Centroid Community CNC Support Forum

Hello,
I purchased a 1997 Milltronics VM17-B milling machine center. It has a 20 station ATC, a 10hp spindle motor controlled by a Hitachi WJ200-075LF VFD, and Yaskawa drive systems on the 3 axis’s using Servopack SGDB-10ADG amps. The antique control boards went bad and the owner was going to retrofit with MESA cards, but it was beyond his ability. He included a ACER touchscreen monitor and a Lenovo Thinkpad computer, an American Rotary AD rotary phase converter, running a 20hp Baldor motor, and two 6” New Kurt vices. I paid $1800 because he is getting a divorce and the mill must be moved.

I was planning on buying a bench top mill or even considered just mill castings and do a total build, but couldn’t pass this deal up for the price. The machine is tight and doesn’t appear to ever have been used much. All ball screws are good, linear rails and carriage blocks are tight, and no visible damage that I can see.

This retrofit will be a complete new install. I’m removing all the components in the enclosure, replacing all the servo cables, and installing new limit switches. I’m taking it down to just the castings, spindle and motor, and servo drives, so I can do a clean retrofit. I plan on removing the ATC and flood coolant, as I don’t have a need for them.

The recommended Centriod Board is the OAK, but I have chosen the Acorn since this will be a very basic 3 axis machine. I have the board, the MPG pendant, the pro software and an encoder cable for the spindle. I have read, and searched the success stories section, but don’t see any examples of anyone else doing this. Was hoping there was someone out there who could share in my upcoming adventure.

Even though I believe the OAK board is overkill, is there a reason I’m overlooking that the Acorn won’t be a good fit for this retrofit? Any advice, info, links to videos snd other information is appreciated. I have a CNC Shark, CO2 and Fiber laser, so I have a working knowledge of CNC, logic controls, and positioning systems, along with a proficient knowledge of electricity, but my actual electronic circuit knowledge base is not extremely strong. Please feel free to offer advice, tell me I’m stupid, or offer sympathy for this project. Merry Christmas.

Well,

I would not remove the ATC. If it was functional before LEAVE it. Identify the wiring, my guess is at some point you will want the ATC. Umbrella changers are pretty simple.

I wouldn't use Acorn on a VMC. Could you? Yes, You will need at least one Ether1616. There is some tiny latency with Ether1616. You really need to write down all the inputs and outputs you are going to need.

Find the manual for your Yaskawa drives, they may take step and direction if you decide to move forward with Acorn.
Marc or Tom may chime in because I don't have experience with the Yaskawa drives, but if they will run single phase. I would run the control on single phase and just the spindle drive and spindle on generated 3 phase from the phase converter.

You will probably need help with the PLC to control the changer with Acorn. Where with OAK there is already umbrella changer PLCs.

If your Yaskawa drives take Step and Direction, why not give it a try. You could always upgrade to Oak later...
I think you did well on the price if the machine is decent.

See if your drives take step and direction, run it with Acorn for the time being, but I would not remove the changer or drawbar sensors, ATC sensors etc. You will probably want that changer in the future.....

My .02
Marty

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I notice you have another thread going....you really should stick with one thread with all the details about the machine and build. When you ask for help, many times we go back through the thread refreshing ourselves with what you are working with.

Thank you for your reply. I’ve followed your videos on YouTube and they are great. The Yaskawa drives do accept step/ direction but I have to reduce the input voltage to 5 volts. This machine is going to be used as a gunsmithing mill to cut sight bases and dovetails, along with some pistol slide mods. That is why I was thinking to ditch the ATC, plus I have a buyer for $700. I plan on upgrading to a newer VMC in another yr, so this is just being used to learn on and knock out some basic work.

My Yaskawa’s are 3 phase input/output so that puts me powering them and the spindle by the phase converter. I originally planned on new servos and a 5 hp motor so I could use single phase power.

I was going to delete the other post but don’t see how to do that. I started this post since it’s about general machine retrofitting and the other was Yaskawa specific. Thanks again and I look forward to learning more from all the seasoned forum users. Merry Christmas.

I would keep the VM17 in tact. But its your machine to do what you need to do.
In the end you would have a simple bed mill. If space is a premium, you could remove the enclosure as well.
To me, the only issue is the high voltage spindle motor and drive. You can replace both and get it going....

Good luck!
Marty

Thank you. I’m kinda like congress... I’m saying one thing now, but who knows what the final outcome will be when it’s all done.

I would keep the ATC and get it working. A fully functioning VMC with tool changer that runs on 240v single phase has a decent market price. Guys want them for their garages.

Thanks. Unless I change the servo amps and spindle motor, I’m stuck with a 3 phase machine, but I have the 20 hp rotary converter to power it all. I’ll make up my mind about the ATC when I get it here on-site. My usage really doesn’t require it, and I’m pretty confident it will always live here, even when it gets replaced with a newer VMC. My dream is to teach others the basics of CNC so they are more employable.