there connect and the differential spinning and it not effect the hydraulic motor, basically the motor in a nuetral? And then be activated to go left or right and engage the driveline, causing it to then turn forward or reverse?
Would it be better to have the diff input hooked up through a worm wheel and the hydraulic motor hooked up to a worm gear? Thus the worm wheel spins which ever direction from the diff but then the hydraulic motor engages and turns the worm gear a direction causing the worm wheel to be engaged? A worm gear and worm wheel operate in that manner correct? That is at least my understanding of them a load can be placed on a worm wheel and it will not engage the gear. Only the gear can engage the wheel?
Last question, is it possible to run a hydraulic pump off of a front output on a transfer case? For example you have the driveline ran through the transfer case like normal to the rear. The front would have a pump connected to it. I ask because you could run a pump off of a pto but then you can drive at the same time but if you could run it off the transfer case output it would always be powered and you could drive. Would it be easier to just run a pump off of the motor? Or are you really limited in if you run it off the motor?

[bcp]

Worm gears normally stay engaged. The worm can turn the wheel, but the wheel can't turn the worm, except for low ratio gears.

Worm drive - Wikipedia, the free encyclopedia

[David Devuono]

If I were to do it all over again I would go with (look up) 2/5 scale tank transmission. I went the Hydraulic route, spent thousands, and almost 2 years later I am still working on it, though with less enthuesism. Hooking a hydraulic motor up to a differential, you have to take into account the gear ratio. IE if you bought those 160 RPM wheel motors and put it onto a 4:10 differential, you would have 40 RPM wheel speed.(slow) If you have the transfer case, then you have the transmission too, so no need to add hydraulics.

My vote is for the 2/5 scale tank transmission with double pullys for at least forward shaft.