Paul,
Are you being deliberately difficult ;-) ???
I hunted around for a half hour trying to find
this link. It would have been a lot easier if you just put it there for us.
Anyway, the bottom line is the Mabuchi motor is a weak little guy.
At 12 V:
5.2 Amp stall
4700 RPM Free Speed
.06 N-m stall (620 g-cm)
Bottom line, PEAK POWER (watts) = 4700 * .06 / 38 = 7Watts!
Not a whole lot to work with.
If I were going to use this motor, I think I would by
this motor/gearbox from Lynxmotion.com for about $20.
The reason I would do this is that you can easily (10 minutes with a lathe or drill press plus an arbor to press off and on gears -- easily done) make this motor fit in this transmission (see pictures below).
The beautiful thing is you get a 100:1 ratio. That gets you to 3-4 N-m (accounting for gearbox inefficiencies) stall and 47 RPM free speed.
That to me seems more useful, all for $20 and a few minutes of labor.
Free advice from THE Dr. Joe -- accept no substitutes.
Joe J.
P.S. All you have to do to make this motor fit is to open up the hole in the middle of the aluminum part in the middle of the second picture to be 13mm Dia. I think it is 8mm now. The rest is a direct bolt in after you press off the gear that is on the Mabuchi and then press on the gear that the transmission was designed for. Assuming my sources are true to their word that is. If anyone does this, I would like a report on the progress.
P.P.S. The output shaft of the gearbox is a 6mm round shaft - perfect for a 6mm trantorque from McMaster.com