15 May 05
2 June 05
20 June 05

May 15, 2005

The gearbox comes with some M5 screws to attach it to the Mini-Ev and a suitable gear.  It has what appear to be machined metal gears and seems to be good small, but solid, 16:1 gearbox.

One end of the gearbox is an adapter that lets it fit the Mini-Ev.  The mounting holes on this prototype needed drilling out a little larger to be able to  fit the M5 screws provided as the holes did not align perfectly with those on the motor.  Correct alignment of the motor is still maintained as it actually is the large centre hole that locates around  the bearing housing on the motor..

I machined four small cutouts on the side of the adapter that will allow air to enter the openings on the front of the motor. This should greatly improve motor  cooling. Ted Z suggested this on the forum and I think it would make a good improvement to the design of the adapter. As you can see an old drill press and a milling cutter will do the job but not very  neatly!

The gearbox is held together using four M3 x 35mm screws and they only have 3mm or so thread where they attach to the Adapter. I'm going to look for some 40mm  long ones to increase the engaged threads.

The shaft on the motor must be shortened by 3mm and I did this using my trusty Dremel Clone. The nice yellow duct tape keeps filings out of the motor.

I pressed the gear onto the shaft using my bench vice. I was careful not to overdo it and bend the motor shaft.

I then did a trial assembly of the motor and gearbox. Everything fitted together nicely and ran smoothly when attached up to one of my 12v Hawkers. The combo makes  pretty nice package of a good big motor with a neat strong gearbox. it will be interesting to see how it performs in the finished bot.