2:1 Internal & Spur Gear

[JRECPA at aol.com]

In a message dated 1/27/99 11:12:01 AM US Mountain Standard Time,
DanLlwln at ix.netcom.com writes:

<< This is not exactly EFI related - but my local sources have
 been unable to help me.
 
 I am trying to build an experimental transmission.  It uses
 an internal gear (teeth on the inside) and a spur gear (teeth
 on the outside) that rotates inside the first gear.  My only
 requirement is that the internal gear needs to have exactly
 twice the teeth of the spur gear (and mesh, of course).
 
 I went some automatic transmission shops, but all the sets
 of internal and planetary gears won't work because the planets
 are too small.  I was hoping internal and planets from different
 sets might work,  but haven't found a match.  I figured that
 buying some used automatic transmission gears would be
 the cheapest way to get some quality gears.
 
 Any ideas?
 
 TIA
 
 Dan L
 
  >>
Are you trying to use the spur gear as a planetary set up or just a
single gear to gear ratio?

If you are trying for a planetary set up it won't work because there would
be no room for a sun gear. That is why they use 2 planetary gear sets
to get the ratios under 3 to 1.

James