New PM-25MV Mill

Its upgrade time! I've got some new parts coming for the mill so I figured I would post a quick update, as well as summarize the costs for everything so far in case anyone else is looking to go the same route.

Parts and costs all including shipping:
2 400 oz in Nema 23 steppers - $67
1 1000 oz in Nema 34 stepper - $69.79
2 DM542T stepper drivers - $67.90
1 DM860T stepper driver - $53.95
1 550 mm SFU1605 ballscrew - $65
1 750mm DFU1605 ballscrew - $50
1 350mm DFU1605 ballscrew - $50
6 7001 AC bearings - $15.54
3 flexible couplers - $15
4 inch mill vise - $100
PM-25 mill - $1649
350 watt power supply - $30
240 watt power supply - $20
Break out board - $10
Aluminum stock - $10
Total - $2271.18

I am hoping to install the new drivers today. I am hoping they run much smoother than the TB6600s. I think the ballscrews are supposed to be delivered tomorrow, so I will update once I figure out if they are any good.

For the tool changer, I have a piece of 4 inch aluminum bar 8" long being delivered tomorrow to make an air cylinder. I also have 36" of 12L14 steel for tool holders coming. The mill will probably be used in lathe mode to make most of those. I also made the umbrella a little bit bigger to hold 12 tools instead of 10.

I also finished the first part CNCd part made on the machine. I got the backlash figured out and I got the X axis to stop losing steps. It is the electronics box for my micro lathe. This machine really can rip up some metal.
qfE6MZD.jpg

bDKNma2.jpg
 
Its upgrade time! I've got some new parts coming for the mill so I figured I would post a quick update, as well as summarize the costs for everything so far in case anyone else is looking to go the same route.

Parts and costs all including shipping:
2 400 oz in Nema 23 steppers - $67
1 1000 oz in Nema 34 stepper - $69.79
2 DM542T stepper drivers - $67.90
1 DM860T stepper driver - $53.95
1 550 mm SFU1605 ballscrew - $65
1 750mm DFU1605 ballscrew - $50
1 350mm DFU1605 ballscrew - $50
6 7001 AC bearings - $15.54
3 flexible couplers - $15
4 inch mill vise - $100
PM-25 mill - $1649
350 watt power supply - $30
240 watt power supply - $20
Break out board - $10
Aluminum stock - $10
Total - $2271.18

I am hoping to install the new drivers today. I am hoping they run much smoother than the TB6600s. I think the ballscrews are supposed to be delivered tomorrow, so I will update once I figure out if they are any good.

For the tool changer, I have a piece of 4 inch aluminum bar 8" long being delivered tomorrow to make an air cylinder. I also have 36" of 12L14 steel for tool holders coming. The mill will probably be used in lathe mode to make most of those. I also made the umbrella a little bit bigger to hold 12 tools instead of 10.

I also finished the first part CNCd part made on the machine. I got the backlash figured out and I got the X axis to stop losing steps. It is the electronics box for my micro lathe. This machine really can rip up some metal.
View attachment 262219

View attachment 262220

That's an awesome looking box! Keep up the good work!

PZ
 
I got the ballscrews in, but all I will say about them is that they are not good. I won't post any more details until I have sorted out the issue with the seller.

I made new pulleys for the spindle and motor to speed it up. I managed to get it to about 5450 RPM. It sounds better than it did before and I did a few test cuts and it ran very well. After about 30 minutes of cutting, the spindle was very hot though. My laser thermometer read about 140 degrees F. I will likely need to swap those out for some AC bearings in the near future. That was the plan anyway so I am not worried about it. There was no slipping of belts even in the heaviest cuts I tried. I actually managed to get the axis motors to stall before the spindle motor stalled. It was able to take several very stout cuts without any issues. I will definitely need an enclosure soon because it was chucking chips easily 10 feet away. I am currently looking for a new spindle motor for the machine to get a bit more torque and speed it up a little bit more. It has a 2500 RPM motor, so if I can find one that will do 4000, the spindle will run just under 9000 RPM. The current motor is doing ok, but it takes too long to catch up to torque requirements during heavy cuts. I think I will end up using that motor on a lathe I am designing and get a new one for the mill.

