Custom Tracked Vehicle

[Tyler85uSMC]

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

[hr3]

http://www.tractorbynet.com/forums/b...smissions.html Check this out for starts... I'm looking at making something small scale but for heavy loads....

[Tyler85uSMC]

Ok so that solves and yet complicates things haha. If you were to go the double differntial route, you would have a hydrostatic pump running off your motor. That in turns runs your hydrostatic motor. Now would you have the pump powering 2 motors or would the motor have to outputs? Either way this then turns your shafts running your 2 differentials correct? So is it possible to connect two vehicle diffs for this type of setup with some kind of reducer gear or something at their ends or is the only real option to buy one that has been built from a company?

[CNC Dan]

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.

[Rustyiron]

What will the purpose or use of this vehicle be?

[MarkV]

I think some more information would help. When you say you want to build a "large" tracked vehicle I start thinking it can cost well over 10k to replace an undercarriage on a small tracked vehicle. Depending on what you want to end up with it might be better to start with something already tracked. Of course you may have a bigger budget than my projects do.

MarkV

[Leejohn]

Hyd. wheel motors?

[swick1]

We need to know your purpose as the speeds attained will dictate the entire design. A tank is very different from a bulldozer

[bcp]

Catamaran snowmobiles

Bruce

[Tyler85uSMC]

Hyd. wheel motors?

I am unsure if you are asking based on if i said something or if you are asking if i have considered them. Ill take it you mean by what i said in the second route option. I may have used a incorrect name to describe what i was describing. I dont know what kind of power they would be capable of but this is what i meant, well something bigger than this but you get the idea
Google Image Result for http://www.surpluscenter.com/images/p9-8092C.jpg
Id rather not go this way but would if it was the only option.