10-06-2012, 12:30 PM
First thing, I want to thank Henry Arnold for his excellent how-to writeup on adding a motor to the z-axis of a RF45. I have modeled my install after his with some slight differences. My mill has the z-axis crank located on the left side which is awkward to use as I am right handed. I first added a gas spring which did make it easier to raise the head but still not what I wanted. Here it is before the mod.
[attachment=3152]
I am using the same pulleys and belt as Henry and sourced them at McMaster-Carr. I found a motor and controller on e-bay and mocked them up on the bench to see if the motor worked and could be reversed.
[attachment=3153]
With this working OK I had to next bore out the existing hole in the pulley to fit the crankshaft. This was the first time using the boring bar and it turned out OK.
[attachment=3159]
[attachment=3160]
[attachment=3161]
I designed the motor mount to use 2 of the 3 bolts that mount the crankshaft assembly. The 2 plates were cutout and slots milled for the motor mount bolts. This will allow the belt to be tensioned.
[attachment=3162]
The plates were setup and then welded.
[attachment=3154]
[attachment=3155]
[attachment=3156]
Here the motor is mocked up with the pulleys and belt.
[attachment=3157]
I built up a breadboard circuit to test the motor function.
[attachment=3158]
The first motor turned out to be too small and would not raise the head even after adding a second gas spring. Back to e-bay for a bigger motor. This one is 1/4 hp and lifts the head without a wimper. It may be overkill but it cost the same as the smaller motor and works. The next installment will outline the electrical enclosures and final installation.
[attachment=3152]
I am using the same pulleys and belt as Henry and sourced them at McMaster-Carr. I found a motor and controller on e-bay and mocked them up on the bench to see if the motor worked and could be reversed.
[attachment=3153]
With this working OK I had to next bore out the existing hole in the pulley to fit the crankshaft. This was the first time using the boring bar and it turned out OK.
[attachment=3159]
[attachment=3160]
[attachment=3161]
I designed the motor mount to use 2 of the 3 bolts that mount the crankshaft assembly. The 2 plates were cutout and slots milled for the motor mount bolts. This will allow the belt to be tensioned.
[attachment=3162]
The plates were setup and then welded.
[attachment=3154]
[attachment=3155]
[attachment=3156]
Here the motor is mocked up with the pulleys and belt.
[attachment=3157]
I built up a breadboard circuit to test the motor function.
[attachment=3158]
The first motor turned out to be too small and would not raise the head even after adding a second gas spring. Back to e-bay for a bigger motor. This one is 1/4 hp and lifts the head without a wimper. It may be overkill but it cost the same as the smaller motor and works. The next installment will outline the electrical enclosures and final installation.