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- Jan 26, 2021
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I've used wedge anchors many times with great results.
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Precision Matthews PM-728VT CNC conversion
- Thread starter koenbro
- Start date
- Joined
- Feb 23, 2016
- Messages
- 424
Thank you for the tip, how long and what diameter would you recommend to anchor a machine this size? Is that a non-removable anchor?
- Joined
- Jan 26, 2021
- Messages
- 344
I'm using 1/2" diameter to anchor the cabinet on my PM-833TV.
I've been told that you can drill through the slab before installing the anchor. Then if it must be removed you can punch it all the way through the slab into the ground. Just fill the hole with concrete and it's, almost, as good as new. I haven't done this but it makes some sense.
Nice conversion. I got my PM728 conversion up and running around the end of January 2020. Not complete but functional. I'm now on a tangent converting a PM1022 for CNC. I think you are all past the point I can add much but willing to help if I can. I just found your thread.
Thanks.
Hugh
- Joined
- Feb 23, 2016
- Messages
- 424
Thanks Hugh, that is very helpful (I have replied to your message).
Here is the current state of the conversion:
I do not have a proper enclosure, have put everything on a 12x12x1/16 piece of 6061, and some 3/4 angle to attach "side walls". Will cover it up with some transparent plastic. Had to remove the side wall where the aviation connectors brought the motor cables, because I rewired those. I had initially cut of the molex connectors and wired directly into the Acorn (via 7/8" 6 pin connectors), but Centroid came out with new wiring recommendatios. So I crimped back the molex spades, ditched the aviation connectors, and attached a CNC4PC ACCP board. The spindle control stil goes thorugh a 6-pin aviation conn. Will need to reconnect the sensors (M12, 4-pin aviation conns), and will rewire the e-stop to another 4 pin.
Then the KP-3 sensor (that I have on order) will get another 4-pin. Finally I haven't decided yet on a tool height sensor and am not inclined to pay another $700. Is there some easy touch-closes-circuit-trips-relay type solution? My Avid CNC router has a very elegant and reliable system, and really would want smth like it for tool height.
The motor supply will be rewired to get 220V and will get its own box.
Finally, the coolant pump, and task light will get 3-pin outlets controlled through relays. Took me a while to find the gland plate outlets (which will go to the bottom wall) but they are on order.
You will notice the illy can in which I keep the mill-specific tools, and the ADM-TPD (antigravity deceleration management table protection device, aka wood block).
Sent from my iPhone using Tapatalk Pro
Here is the current state of the conversion:
I do not have a proper enclosure, have put everything on a 12x12x1/16 piece of 6061, and some 3/4 angle to attach "side walls". Will cover it up with some transparent plastic. Had to remove the side wall where the aviation connectors brought the motor cables, because I rewired those. I had initially cut of the molex connectors and wired directly into the Acorn (via 7/8" 6 pin connectors), but Centroid came out with new wiring recommendatios. So I crimped back the molex spades, ditched the aviation connectors, and attached a CNC4PC ACCP board. The spindle control stil goes thorugh a 6-pin aviation conn. Will need to reconnect the sensors (M12, 4-pin aviation conns), and will rewire the e-stop to another 4 pin.
Then the KP-3 sensor (that I have on order) will get another 4-pin. Finally I haven't decided yet on a tool height sensor and am not inclined to pay another $700. Is there some easy touch-closes-circuit-trips-relay type solution? My Avid CNC router has a very elegant and reliable system, and really would want smth like it for tool height.
The motor supply will be rewired to get 220V and will get its own box.
Finally, the coolant pump, and task light will get 3-pin outlets controlled through relays. Took me a while to find the gland plate outlets (which will go to the bottom wall) but they are on order.
You will notice the illy can in which I keep the mill-specific tools, and the ADM-TPD (antigravity deceleration management table protection device, aka wood block).
Sent from my iPhone using Tapatalk Pro
Last edited:
- Joined
- Feb 23, 2016
- Messages
- 424
They came with the PM CNC conversion kit.
- Joined
- Feb 23, 2016
- Messages
- 424
I need some advice re: base fabrication.
I have some leftover 2x1x1/8" steel channel I want to get rid of, so that s my first choice, unless advised otherwise. I will have corner braces to stabilize the structure at the top, one shelf for the coolant pump, and a second one for a drawer, and plates at the bottom to screw anchors into the floor. Plan to weld the rectangular top together, flat and square, but the legs will be screwed to the top for dampening. The shelves will also be screwed to the legs.
