PM-30MV for mcdanlj

The nylon locking ring in the nut didn't quite engage the threads, so I bored out another 0.1" and now the nut now tightens securely:

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While I was at it, I added some bevels. The innermost bevel makes threading the nut more comfortable. The large outer bevel just makes it a slightly better visual match for the other hand cranks and looks a little better. I didn't measure any of the bevels, just eyeballed them.

Here's what the profile on the back looks like:

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The upper part is just a copy of the shaft in the back of the existing crank, and the index wheel fits over it with the spring in the groove. The bottom part is slightly longer than it really needs to be and has my attempt at a J4-like profile cut into it. (Probably it will shred the belt and I'll start over after grinding a new attempt at a form tool.) The dimensions aren't critical.
 
I am so happy to find a PM30MV owner posting about their experience with this mill. I am one click away from ordering one and will also be sharing my experience.

Your power z-axis build looks great. I wonder is you are planning to do a CNC conversion on this mill in the future. I have a Grizzly G0762 mill that I am going to leave for manual machining and hope to do a conversion on the PM30MV.

Thanks for sharing!

Mark
 
@Landmark I'm about to start my project to CNC my first mill, a HF mini-mill. I could see someday if my appetite for this hobby keeps increasing that I would someday buy a larger mill and CNC the PM-30MV, but for now no such plans. :)
 
My power lift project went on the back burner for a few months. I was a fairly active Google+ user, and when Google announced that they were shutting down Google+ in April instead of August I went into overdrive saving information from Google+. About 50,000 posts, with about a third of a million comments, saved from Google's short attention span. That set me back a few months.

I used almost entirely scrap to build the lift. Bearings that I removed from a treadmill motor that had squeaked under treadmill load but were fine for this purpose. A few chunks of aluminum from the local scrapyard. The non-scrap pieces were a belt, most of the screws, and a few inches of aluminum rod. Everything else, including the new crank wheel I posted about last year, were 100% scrap. This makes me happy. The motor is from a dead hedge trimmer, and uses the gearset from the hedge trimmer. I haven't measured diameters, but I also am getting something like 2:1 advantage from the J-belt pulleys I cut. I hate free-hand drilling cast iron to mount it on the column, but at least tapping M5 was trivial.

I haven't done the trivial electronics, nor designed and 3D printed a case for the motor to keep chips out, but when I hooked it up temporarily, the head moved at the maximum speed I would want, and I can still crank the head by hand to move it short distances more precisely. Exactly what I wanted.

Rear view:
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Rear quarter view:
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Front quarter view:
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Top view:
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I hooked up a momentary-on / off / momentary-on DPDT switch between the bridge rectifier and the motor, with the input connected to the inner terminals, and the outer terminal cross-connected and connected to the motor. It defaults to not connected, but while I'm actively holding the switch up or down, the head moves up or down respectively. There are no limit switches except for the one in my brain, but if it hits physical stops I expect the belt to slip.

I had thought of mounting it in the hole where the "safety" shield (you know, the one that makes the mill unusable, and as long as you aren't using the mill it's safe...) wires were routed, but there's not enough room there.

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So instead I mounted it on the DRO arm. What I have now is a minimally-sufficient prototype to decide whether I like the current location or want to move it. So far I like having it near the Z locks and quill arms.

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This runs just about as fast as I would want, and it works great. I can still do fine adjustments cranking by hand, but mostly I won't need to.

Keep clear of the spinning hand crank!

 
Orange cleaner (limonene) is great for removing adhesive without damaging plastic- your hunch was correct
I use something called "Citra-solv"
M
 
This runs just about as fast as I would want

...Or even slightly faster. Because I couldn't find a 3+P3T (m-on)on(m-on) switch for less than $50, I'm not shorting the motor leads when I'm not actively driving it, so the head coasts when I stop lowering it under power, which means that I have to be careful about possibly crashing the tool into the work. So it's a good thing I can still use the hand crank for the last fraction of an inch when it matters. Usually I just take up the last cm or so with quill travel.
 
A light duty switch controlling a pair of relays would let you short the motor when off, I'm sure you thought of that already
 
@markba633csi I hadn't, mainly because I'd been thinking of an h-bridge and a potentiometer input for PWM speed control.

Probably I won't get around to it until I crash an expensive tool into a part that I've just spent three hours on, trashing the part and the tool, and then I'll re-read this and roll my eyes at myself. :rolleyes:
 
In another thread, I wrote:

I got PM's 5-inch vise with the PM-30 and have been satisfied.

Today, finally, I made locating keys for the vice, because I have upcoming projects that are going to require several setup changes. It's a pain since the device has 16mm index keyways and the table has 14mm slots. I cut keys that are 14mm for the main body, but have about a 3mm 16mm lip to index them to the vice keyways. It fit in smoothly with no disernable play, and then checked running the table back and forth in X to test with an indicator how true the vice was.

This is how I discovered that the index slots in the base of the vice are about 1/3mm out of square, which results in over 1mm out of square over full X travel. I'm slowly filing and testing one side of one key until the vice rotates into position to be square, after which maybe I'll be annoyed enough to cut special out-of-square keys that again fit with no play.
 
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