Precision Matthews PM-25MV

All things related to the Centroid Acorn CNC Controller

Moderator: cnckeith

lilb93
Posts: 153
Joined: Mon Nov 06, 2017 10:26 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 0216041209
DC3IOB: No
CNC11: Yes
CPU10 or CPU7: Yes
Contact:

Precision Matthews PM-25MV

Post by lilb93 »

Just got a Precision Matthews PM-25MV. Well actually will go to Pittsburgh on Tuesday and pick it up. Does anyone know who
Makes a really good CNC conversion for it. There are a few on e bay. Has anyone used one?

Second question is on Drive motors. Steppers open loop? or closed loop? or just go all out and get servos. Will they all work with the Acorn? Thanks.
Barnesville, PA.

I always thought it would take longer to grow old.
Centroid_Liviu
Posts: 428
Joined: Mon Jul 18, 2011 9:57 am
Allin1DC CNC Controller: Yes
CNC Control System Serial Number: none
DC3IOB: Yes
CNC11: Yes
CPU10 or CPU7: Yes

Re: Precision Matthews PM-25MV

Post by Centroid_Liviu »

Open loop or Closed loop is a matter of budget and intended task. Closed loop is always "better", but depending on what you are doing and what your budget is, it is not strictly necessary. The Acorn outputs step and direction signals. As long as the stepper drive, hybrid stepper drive, or servo drive accepts that it should be compatible with the Acorn. While you can use the Acorn with closed loop servo setups for instance, please note that the loop is only closed between the motor and the drive. The Acorn itself only has feedback for a spindle encoder. Our Oak or ALLIN1DC setups have support for a fully closed loop servo setup if that is your goal.
When requesting support READ THIS POST first. https://www.viewtopic.php?f=60&t=1043

Please ALWAYS post a FRESH report. To make a report: https://www.youtube.com/watch?v=Ecvg0VJp1oQ.

(We pride ourselves on providing timely solid technical support but, without good information we may not be able to help and/or reply until such information is posted.)
lilb93
Posts: 153
Joined: Mon Nov 06, 2017 10:26 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 0216041209
DC3IOB: No
CNC11: Yes
CPU10 or CPU7: Yes
Contact:

Re: Precision Matthews PM-25MV

Post by lilb93 »

I dont want to get to crazy, it is only a 1400.00 mill. Looking on youtube most like the closed loop with the encoder on the end.
I really dont know a lot about hooking one up but will learn have lots of time. Bought a Millport over 10 years ago with a M400 and it has never failed even once. The kids use the machines everyday and I want my own to play with. Just looking to make some parts for my 7.5"railroad gauge trains. It is going to be a learning curve. Yea I could go out and buy a Tormac but then you would not get the centroid controller and software which I really like.
Attachments
3AB8B55E-6B2D-4B9C-B475-077E2236AA8F.JPG
rsz_dsc_2583.jpg
Barnesville, PA.

I always thought it would take longer to grow old.
MecTechMike
Posts: 54
Joined: Thu Aug 10, 2017 8:59 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: none
DC3IOB: No
CNC11: No
CPU10 or CPU7: No

Re: Precision Matthews PM-25MV

Post by MecTechMike »

I have the bigger brother PM-727 for which I've converted to CNC using the Acorn and Teknic drives. The Acorn absolutely rocks. Even though the Acorn is not a full closed loop controller, I've dome some precision CNC work that measured less than 0.5 thousandth error. The Centroid fellas really did their homework on this and works right out of the box. I've gotten great support as well, and a bunch of the early adopters have posted a number of how-to videos. There's a great community building behind the Acorn.

I bought the high power NEMA 34 Teknic drives for my mill. They are solid servo motors and hold their position with authority. I currently have them set to only 20% of their full torque (haven't installed limit switches yet). For the PM-25, I'm sure you can get away with the smaller NEMA 23 for the x and y axes. For the Z-axis, it depends on the weight of the head and whether you plan to counter balance the head (which I'm doing since my head weights in at about 120lbs). I'd be safer to go with a NEMA 34 for the Z-axis.

