Dozer questions

[buzzy16]

So with my tonka dozer conversion I am going to have some questions before I really get in to the build, even though this is going to be a slow build.

I thought one thread for all my questions was better than a different thread everytime I am unsure of something.

So firstly does it matter where the drive sprocket is located, for instance most builds have the motors driving the back sprockets, but can I have one track powered from the back sprocket and the other track from the front one or will that cause problems?

Also I saw on a thread the other day someone mentioned using grease to tension the chain insted of a chain tensioner, how does this work?

For those that have built dozers have you used bearings or just bushing or nothing at all where the drive shafts go through and the idler wheels?

Thanks you in advance any help is greatly apreciated

Buzzy

[Lmackattack]

You should try to power both tracks from the same end. You may find it will "walk" side to side when trying to go forward or backwards...


If by chain your talking the tracks....real dozers use a idle wheel at the front. Grease is pumped into a chamber that pushes the idler wheel forward and thus makes the tracks tighter helping prevent them from jumping a tooth or completely falling off the sprocket.

[buzzy16]

Originally Posted by Lmackattack

You should try to power both tracks from the same end. You may find it will "walk" side to side when trying to go forward or backwards...


If by chain your talking the tracks....real dozers use a idle wheel at the front. Grease is pumped into a chamber that pushes the idler wheel forward and thus makes the tracks tighter helping prevent them from jumping a tooth or completely falling off the sprocket.

Thank you for replying, I thought I'd better ask that before I made any plans on where to place the motors.

So where a lot of the guys use springs to tension the idler wheel you can use grease instead.

[Lil Giants]

I have never seen any small scale dozers using grease for tension... coiled springs would be much cleaner & easier to incorporate.

[sparkycuda]

While I realize using springs for track tension is the easy way to do a model, the grease adjustment on a 1:1 does not keep tension on the track, it only sets the clearance or "slop". Our model spring tensioners do zap some drive power by keeping the track tight all the time. I believe Joe's (dirtpusher9) Cat dozer uses a simple set screw lock to hold the track adjustment without a spring, and simulates the grease adjuster on the real machine.

Our model motors seem to have enough power to offset the extra needed to turn a chain while under tension, so I guess it's whatever you want to do.

Ken