Second, I plan to add a coolant tub, which will have to be about 53" wide and 28" deep. Side walls for the enclosure will be made of 8020 1010 sticks.
Should I make the base just to support the mill, like in the rendering above, or should I bring the front all the way forward under the motor ( the protuberance at the front is the y servo motor, which sticks out 7 1/2" from the base casting)?
I am at an impasse and need your advice with the above.
koenbro asked about my PM728 conversion in a PM. I thought it may be of interest to others so I'll post here.
I used the PM kit as everyone here has. It went together very easily, with the only disassembly to pop the head off letting it sit on the table. I used steppers from Automation Technologies, NEMA 23 for X & Y at 425 oz-in and a NEMA 34 for Z at 920 on-in. I found versions with the correct shaft size for the PM shaft connectors. I'm driving these with Gecko G201X stepper drivers and a 70 VDC 1000 watt power supply from Antek. They seem to work well together and have adequate power and speed. I use LinuxCNC paired with an internal Mesa 5i25 card and a Mesa 7i76 breakout board. The computer is a small (I think miniITX) carried over from a Sherline conversion.
I, as yet, have no limit or home switches. I set the machine to its home position manually (jogging) and tell the machine it's home when I start it up, as needed. But generally when I power it down I park the axes at home ready for the next start-up. For this given home position I depend on software limits rather than switches. Not adequate for a commercial product, but for my personal hobby machine it works well for me.
No electronics box yet. I did size the plywood the components are mounted on to fit a standard box though. There's a small relay board at the top (not yet connected) for coolant, etc. I'm not sure if the electronics will mount on the side of the stand or remain on the wall. Time will tell. I bought a CNC speed control board from PM but haven't hooked it up yet. May be nice but speed control from the G-code isn't critical to me.
I built a wooden stand as shown in the picture. It works well and gives some storage. I should have put a solid partition in the middle for support rather than the full width drawers. It sags enough for the top drawer to drag. Will likely be addressed next fall. I built a wooden chip box to catch most of those nasty chips. I did the same on my knee mill and it works very well there. However on the PM728 the shape of the head runs into the box more readily. It's a nice simple solution but I may have to build a full enclosure. I use mist coolant so the box, or enclosure, doesn't have to be water tight.
I hope this gives some idea of my conversion. I'd be glad to address any questions you might have. Thanks.
Hugh
I used the PM kit as everyone here has. It went together very easily, with the only disassembly to pop the head off letting it sit on the table. I used steppers from Automation Technologies, NEMA 23 for X & Y at 425 oz-in and a NEMA 34 for Z at 920 on-in. I found versions with the correct shaft size for the PM shaft connectors. I'm driving these with Gecko G201X stepper drivers and a 70 VDC 1000 watt power supply from Antek. They seem to work well together and have adequate power and speed. I use LinuxCNC paired with an internal Mesa 5i25 card and a Mesa 7i76 breakout board. The computer is a small (I think miniITX) carried over from a Sherline conversion.
I, as yet, have no limit or home switches. I set the machine to its home position manually (jogging) and tell the machine it's home when I start it up, as needed. But generally when I power it down I park the axes at home ready for the next start-up. For this given home position I depend on software limits rather than switches. Not adequate for a commercial product, but for my personal hobby machine it works well for me.
No electronics box yet. I did size the plywood the components are mounted on to fit a standard box though. There's a small relay board at the top (not yet connected) for coolant, etc. I'm not sure if the electronics will mount on the side of the stand or remain on the wall. Time will tell. I bought a CNC speed control board from PM but haven't hooked it up yet. May be nice but speed control from the G-code isn't critical to me.
I built a wooden stand as shown in the picture. It works well and gives some storage. I should have put a solid partition in the middle for support rather than the full width drawers. It sags enough for the top drawer to drag. Will likely be addressed next fall. I built a wooden chip box to catch most of those nasty chips. I did the same on my knee mill and it works very well there. However on the PM728 the shape of the head runs into the box more readily. It's a nice simple solution but I may have to build a full enclosure. I use mist coolant so the box, or enclosure, doesn't have to be water tight.
I hope this gives some idea of my conversion. I'd be glad to address any questions you might have. Thanks.
Hugh
I'd vote for some cross bracing on the sides and back. You could weld the sides up with bracing then bolt to the top with bolted cross bracing on the back.
I think you're planning on an enclosure? If so then plan for this as you build the base. The enclosure could just extend past the base, or the base could extend far enough to be part of the enclosure. Lots of details to consider, but think about the enclosure as you design the base. Just me two cents worth.
Thanks.
Hugh