Mini Mill Tune Up And Power Feed

[bmac2]

Have to love the 3D printer for making up quick and dirty jigs and fixtures. I guess that's the Rapid Prototype part of RepRap. Print it, use it, and into the recycle bin. The Oldham is working like it should and the clutch engages and disengages freely.



After test fitting it in the existing frame I think with a little work I’m going to keep going and see if I can just use it. First thing I’ll have to do is cut down the plate that mounts to the table. After putting it on I realized it would hit the DRO on the Y axis.

 

[bmac2]

For speed control I’ve tried running the motor with PWM and it just doesn’t like it, not all DC motors will work well with PWM. As I said before the motor has plenty of torque down to 5v so I’m just going to use a DC to DC converter similar to this one.

For direction control I could use a simple DPDT (double pole, double through) momentary contact switch but surprisingly I don’t have one. What I do have is a couple of self centering joysticks. With the joystick I can eliminate the need for end stops. If something starts to go south I can just let go and it stops.
I just had to make the control circuit. I was thinking of using a MOSFET H-bridge but if I’m going with the frame I have I would run into space constraints so in the end I decided to just go with relays.

Made up the circuit on a breadboard and it worked so I pulled out one of my favourite toys, my little engraver.

And don’t forget to clean the flux off the board. There’s a special place in hell for those that don’t clean their boards.

If anyone is interested this is the schematic

View attachment J_Stick_Board.jpg