Catterpiller Track drive unit

[doug72]

When building tracked vehicles I prefer to use a subtractor unit for drive and steering using the 16 / 24 toothed differentials.
With motors attached these can take a lot of space in a MOC. Additionally two right drives are required to the track drive sprockets.

Found a better solution in Sariels excellent guide book for a Studless Transverse Subtractor unit shown on pages  291/2.
These worked but found awkward to incorporate in my MOCs due to its cube shape.

I set out to build a “flat” version using 28Z differentials and after a lot of trial and error achieved success.
Unit measures 13L wide x 7L long x 4L deep without motors. has the added advantage that the right angle drives are no longer required to the drive sprockets.

For my planned MOC the drive input will have an 8:1 reduction and steering input a 24:1 reduction to get the very slow track speed I require.

I have built a demonstration unit ( multi coloured) to show how this was built.

See photos:-

L motor for track drive and M motor for steeing.

IMG_4123 by Doug Ridgway, on Flickr

IMG_4124 by Doug Ridgway, on Flickr

IMG_4125 by Doug Ridgway, on Flickr

IMG_4126 by Doug Ridgway, on Flickr

 

PS Can the moderator correct the spelling in the tile box for Caterpiller - thanks.

Edited October 15, 2016 by Doug72
added text.

[Sariel]

Um, but my book has a "flat" version too, not just the cubic one. And it's very similar to yours:

[doug72]

Sariel, yes I am aware of it but wanted to build one in studlless and using the 28Z differential to eleminate the right angle drives.

Not keen on studded construction prefer studless.

Doug

[Sariel]

Oh, I see.