- Nov 26, 2008
- Reaction score
- Camano Island, WA
Being as I dislike cold, anything below 50 F the fingers refuse to do as directed, what should be a day project is now hit and miss.
Changing over the AC motor to a treadmill variable speed DC motor, we hope. Not a great wiz at electrics other than its like water thru a pipe. I always start out reminding myself; Do not stick your finger into anything than has a cord attached. Do not power up anything electrical until it has been triple checked, if you dont know ASK someone.
So got this 2hp DC motor from a treadmill, controller and supply of tubing, If I can avoid the smoke test it just may work
Now there no reverse built in to this thing as received so of course the first try was just reverse the input, ah no, that doest work, never can be that easy. Time to map the motor and reverse switch wires out and I see that I have in the motor 2 big wires, 2 little wires and 1 green wire. As the green is attached to the motor frame it must be ground, gotta keep that one in play. The 2 big wires end up as such, into one side of the armature, out the other, into one end of the field and out the other. Hmm must be a series system whatever that is. The reverse switch is native to the lathe and its mapping is, well I dont know what its called. Flip it one way and some contacts make while others break and so on.
From forum searching the solution to getting the motor to reverse was found
Reverse the direction in which the coils are energized and the motor reverses.
So I dig into the motor and split the armature to field wire, splicing in extra wires (soldered and double shrink wrap) so I end up with 2 circuits as seen in view B
Ol Dukie giving his approval so I must be OK so far
. With this and the mapping of the FWD/REV switch its time to see if I can wire it up.
Got the plan mapped out
And the actual (the motions getting to this step are dull, cut and solder, wire ties are your friend)
Disconnected the motor power wires from the controller to allow testing with a small battery, Dont want to smoke the board. Hooked it up and ran the FWDREV switch thru its paces and YeeHaw, it rotates forward and reverse. Now its just mount it, dress it and use it.
Have to talk to that cat, seems even though the motor does the FWD/Rev bit it is stuck on slow speed. The controller does not alter the speed at all. So whats up with that? Back to the original motor wiring seems that the arm and field in series mean something, dont know what but shouldnt be hard to reconfigure the FWD/REV switch to alter the field polarity while leaving it in series with the armature rather than parallel as it now is.
Shorten the story of the last 2 months tinker it actually works as intended.
The 2 small wires mentioned earlier are for some sort of speed sensor attached to the motors armature, this in conjunction to a magnetic switch pulsed from a small magnet encased within the driven pulley (can see its wires in the shot) I guess regulate the controller read out. Mounted the original controller to the right side of the bench and with a push of a button (will grab a shot after I get the bench re-bolted to the floor) I can change speed at will. Ok so it reads in MPH, some Excel work as in =SUM((((4*(300/B9))*3.141)/12)*0.01136)*1.5 (1.5 is just a random pulley step up number, subject to change as experiments go on) may get me to the MPH to FPM realm for different materials and diameters, ya Im bored. Still have to get within the infield of the speed controller to pulley relationship, but for now 0.5 MPH and I can count the spindle revolutions, At 10 MPH, well its a lot faster than Im comfortable with, Good thing it will be bolted down to the floor.
Things to change, Motor brushes are mounted offset of centerline. Seems that its designed to favor one direction for brush life? To agree with the design need to remount motor 180 degrees. Can see why preferred method is mounting motor above lathe, chips dont fall up as well as they fall down. Have to fabricate some sort of guard for that. Figure out the speed pulley relationship for the controller and dump the multi-step to a single. Actually make something other than modifications.
And No Honey, I dont know what happen to your Tupperware