There are other motors that work with the Acorn, but I cannot comment to their price or performance. The Teknics are hardy motors and are individually closed loop. If you go Teknic, be sure to get their power supplies as they are really designed to supply the necessary drive power to the motors.

Hope this helps,
Mike
Attachments
IMG_0815.JPG
IMG_0819.JPG
IMG_20170728_213936.jpg
martyscncgarage
Posts: 9912
Joined: Tue Mar 28, 2017 12:01 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: Yes
Oak CNC controller: No
CNC Control System Serial Number: none
DC3IOB: No
CNC12: Yes
CNC11: Yes
CPU10 or CPU7: Yes
Location: Mesa, AZ

Re: Precision Matthews PM-25MV

Post by martyscncgarage »

Do a YouTube search for ArizonaVideo99.
He makes ballscrew conversion kits. He refits the ballscrews with slightly oversize balls to help make them a little tighter. I've heard good things about David. He lives not terribly far from me. I have a G0704 that might get fitted with ballscrews. Its already converted to CNC using the original screws.

Automationtechnologiesinc.com sells closed loop steppers. I am going to try them on the next Dyna DM2400 build. I have two more to do (don't ask ;)

Clearpath makes some awesome motors and DMM Technologies out of Canada also makes some reasonably priced small Nema 23 and 34 AC servos

There is nothing wrong with open loop steppers and stepper drivers so long as they are sized and matched correctly. Geckodrive did a nice write up on that subject. https://www.geckodrive.com/gecko/images ... 0Guide.pdf

Lots to choose from! YouTuber Franco just refitted a PM25 with closed loop steppers and he just announce he is going to try the DMM AC servos and refit the spindle motor with one of them. Should be an interesting build. Check out Franco's channel.

Good stuff out there on YouTube, if nothing more than ideas and inspiration.
If you move forward, please consider posting a build progress with pictures here. We'd like to see how it goes.

Oh, the part about a $1400 mill? That is can be cheap part. :shock:
Marty
Last edited by martyscncgarage on Fri Nov 10, 2017 6:22 pm, edited 1 time in total.
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
martyscncgarage
Posts: 9912
Joined: Tue Mar 28, 2017 12:01 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: Yes
Oak CNC controller: No
CNC Control System Serial Number: none
DC3IOB: No
CNC12: Yes
CNC11: Yes
CPU10 or CPU7: Yes
Location: Mesa, AZ

Re: Precision Matthews PM-25MV

Post by martyscncgarage »

MecTechMike wrote: Fri Nov 10, 2017 5:33 pm I have the bigger brother PM-727 for which I've converted to CNC using the Acorn and Teknic drives. The Acorn absolutely rocks. Even though the Acorn is not a full closed loop controller, I've dome some precision CNC work that measured less than 0.5 thousandth error. The Centroid fellas really did their homework on this and works right out of the box. I've gotten great support as well, and a bunch of the early adopters have posted a number of how-to videos. There's a great community building behind the Acorn.

I bought the high power NEMA 34 Teknic drives for my mill. They are solid servo motors and hold their position with authority. I currently have them set to only 20% of their full torque (haven't installed limit switches yet). For the PM-25, I'm sure you can get away with the smaller NEMA 23 for the x and y axes. For the Z-axis, it depends on the weight of the head and whether you plan to counter balance the head (which I'm doing since my head weights in at about 120lbs). I'd be safer to go with a NEMA 34 for the Z-axis.

There are other motors that work with the Acorn, but I cannot comment to their price or performance. The Teknics are hardy motors and are individually closed loop. If you go Teknic, be sure to get their power supplies as they are really designed to supply the necessary drive power to the motors.

Hope this helps,
Mike
Mike you did a nice job. How do your like your mill? Enjoying the learning part of things?