I am also working on machining the air cylinder for the auto tool changer. I have made most of the parts for it, I just need to order some components for it before it will be ready to use. I have the design for mounting it and the spring washers all set out, and I will be using the new 5500 rippems to make the parts. I should be able to get 2300 lbs of force from the air cylinder and the springs will be arranged to give me about 1900 lbs of holding force. I am hoping that will be enough. If not, I can get some stronger springs and increase the pressure in the air cylinder. I did take some ideas from The GRIZZ build over on CNCzone, so if it looks familiar, give them credit, they gave me the idea. I have stock for the tool holders, but I have not had a chance to machine them yet. They are going to be very similar to TTS holders and are going to be made from 12L14. If that ends up not being enough, I will make new ones out of 4140. I am a hobbyist though, so I doubt they will see enough use to be worn out.

For the enclosure, I am trying to decide between MDF and sheet metal. I have zero experience with sheet metal and I have none of the equipment for working with it, so that might be a problem. But I also think sheet metal would work better and would be much nicer. I have gone back and forth on that. I have always wanted to do sheet metal stuff, so a massive first project to learn the ropes might work, right?

I am still loving the machine. My 2 PM machines have just about filled a 35 gallon trash can with aluminum chips. From what I have seen this machine do in the last few days, I have a feeling that problem will only be getting worse. Here are some pictures.

63lHSRo.jpg


CQ7Ig7d.jpg


FsvJMOV.png


SFwHpFE.png
 
Really nice looking work!

Where did you order your ball screws from? I'm starting to design a router and any input/advice on that front would be much appreciated!

PZ
 
Really nice looking work!

Where did you order your ball screws from? I'm starting to design a router and any input/advice on that front would be much appreciated!

PZ
I got them from linearmotionbearings2008. I won't go into details until the whole thing is settled, but I would not recommend.
 
Great thread!! I have a new PM-25 ordered that is suppose to be here in a couple of days. A CNC conversion is possibly in the the future, but initially I want to use the manual machine to learn on. (My first milling machine)

Since available help with a strong back and weak mind is in short supply, I have been trying to calculate how I was going to get it from the shipping container up to the bench top!! Now I know. I opted for terminal pickup so having the shipping company load to the back of my truck will take care of half the battle.
------

When you ordered the PM25- Did you consider the DRO upgrade they offer? I assume there are cheaper DIY scales and read outs, but the one offered looks to be specific to this mill with a larger read out panel. Only down side appears to be conflicted space with the z axis handles at top right of the column?

Has anyone had experience with the PM installed DRO, and is it worth the extra cost ?

Last time I checked the DRO upgraded unit was not available, so have some time to think about it- or just order a basic mill ?

PM customer support seems to be well regarded, but wonder if actual users think the extra cost is worth the wait?

Thanks,
 
------

When you ordered the PM25- Did you consider the DRO upgrade they offer? I assume there are cheaper DIY scales and read outs, but the one offered looks to be specific to this mill with a larger read out panel. Only down side appears to be conflicted space with the z axis handles at top right of the column?

Has anyone had experience with the PM installed DRO, and is it worth the extra cost ?

Last time I checked the DRO upgraded unit was not available, so have some time to think about it- or just order a basic mill ?

PM customer support seems to be well regarded, but wonder if actual users think the extra cost is worth the wait?

Thanks,

I didn't really look at the DRO upgrade..... Tight budget just to get the machine (my first mill as well) restricted how much I had to spend initially. I've had only limited contact with support as yet.... my experience and everything I have read across the web is positive. The first thing I decided that I would really need is a power lift for the head assembly. I have all the parts to do the upgrade now..... just need to fabricate a mounting for the motor and wire it up.

Most all of what I anticipate using the machine for is pretty basic. The DRO would be overkill for me I think, but the addition of a horizontal feed is looking more and more likely as I surf the web for instructions. A downturn in health is keeping me out of the shop for now, but hopefully that will change soon.

Hopefully someone else with DRO knowledge will chime in soon and answer your other questions.
 
Back
Top