Motor Case for Mabuchi 775, Ryobi saw motor

thingiverse

If you are looking for a very high torque small electric motor, this is a very inexpensive setup. Turns out the Ryobi R10633, 18V, 5 1/2" trim saw has a Mabuchi RS-775WC-8514, you can pick the Ryobi saws up used on ebay for 20-25 dollars. These motors sell for 50-70 bucks new without the gear box. Use the gear box and motor case that comes with the saw with this 3D printed case. The Ryobi gear case has a very strong 9-42 tooth gears in it. The Ryobi output shaft is 10mm and will take a 3/4" OD flexible shaft coupler or 10mm ServoCity set screw hub. There is a nice big 10x26x5 6000Z ball bearing in the gear case output shaft you can use in the 3D printed case. The Mabuchi RS-775 motor puts out 1561 g-cm of torque at 17040RPM at 18Volts. That is 5 times the torque of a RS540 motors 312 g-cm. The RS-775 motor will work on voltage from 6-20 volts. The Ryobi gear reduction cuts the RPM down to 3651 and ups the torque to 7285 g-cm. Gear it down from there and you have a motor that will run about anything. Here are the specs on the Mabuchi motor http://www.mabuchi-motor.co.jp/cgi-bin/catalog/e_catalog.cgi?CAT_ID=rs_775vcwc In one of the pictures you can see the difference in the motors. That is a 370 motor on the right, a RS-540 Mabuchi and 550 Titan motor in the center and the RS775 on the left. The RS775 is huge! Use 8x3/4" sheet metal screws to attach Ryobi case to the 3D printed case. There are two gear cases one to mount up from the bottom and one to mount up from the output shaft side. The bottom mount has a 2 1/2" x 5/8" bolt pattern on bottom. Was going to use these gear boxes to run a large scale 1/6th Cat RC bulldozer I am making, but the Ryobi gears where to large to fit in the dozer. Used the motors but had to design my own gear box for the RS775. These motors are brutes, very powerful running them at 12V, 18V would be very interesting. One drawback is this motor takes 18.7 amps to run it, you will need a pretty heavy duty 20-30 amp motor speed controller to control the motors speed in a robot or RC vehicle. Please use caution around children. As with any gear drive or belt drive, (If you ever want to play the guitar) never ever, ever get your fingers close to the pinch point of gears (especially this one), belts or spinning saw blades. Make sure you hold on tight or mount the RS775 motor before starting it, this motor makes some serious torque. Have fun and be safe!