Matter of interest

[Sudsy55]

Well, he did say:

TRA31 & 41 axis drives and FRSE spindle drive

TRA31 and TRA41 appear to be Mitsubishi servo drives, presumably original from 1986 (the date he gave for the machine). He said they are DC drives.

If I had to guess, I would say the motors have analog tachometer feedback to the drives, and resolver position feedback to the CNC. It is possible, however, that they have encoders.

It is possible that the old drives could be used -- they are almost certainly +/-10V analog velocity-mode drives. They would not necessarily perform that well, but they might. If position feedback is via resolvers, then you would have to figure out how and where to install encoders. Overall, using the old drives is likely to be more trouble than it is worth unless you are an electrical engineer with time on your hands.

It is possible that the old servo motors could be used, without the old drives. Maybe it could be done with an All-in-one DC unit, but more likely it would require Centroid's AC/DC drives. That would depend on the current draw (rated power / size) of the motors. It would again be necessary to install digital encoders on the back of the motors, but at least you would not have to retain the old tachometers there.

The path of least technical resistance would be to find out, or estimate, how much servo motor power and/or torque is required, and install new servo drives and motors. That would, of course, cost more money up front. It might end up costing less in the long run.

Using the old AC spindle drive is much more likely to be workable. That does not need to be as responsive as the servo drives. You just need to figure out what the input and output signals are (command to run forward and reverse; command to orient; optionally command to reset faults; status output for drive ok/fault; and status output for orient complete; and analog voltage input for the velocity reference). If you are lucky, those signals are shown in your original wiring diagrams for the machine. If not, you will want to see if you can locate a manual from Mitsubishi for the spindle drive unit.

This would be a pretty challenging project if it is your first CNC retrofit. Again, unless you are an electrical engineer with lots of time on your hands, be prepared and willing to hire help from people who have done it before. The research and planning required for a project like this is beyond the scope of what you can expect people to volunteer in a free support forum.

Thanks for your reply. I was just interested to know if any one had done one. Wasn't asking for help at this stage but thank you for the insight. I was thinking of the Allinone and using my original motors. Yes it has the tach gen on the motor and encoder on the ballscrews. Original spindle drive and motor would probably be kept. Just all in the thought stage for now

[martyscncgarage]

Can you give us some info on the motor and drives is currently equipped with? The best option is to take a picture of the data-plates on the motors, drives, and spindle motor , make a online photo album of with tons of photos of the entire machine and then we can comment on how to proceed.

Well first of all i didn't ask how to proceed. I am quite capable of working that out. All i asked was if anyone had done one as a matter of interest As the heading states. Secondly i did say they were tra 31 and tra 41 drives which are Mits and YM control which is also Mits.

You knew that they were Mitsubishi, you assumed we did as well. I'd never seen the control before, didn't know the make and model of the drives and motors, that's why we asked for more information and pictures of the drives and the control cabinet. Marc gave you your answer. Good luck with your decision. I wish you well in whatever you decide to do. Centroid controls are very robust. Installed correctly, they'll give you years of good service with modern features.
Marty

[cncsnw]

I was just interested to know if any one had done one. Wasn't asking for help at this stage but thank you for the insight.

Put that way, I suppose the comparative lack of replies could have been interpreted as "no, no one here has retrofitted an example of that particular machine".

However -- and this should be taken as general advice for the many people who come here with similar questions -- it is not especially likely, and not particular important, that someone else has retrofitted your particular make and model machine before.

There are thousands of different machines out there, and unless you are doing a Bridgeport V2XT or Hardinge CHNC or Haas VF1 or some such, you probably won't find someone who has already solved the problems, answered the questions, and mapped out the solution.

Instead, a retrofitter looks at the general picture: What are the drives and motors? Have I seen ones like them before? What are the machine accessories and systems? Have I seen similar systems before? Is there documentation available to give me some hints as to how it is supposed to work?

On larger machines, even if you find someone who has retrofitted the same make and model before, it is likely that yours will be different. I have recently been involved in the retrofits of two ca. 1990 Union BFT130 horizontal boring mills. Same make, same model, approximately same year, but completely different headstock configuration, completely different servo drive train, different Y axis brake requirements, different axis clamp requirements, etc..

So, when the more experienced retrofitters here saw your question, they assumed you wanted a more useful answer than "no". But a more useful answer would require more information and more research.

Finally, on subject lines: "Matter of interest" is the type of subject you see on Nigerian scam e-mails. A better pattern might be something like "Has anyone retrofitted a Mazak VQC 20/50?"

[Sudsy55]

I was just interested to know if any one had done one. Wasn't asking for help at this stage but thank you for the insight.

Put that way, I suppose the comparative lack of replies could have been interpreted as "no, no one here has retrofitted an example of that particular machine".

However -- and this should be taken as general advice for the many people who come here with similar questions -- it is not especially likely, and not particular important, that someone else has retrofitted your particular make and model machine before.

There are thousands of different machines out there, and unless you are doing a Bridgeport V2XT or Hardinge CHNC or Haas VF1 or some such, you probably won't find someone who has already solved the problems, answered the questions, and mapped out the solution.

Instead, a retrofitter looks at the general picture: What are the drives and motors? Have I seen ones like them before? What are the machine accessories and systems? Have I seen similar systems before? Is there documentation available to give me some hints as to how it is supposed to work?

On larger machines, even if you find someone who has retrofitted the same make and model before, it is likely that yours will be different. I have recently been involved in the retrofits of two ca. 1990 Union BFT130 horizontal boring mills. Same make, same model, approximately same year, but completely different headstock configuration, completely different servo drive train, different Y axis brake requirements, different axis clamp requirements, etc..

So, when the more experienced retrofitters here saw your question, they assumed you wanted a more useful answer than "no". But a more useful answer would require more information and more research.

Finally, on subject lines: "Matter of interest" is the type of subject you see on Nigerian scam e-mails. A better pattern might be something like "Has anyone retrofitted a Mazak VQC 20/50?"

Ok. Point taken