reduction gear box

[Dman12]

Hello,
Is there any place to buy a reduction gearbox that can fit a 5/16" (8mm) diameter shaft? anywhere between 3:1 to 7:1 reduction will be fine.

I know there are motor that has a built in reduction box , but is it possible to buy them separately?

Thanks

 

[boostjuice]

http://www.evdeals.com/lashoutparts.htm

more pics...
http://mrbill.homeip.net/albums/lashout_planetary_gearbox/index2.html