Marty
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
lilb93
Posts: 153
Joined: Mon Nov 06, 2017 10:26 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 0216041209
DC3IOB: No
CNC11: Yes
CPU10 or CPU7: Yes
Contact:

Re: Precision Matthews PM-25MV

Post by lilb93 »

I did send davedaxx1@yahoo.com an e-mail waiting to hear back.
Barnesville, PA.

I always thought it would take longer to grow old.
lilb93
Posts: 153
Joined: Mon Nov 06, 2017 10:26 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 0216041209
DC3IOB: No
CNC11: Yes
CPU10 or CPU7: Yes
Contact:

Re: Precision Matthews PM-25MV

Post by lilb93 »

MecTechMike wrote: Fri Nov 10, 2017 5:33 pm I have the bigger brother PM-727 for which I've converted to CNC using the Acorn and Teknic drives. The Acorn absolutely rocks. Even though the Acorn is not a full closed loop controller, I've dome some precision CNC work that measured less than 0.5 thousandth error. The Centroid fellas really did their homework on this and works right out of the box. I've gotten great support as well, and a bunch of the early adopters have posted a number of how-to videos. There's a great community building behind the Acorn.

I bought the high power NEMA 34 Teknic drives for my mill. They are solid servo motors and hold their position with authority. I currently have them set to only 20% of their full torque (haven't installed limit switches yet). For the PM-25, I'm sure you can get away with the smaller NEMA 23 for the x and y axes. For the Z-axis, it depends on the weight of the head and whether you plan to counter balance the head (which I'm doing since my head weights in at about 120lbs). I'd be safer to go with a NEMA 34 for the Z-axis.

There are other motors that work with the Acorn, but I cannot comment to their price or performance. The Teknics are hardy motors and are individually closed loop. If you go Teknic, be sure to get their power supplies as they are really designed to supply the necessary drive power to the motors.

Hope this helps,
Mike

Mike who made your kit? I did not pick up the PM 25 till tuesday Maybe move up to PM 727. Thanks John
Barnesville, PA.

I always thought it would take longer to grow old.
MecTechMike
Posts: 54
Joined: Thu Aug 10, 2017 8:59 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: none
DC3IOB: No
CNC11: No
CPU10 or CPU7: No

Re: Precision Matthews PM-25MV

Post by MecTechMike »

martyscncgarage wrote: Fri Nov 10, 2017 6:21 pm
Mike you did a nice job. How do your like your mill? Enjoying the learning part of things?

Marty
Thanks. The mill is pretty good for the price. Good size, decent accuracy, not too noisey (hardened gears). Spindle speed is fine as a manual mill, but may be a little slow for CNC (1760 RPM's). The ways are finished well. With the gibs tight, there is very little play (1/2 thou). It's important to lock down the quill to keep the run out down. I may at some point replace the tapered spindle bearings with angular contact ones.

Definitely enjoying designing the CNC system and putting the machine together. I'm in the throws of finishing the Z-Axis. Ball screw is on back order so I gotta wait. Once that's done, I hope to tighten down everything for good.

Mike
Last edited by MecTechMike on Sat Nov 11, 2017 12:24 am, edited 1 time in total.
MecTechMike
Posts: 54
Joined: Thu Aug 10, 2017 8:59 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: none
DC3IOB: No
CNC11: No
CPU10 or CPU7: No

Re: Precision Matthews PM-25MV

Post by MecTechMike »

lilb93 wrote: Fri Nov 10, 2017 6:43 pm
Mike who made your kit? I did not pick up the PM 25 till tuesday Maybe move up to PM 727. Thanks John
I made my kit myself. I picked the PM-727 for its larger capacity, especially the z-axis (a vise and chuck take up a lot of height). The machine is about 500 lbs, so it has good stiffness. Also, the motor is 110V so it plugs in without the need to run a 220V line.

If you decide on the 727, I can help with the conversion.

Mike
Post Reply