# Pm25 power z axis



## OldJoe (Jan 24, 2019)

Hi everyone I wonder if anybody is interested in designing or refabricating a nice power Z axis for my p.m. 25 I just don't have the time to do it and cranking this thing is really getting old if anybody is interested please let me know. 203-2885832 

Thanks!


----------



## T Bredehoft (Jan 24, 2019)

Are you moving the head, for repositioning, or the tool , for cutting? 

I  powered the head, wouldn't want to use it for cutting, the gib is loose. 

I've seen a motor, built onto the side of the head driving the  quill. Isthis what you want?  I built a small handle attached to the face of the quill knob, works fine for boring. I   crank it, rather that twisting the knob.


----------



## OldJoe (Jan 24, 2019)

Hi thanks for your reply.  I'm simply wanting to reposition the column crank handle for height adjustment so I  can change tools, or change proximity from ... for example, drill head to end mill. Never for use as feeding a tool.

I modified the crank handle so I  would gain some leverage,  and once in a while I use a drill with a socket on it.  I have terrible rotator cuff and arthritis in both my shoulders (don't get old )   Anyway, I saw a few nicely done motor attachments shown here, and wow... pushing a button or a switch would be wonderful!


----------



## T Bredehoft (Jan 24, 2019)

Obtain a heavy duty (van or truck) windshield wiper motor* and a 12 volt power supply (old computer, battery charger, etc) fabricate a connection between the motor and the  lift crank shaft, and a mount for the motor, wire a switch through a center off Double pole double through toggle switch, and go to town. 

My motor had two speeds, I wired in a switch to toggle between high and low speed, never use low. 

Don't forget to loosen gib clamps. And tighten them again. 

* for all I know, an electric window motor would work as well, I have one driving my X feed.


----------



## OldJoe (Jan 24, 2019)

Yes, thank you for your replies.  I'm  aware of these options, but honestly, as I  asked... I'm  looking for someone with not too much on his or her plate, who has done this successfully and has the time to duplicate and sell the product to me done,  as I just don't have the time to get this done before my arm falls off from the existing small jobs I have going.  Or, point me in the direction of something done that would work.  I know nothing about CNC, but are there stepper motors available that bolt up to either the crank or on top to adjust the Z axis height?


----------



## mcdanlj (Jan 25, 2019)

Just to help you look for a thing likelier to exist: Stepper motors are relatively low on torque; it's kind of a tradeoff. My PM-30MV takes about 20 in/lbs, which would be 177 Nm or 320 oz-in, to raise the head. Your PM-25 might take a little less, but that's probably the right ball park. That would require a large stepper (on the large side for NEMA23), expensive stepper controller (like a gecko), and probably a 36V or 48V power supply, as well as a stepper motor controller—or use a gearhead stepper which will crawl so slow that you will throw it away. DC brushed motors will be cheaper and require a lot less supporting circuitry.


----------



## OldJoe (Jan 25, 2019)

Ah... thank you, so back to the drawing board.


----------



## mcdanlj (Jan 25, 2019)

Stepper motor is a minor point I think. Just pointing your searching in other directions.

When it comes to price, I noticed that grizzly sells a power lift for the G0709 for $329. It bolts onto the top and appears to drive the Z lead screw directly. It probably has a gear head. I have no expectation it would work on your mill, but it gives an idea what an inexpensive (relatively speaking) mass-produced option costs. Of course something bespoke is likely to cost more.


----------



## OldJoe (Jan 25, 2019)

Thx.  When I  search the g0709 comes back as 14x40 lathe.  Do you happen to have a link to this motor lift?


----------



## mcdanlj (Jan 25, 2019)

I accidentally typed the model number for my lathe. Griz model numbers make no sense to me. G0704 power lift was what I meant.


----------



## ConValSam (Jan 25, 2019)

Welcome!

Little Machine Shop sells a power lift for their bench mill that might work.  The LMS 5500 and PM-25 share very similar column and crank layouts.

https://littlemachineshop.com/products/product_view.php?ProductID=5657&category=2122081966


----------



## OldJoe (Jan 25, 2019)

Thank you all for your help and suggestions, I will contact LMM and ck on 704


----------



## OldJoe (Jan 25, 2019)

Thanks all, believe it or not, I went to the link for the grizzly, found the installation instructions, located the company name that made the power lift, Priest Tools.  I spoke to Greg Priest. You should just click on the Precision Matthews link, because I make one specifically for the Precision Matthews pm25 he said! That was easy!  I told him I was like a kid in a candy shop. I just ordered it.   Now we'll see how it does, it should be just fine.  Thanks again to everyone!  This should make using the machine so much easier for me.


----------



## mcdanlj (Jan 25, 2019)

Good sleuthing! In case anyone else sees this thread and is looking for the specific link, that's Power Lift Precision Matthews PM-25MV at Priest Tools.


----------



## OldJoe (Feb 5, 2019)

Well, I got my delivery today, I purchased to power supply enclosure also.  It all went together easily.  I'm kind of meticulous, so it took me about 50 minutes.  When I finished, I plugged it in, hit the switch, and up and down it went.  I thought I was in heaven!  ( if you knew how bad the pain in my shoulders was, you'd understand)  and if Greg Priest knew, he could have charged me double!  . Im happier than a pig in sh#@


----------



## 7milesup (Feb 5, 2019)

Well that was quick.  Glad you like it.  
I had rotator cuff surgery at about age 49.  Before the surgery I couldn't even get my arm up to brush my teeth.  Long recovery after surgery but it sure feels good.


----------



## OldJoe (Feb 6, 2019)

I hear so many horror stories about the surgery that I keep putting it off.  Of course, everybody told me horror stories about getting married 45 yrs. ago, but I did that anyway. Im gonna have to get it done, its both sides and its even tough sleeping.

Anyway, back to this power lift.  I love it, I'd buy it again.  But I personally would have done one minor modification if I were to have the installation to do over again.  In fact, I  might take it apart someday and do it regardless of it working fine.

There is a two piece hub with an allen set screw on each one. One half goes on the dc motor shaft, which has a flat on its shaft and the other one goes on the lead screw after removing the nut.  If I had to do it over again before I put that Hub over the threaded lead screw shaft,  I would drill and tap the Hub for one more Allen set screw and double up on them.  The hubs are connected to each other with a rubber spider that helps ease shock and prevent the two hubs from wearing against each other.  It seems a big task for that one little set screw to hold rotation against that lead screw thread for the Z axis. Time will tell I  suppose, and either way, adding one more or even two set screws,  120 degrees apart is no big deal. I am very happy a pre-made solution to cranking that damned Z axis was available. Thanks Greg!


----------

