PM-25MV full review w/pics

A few weeks back, I ordered my very own Precision Mathews PM25-MV. I spent a few months planning my purchase. I needed a mill, big enough to handle a lot of aluminum, plastic and other non-ferrous materials. Light random pieces of steel were also a possibility. Generally I believe in the idea of "buy the biggest thing you can afford". Sometimes this doesn't always apply.
I should start by adding in what my credentials are in regards to the review. I have spent the last 12 years as a machinist. I began on manual Bridgeports, and then took over running the CNC department that consists of 2 VMC's and a 5 axis router. 90% of what I know, is self taught. With that said, any specific machining tactics can be taken with a grain of salt.
The criteria. I have simple needs in the short term, but also required adaptability. The plan was to use the machine manually for a while, and then upgrade to CNC in the near future. With access to much larger machines at work, I needed something to fill the gaps with personal projects at home. Largest items I make usually require 1/2" cutters and below. I don't need high volume material removal either. CNC adaptation or pre-built was required.
The competition. Here is the list of the 5 top runners for the purchase:
1. 2HP J Head Bridgeport
2. Tormach PCNC 1100
3. Grizzly G0704
4. PM25-MV
5. PM-727M

My choice: I chose the the PM25-MV over the others for many reasons, but the first hurdle is always budget. The budget is what killed off the Tormach. That will always be my first choice, and may someday make it's way into my shop anyway. After that, was power. I don't have, nor can I afford 3 phase power, so the Bridgeports were off the list there. I could have opted for a VFD control, but again...budget. Tht left me with the last 3. The G0704 is insanely popular, and fit the budget. However, Precision Mathews has done many upgrades to the PM25 that are pretty much necessary immediately with the G0704, so then it was down to two. In the end I almost purchased a 727M and for the extra cost you get much more weight, which is always good for rigidity. Basically it came down to a coin toss, ship dates, and a few hundred dollars. I am happy with the choice.

Onto the review. I'll start with the ordering and shipping. Knowing as much as one can know after all my research and my prior experience I didn't need to spend much time on the phone, so the order process was extremely fast and simple. I made my call on Friday afternoon around 2pm. By Saturday morning I had a tracking number and shipment confirmation from Ward Trucking. To make things easier for me, I had the machine shipped to work for easier truck access. By Monday afternoon at 1:30pm, the crate was sitting in front of me. Wow. I should note...PM is in Pennsylvania, I am in western NY, so it's not far, but still...that's fast service. The crate arrived in mint condition, with the plywood box nailed and bolted to a pallet.

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Setup. It should be noted, to get the machine home, I separated the column from the base into two pieces. I then built a base frame from extruded aluminum Framing Tech, hoisted the base onto it and bolted it down. After that I carefully placed the column back on and snugged the 4 bolts. The first step was to check the tram of the spindle to the bed and tighten the column screws accordingly. Well...that was simple. The head nod (front to back) was dead on perfect. Side to side was as well. Using an indicator and a precision square, the spindle was so close to perfect I gave up looking for the flaw. I adjusted the gibs a bit to add a little tension and threw a vice on it. After the standard vise tramming, I was technically ready to make chips. However, since I am a bit of a tinkerer, I ordered a 2 axis Igaging DRO kit, some R8 tool holders and a light.

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Overview of fit and finish. I'll start with the negatives since it's a short list. The machine looks fantastic. The blue and white are great. The paint is thick but the white coating on the casting flakes easily around edges. After everything was setup, I found a lot of chips littering the tray and floor. Not a lot, but a little here and there. After that, I would add the Y axis locks as the other negative. This is very minor considering the required location and use. They are just a pain to use. It's tight in there and I always end up with grease from the ball screw all over my hand. It's not a deal breaker, and once the CNC conversion happens, it doesn't matter.

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The dovetails are beautiful. This is one reason I chose it over the G0704. Many people mentioned the attention to these, and it shows. I've seen Bridgeports with uglier dovetails. All the axis move smoothly, without any tight areas or sticking. There is a slight tightness noticed if the Y axis is locked and you traverse the X axis due to over tightening. When you raise or lower the head, it's smooth, and very easy. If I was not planning to CNC, I would probably opt for a motorized head conversion just to make things easier. With only 2" (50mm) of spindle travel, you move the head a lot. Once I had a chance to dial in the DRO's and test, I found the accuracy of the machine/DRO combo to be well within expected tolerance. I work in large numbers so generally anything for me within .003" is plenty accurate, and this did that easily.

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My initial use had some delays and concerns which were mostly in my own head. As with most things, a warm up and break in period is required for the machine. I spent some time running through all the speeds and wait times...basically I spun the machine in increments of 500 rpm for 10 minutes in both directions, did some cleaning, spun some more. At first it seemed odd, it never reached it's max speed of 1250/2500, and the speeds it did reach, took a long time to get there. As it turns out, there is a bit of a soft start built into the board, so it works much better if you adjust the speed dial, and then just turn on the machine...sort of like a Bridgeport. Once I was satisfied the motor and bearing were broken in, it ran smooth. When you hear that the belt drive is quiet, it's more accurate than expected. Running full speed at 2500 RPM, I can talk normally, and clearly hear the tv at normal volume behind me. It's weird, but it's nice. Just a steady whirring and the sound of the cutter making chips.

