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View Full Version : shaft mod with belt xfer vs. gear xfer?


cdog4w
03-08-2004, 03:53 PM
I've been looking at doing a shaft mod to maintain 4WD with a normal motor. I've almost got all the parts I'll need, but I've been thinking about the aspects of it that bother me. It seems most mods like like this have used a gear transfer, and it is usually pretty tricky to line up the gears properly. Even if you get the gears to line up, theres no guarantee that the next motor you try will. In the meantime I was trolling the xmod forums again and saw this post.

http://tinyrc.com/forums/showthread.php?s=&threadid=18471

I was wondering what you mini-x people thought of doing a belt transfer instead of a gear transfer?

So aside from not worrying about gear mesh, you could also play with the pulley size ratios much easier than with gears.

The disadvantages would be potential breakage and belt slippage. Can you think of any others?

EDIT: Any idea where to get the pulley parts? The referenced thread used a VCR repair shop... are there any rc airplane parts that might work?

potentiality
03-09-2004, 03:44 AM
Pulleys have more rolling resistance than gears. An xmod would get some benefit because of the slip. However, you have a better system with a car that has ball diffs that are made to slip.

Realize also most belt systems in larger r/cs use pulleys with teeth so as not to slip.

Pulleys are used sometimes to make a more accesable drive train. That is there only real benefit.

I would think two larger plastic pinions (15-16 tooth) would be your best bet. Plastic ones from like an rs4 or a m18. (they should fit on a 130 and 180 shaft.

Cian
03-12-2004, 08:38 AM
Saw this on Mini-z-bar....

http://www.mini-z-bar.com/page043.html

cdog4w
03-12-2004, 12:54 PM
Thanks for the link. That guy's conversion car has been linked before and is just awesome.