PM45 - Moving the head height crank to the front.

[GaryK]

One thing I don't like about small mills is the adjustment for setting the height of the head is on the column on the back of the machine.
Very hard to reach and uncomfortable to crank. Also with my DRO on the opposite side of the machine it made it a stretching act to
read it while cranking.

I decided a long time ago that I was going to fix that. Here is the solution that I can up with. All it takes is some roller chain, two sprockets
and two miter gears for purchased parts.

The only limitation is the table can't be too far from the column or too far to the left. The crank will hit the table if it is. This is not that big a deal
since 90% of things are done with the table near the center of the spindle. If it is necessary to move the table out of the way it's well worth it.

I am working on a couple of improvements to remove this limitation though. I am also looking at using a wheel rather than the crank. I'm just not
sure about the leverage I will get on it.

Right no the crank is fixed with the same set screw that attaches it to the column. I was thing about add a couple of slots in it and a pin through
the shaft to allow you to re-clock it and turn it around like on a knee mill.

We shall see how these work out. If you would like prints and a parts list let me know and I will create them.

One good thing is that it doesn't require any modification at all to the mill and can be put back exactly like it was.

Gary

 

[Bama Steve]

This is an excellent upgrade and impressive workmanship.

I wonder if you milled some fittings for these things --> http://www.jegs.com/i/Titan/413/309...&cagpspn=pla&gclid=CJy9oNWEwbYCFQennQodvQoA7A and moved your crank to the left-outer-edge of the shaving pan, if that would completely correct your table movement limitation?



Looks good, Sir . . .

 

[8ntsane]

Nice work Gary, that should make life a bit easyer. :thumbzup:

 

[davidh]

looks nice, still waiting for my mill, im jealous. . . . and you could even go so far as to put power to it. . . like a cordless drill ?

 

[darkzero]

Pretty slick Gary, I like it. I thought for sure you were going to make something powered but that would be cheating even more.

 

[Ray C]

Good going there Gary... Oh how I hate moving that head larger distances! I'm still waiting for the right gear motor to come my way. That crazy crank takes a good bit of torque.

 

[GaryK]

Pretty slick Gary, I like it. I thought for sure you were going to make something powered but that would be cheating even more.

Good going there Gary... Oh how I hate moving that head larger distances! I'm still waiting for the right gear motor to come my way. That crazy crank takes a good bit of torque.

I may still add a motor, but I want precise control for positioning. Stopping a motor exactly where you need it is impossible. If I do add a motor it will just be to do gross movements.
Then since it will be geared it will have to be disengaged so that I could use the handle for precise positioning.

I'll also change the ration of the sprockets not only to make it easier on the motor, but give me real fine control with the handle. Like Ray, I'll be waiting for the right motor. I want somewhere between
60-120 RPM at the output shaft to move the head quickly.

Gary

 

[Bama Steve]

Check here --> http://www.surpluscenter.com/sort.asp?catname=electric&keyword=GIAD

 

[GaryK]

Check here --> http://www.surpluscenter.com/sort.asp?catname=electric&keyword=GIAD

That's one of the places I always check, but none of the motors have enough torque.

That's the place I bought the sprockets and chain for this project.

Gary

 

[GaryK]

Does anyone have a torque wrench that can check how much torque is needed to lift the head?

The lowest my wrench goes is 40 ft-lb/55Nm.

Gary