I should also mention one other thing that could be a negative. The drawbar. The drawbar design is awful. It's just bad. I would not hold it against PM, but perhaps suggest a different design for the top. The top of the drawbar is an 8mm square. In order to remove a tool, you hold the spindle with the included spindle wrench, then loosen the drawbar with the 8mm wrench. It's tedious. So, I cheated, and will become a future feature I am building. There are many designs for air operated power draw bars, but I would much rather not use air and press in the spindle, so I opted for an electric impact wrench. A simple 1/4" impact gun with a cut down 9mm Kobalt Universal Socket does the trick one handed.

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Below are some test passes I ran by hand. I used the following setup to do it: 1/2" 2 Flute end mill. 1200 RPM, 1" depth, .05" WOC. Feed was...by hand.

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Bang for your buck value of the machine is fantastic. Despite the flaws, which I must say are minor, this is a very capable machine. If size, power and budget limit you to a benchtop unit, this one wins over the others. With some careful adjustment and planning it's a great machine for a lot of material. I have not put any real quantity of steel through it, but with everything locked down I am sure it will perform well enough to get the job done. The belt drive upgrade is perfect and the motor is quiet and stays cool even at low speeds. As a side note, when choosing a vise, i just had PM send me a 4" with the machine. You might find the Z height a little small if you opt for the swivel vise, but that can be remedied easily by removing the swivel.
In the end, do I have any buyers remorse. Absolutely not. Would I buy again. Of course. Would I recommend this machine to others looking for something of this size. Yes...go buy one.

I will update this review as things progress or change.

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That is a nice stand for the PM25MV! Where did you get it?

about two weeks ago i received a new PM25MV as well. It's a great little machine for the price. I was by myself getting it onto the stand so I took off the column and head. One thing I noticed while I did was that the base is hand scrapped where the column mounts to get the alignment. Now that said, the column was still out about .005" over 8" in one direction and about .003" in the other. Not to shabby for a banchtop.

I built the stand out of material from here: Framing Tech

What DRO kit did you install? I have a PM-25MV on the way and would like to order up the DRO set you have. I checked amazon and all I see is 6" 12" and 24". it looks like the X axis would need to be a 30" or so. can you share a link to what you purchased?

Thanks,
Tim

Absolutely. Here is what I purchased. I can take more specific pics of how it's mounted. I didn't want to have to go all crazy with mounts and things, so I only had to drill a couple holes in the casting. I still need to make some sheet metal covers for them to keep the chips off.

12" Igaging
Amazon.com: iGaging 12" Magnetic Remote Digital Readout: Home Improvement

24" Igaging
Amazon.com: iGaging 24" Magnetic Remote Digital Readout: Home Improvement


I also have recently ordered a VFD and motor. I wanted more power for some steel work I've been getting lately, so I'm upgrading to a 2HP C56 motor. Once that upgrade is done I will update the thread.

Great! thanks for the quick reply

I haven't mounted the iGaging scales yet, but I got and built the following:

How to Build the Mixed Scale Digital Readout Kit | Yuriy's Toys

It's a board that reads the scales and transmits their readings via bluetooth to a free app on an Android tablet. The kit was pretty easy to solder up, and other than me brain farting and missing one resistor, worked first try. On the bench, it works great and should be much easier to read than the included LCDs.

I feel the same way about this machine, currently machining out a cnc conversion for mine.

Had the hit the spindle wrench with a hammer a few times to reduce the play, will probably use a 1/4" impact and put the wrench back in the tool box though.

Sears has a 8 point socket set with a 5/16" which is close enough to 8mm.

When you guys run the spindle at about 1500 rpm for a few minutes, does the spindle get too hot to touch (or at least very uncomfortable)? Mine does, and I wonder if that's normal or if it needs adjustment, or there's a problem...?

Mine gets warm but not too hot, although I haven't ran it too much other than the break in. I have probably ran it for 45 min total at full rpm.

I have heard of machines running hot for the first 10-20hrs and then they cool down. Guess that's how they break in. I don't think there is any adjustments as far as spindle bearing preload but I am not totally sure.

Tim

Quote:

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Originally Posted by yohan

When you guys run the spindle at about 1500 rpm for a few minutes, does the spindle get too hot to touch (or at least very uncomfortable)? Mine does, and I wonder if that's normal or if it needs adjustment, or there's a problem...?

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I would agree. It depends on how much you have run it. I would say mine got "pretty warm" fr a while, but I am quite far past break in at this point. and I have run the spindle up around 1800 for 20min at a time with no real bad heat. It still gets warm, it always will. If it is truly HOT then i would take a look at the bearings.

I finally pulled the trigger on getting one of the big 3ph autmation direct motors and VFDs so that will be a project soon.

The spindle pre-load is adjustable, There is a threaded collar that contains to socket head capscrews that must be loosened so that the collar can be un-threaded from the spindle. A spanner wrench will be necessary to properly tighten the collar. If the spindle is heating (mine did too)there is too much pre-load on the bearings. This is covered in the owner's manual.

it's been five years since you bought the PM-25. Can you give us an update? Thanks!