Power feed on PM25MV installation, wrong bracket

[WobblyHand]

I bought the power feed when I purchased the mill, but just got around to starting the installation. Something about not having enough electrical outlets. Recently fixed the outlet issue by running a couple of 20A circuits. When I got the power feed, I briefly looked at the instructions that came with it, and couldn't understand it at all. The instructions seemed to have nothing to do with a PM25.

Yesterday, I went to the PM site and found a new (to me) document to download. It was a lot more understandable, and it became obvious what to do. I thought this would be a project of the day. Not quite. However, I managed to install this.

Surprisingly, the gear adjustment was pretty easy. Once I figured out the rheostat setting was too low, could get the table to traverse back and forth. Not too much gear noise.

Unfortunately, the mounting bracket for the limit switches is incorrect. The bracket is rectangular, with 2 of the holes in the wrong place. The supplied bracket would block the oiler on the Y-axis. It isn't tall enough to pickup the two screws. It is just the wrong piece.

The two outer holes on the bracket are correct for the limit switch. The two inner holes do not match my machine. The bracket is not tall enough to have both vertical holes.

Of course I could make one. As you can clearly see, I do have a mill. It is disappointing that the wrong part was supplied. (But it is my bad, that I hadn't installed this in a year. Should have noticed this much earlier.) Does anyone have a sketch of what the bracket should look like? I'm guessing something like an inverted tee, but it would be nice to have the right spacing for the holes. If you have a sketch of the part, or a photo, it would be great. The photo in the PM download gives a hint, (what I received is incorrect) but not quite enough to design to.

Cable management seems to be left up to the user. Not sure what I am going to do just yet. The power feed isn't that professional looking in my opinion, but it does work. Bending cables as shown above, isn't a good thing to do. The limit switch cable will be subject to a bit of wear

 

[WyoGreen]

The bracket was wrong on my PM30, and seems to be wrong on other peoples machines also (Check out Blondihacks youtube for her fix on it). I made a bracket for mine, but recently had a project where I needed a fixed stop, which the switch interferes with, so right now it is hanging off the end of my machine. Frankly, I've never come close to hitting that switch, so I'm not sure if I'll put it back. (I never walk away from a running machine.) I'll try to get some pictures of my bracket tomorrow.

 

[tweinke]

The bracket was wrong for my PM 727 also. was able to modify it though (no oiler in the way)

 

[WobblyHand]

shows a guy drilling out his PM25. Not what I want to do. Don't like hand drilling into things, if I don't have to.

Probably going to make my bracket out of aluminum. No real need for it to be steel.

Disappointed this is considered normal by PM to have to re-engineer bits for their "power feed kits". Especially since they are claimed to be custom for a model. It wouldn't bug me if they said you need to design a bracket, here are the guidelines. The implication is they would just fit. Not true.

 

[WobblyHand]

Made a design. Printed it 1:1 and cut it out to confirm fit on the mill. (A version of cardboard engineering!) Decided I wanted it to be a little wider in places and made rev 2. Cut a 1:1 print of it and fitted it to the mill. Looks ok. Found a chunk of 7075 that was very close in dimension and am sawing off a 1/2" thick piece.

Here is the template as compared to the supplied piece. Supplied piece isn't very custom, in my opinion.

Have to square up the sliced 7075 and do some milling. I'll post the print once it's finished. Overall, the piece is 76W x 42H x 12.7 D mm. Designed the top holes a little oversize, since on the mill they aren't truly vertical. Bottom mounting hole on the mill is about 0.25mm offset to the right. C'est la vie.

 

[WobblyHand]

Made the bracket and installed it. Found something else disappointing. The spring loaded plungers AND the plunger castings foul the X-axis lock levers. They interfere with the body of the lever. So this design can't work with my mill, the plunger castings will break my lock levers, BEFORE the safety switch is ever actuated. As is, there is no point for this switch.

Perhaps I can turn down the plungers a bit in their diameter. More importantly, I need to mill off the bottom of both plunger castings. If that isn't enough, maybe I can make custom lock levers. Or maybe someone can say - oh you dummy, do it this way instead...



Is this amount of rework typically necessary to do to add these power feeds? The castings are located vertically with a small key, maybe I could machine it off to buy me another millimeter of clearance.

The power feed itself is mostly ok, it does give a nicer finish, but I'm finding the full install of this feed to be a bit more of a pain that I had bargained for. Is this just tolerance stackup or something else?

Since I stated earlier that I'd post the bracket design, here is the dxf file. Built my bracket to print.

 

[WobblyHand]

I just went to the PM site and found their note that modification of the installation bracket is required. Can't say I recall seeing that when I bought the PF along with the mill, but it's ok. Making the bracket was kind of fun. I was a little surprised about the not quite plug and play nature of this installation. Or maybe it was the luck of the draw and I got dealt a weak hand. Or this is just what one gets in the machining world? Perhaps I've been spoiled by other kits of greater complexity.

(Port installation kit of air conditioning on my old Toyota truck. A huge box of parts with no instructions whatsoever. Compressors, evaporators, brackets, bolts, washers, hoses, really everything needed. Everything fit with no rework. Took me a week to install. Worked immediately. Loved that AC. That was a fun installation!)

 

[tweinke]

Just a silly idea, what about changing the locking levers out for knobs with longer shanks so that the stops will clear? I did that to my PM 727 because the lever type if mot careful would catch on the ways. I myself like the knobs better because you don't have to worry about indexing them

 

[WobblyHand]

Just a silly idea, what about changing the locking levers out for knobs with longer shanks so that the stops will clear? I did that to my PM 727 because the lever type if mot careful would catch on the ways. I myself like the knobs better because you don't have to worry about indexing them

Not a silly idea at all! Sounds more palatable than machining plungers and castings.
Upon reflection, have to say this is a great idea. Thanks!

Ordered some handles. Will have to make some collars for the handles, (very tall washers!) but that's ok. Piece of 5/8" rod turned to 13mm will clear the plunger castings (and drilled to 8mm clearance for the bolt to pass through). Encouraged to have a solution.

 

[tweinke]

Knobs feel more user friendly to me so that's why I brought it up. Sometimes we don't think about the simplest solutions even when they are in front of us. This is what makes this such a wonderful place to ask questions.