Monday, March 22, 2010

Creating a 12V drive motor from a cheep HF winch

I started this project looking for information on how to use a cheep HF winch as a drive motor for a trailer dolly, but this could be useful for driving other devices. using a winch motor is appealing because;
They develop high torque
They are inexpensive
They have a built-in gearing and a clutch to allow freewheeling.
This project attaches the sprocket to the spool allowing the use of the winch gearbox and clutch. if you want to bypass the clutch and gear box their is a wonderful discription here:

http://www.diyelectriccar.com/forums/showthread.php/more-e-bikes-19924.html



<<< Spool and clutch disassembled. I started with a cheap HF 2000 lb winch motor, purchased on sale for $39.00. to this I wanted to attach a 18T #41 sprocket. I started by removing the cable from the spool and the spool from the winch. You’ll also have to remove the clutch mechanism from the spool.






Sprocket and spool layout:
Left I laid out the sprocket and the spool, this is the motor end of the spool. I was only able to get the sprocket with a 3/4" bore and the center spindle on the spool is 1 1/4" dia., so beside having to cut off the out-board spool end I also had to bore the sprocket. both of these operations require a lathe, if you don't have one you'll need to find a machinist to cut these down for you. it took about 1 hour for me to do both parts.











Machining the sprocket and spool, I've included some pictures of the machining. I think they are self explanatory. I turned the spool and the sprocket bore to 1.25".






























Then I drilled, tapped and counter sunk 6 holes for 10-32 flat head socket bolts, and screwed the sprocket to the remaining spool end, the motor end, using red lock tight high strength.




Finished drive motor with sprocket attached and assembled. notice the freewheeling clutch "T" handle to the right of the winch assemble.