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

 

[bmac2]

Made up a board to hold the joystick and soldered on some 3mm threaded inserts for mounting it. Next up was to make a bezel for it. The engraver can do soft metals but with very shallow cuts and very slow feeds and a new/very sharp mill. It took just over an hour to cut it out.

So now I needed a boot. The joystick is cool but it’s wide open. I’ve spent a few hours scouring the internet and the local hobby store websites for anything suitable but have come up blank.

As long as my wife really wasn’t using this pair of gloves I’m golden. There rubber kitchen gloves and where way in the back under the sink and look a little grubby so I’m pretty safe.
I cut off the thumb and poked it through the hole in the bezel then stretched it back over the outside. Put it on a warming plate thinking that it would soften and keep the new form.

After about an hour low and behold it worked! I wasn’t a fan of the blue colour and while it was cooking I tried a few things on the remains of the glove and found that permanent felt marker didn’t rub off and I couldn’t wash it off with isopropyl or WD40 so now I have a nice black boot. I have to wonder if putting it in boiling water would have worked.