I had a crazy idea a while back.
While ordering the button cells for the Layman's mod, I picked up a couple of
Small DC Motors from Allelectronics. These are much larger than the bit motor, but smaller than your average hobby dc motor. From the dimensions listed on the web page, I thought I could possibly fit one in a bit. Thus was born the BFM-9000 project (incidentally, named after Doom's Big Friggin' Gun).
I had in mind a high-torque monster bit from the beginning. The motor is rated at 15800 RPM at 2.4v 96ma, so I knew that even with dual cell it wouldn't be super-fast. I decided to push it a little and give it 3.6v though, and I chose a variation of the Layman's button cell mod using 3 80mah button cells. This would overcome the current-providing limitations of the smaller cells and allow better run times, but naturally would not fit in the same space without modification. Shown in the first three pics is a size comparison between a bit motor on the right, a clone motor on the left (the "large" type that will barely fit in a bit motor mount), and the BFM-9000 in the middle. Also, you can see a strip of the three button cell batteries I used, shown next to a stock bit batt.
edit: oops, the batteries are 80mAh, not 70.
The BFM-9000 Motor Mod (tm) (pics)
Threaded Mode
