[birdman3131]

Ok we have an old plasma cutter that has fubared motor drives. (I think the motors them selves are ok but I dunno if they are worth keeping.)

Do I need steppers or servos?
How do I figure out how powerful they need to be?
What controller? The current one is an old PMAC ISA board that is somewhat old and I doubt we could get much documentation for

I don't really need Z although I guess it would not hurt. But the torchmate system has a couple inches of z control if needed.

I can't really get much good info off the current motors. The nameplates are nigh unreadable.

Here are some video and photos.
https://imgur.com/a/tUP37
https://www.youtube.com/watch?v=QzlJhOb3LuY
https://www.youtube.com/watch?v=3uvcyln1zwg

[greggv]

PMAC is from DeltaTau and is very good equipment. I'd definitely keep that. They sell motor drives along with a host of other companies. The PMAC is going to output =/- 10 vdc. Some of them can do step and direction, but I'd imagine you'll want analogue.

[Al_The_Man]

I have done a couple of gantry Oxy/gas cutting machines about that size using a similar motion card by Galil, If there is info as to Ft-Pl's on the motor plate and as mentioned, the drives are typically ±10vdc analogue and if drives are needed yu could look at A-M-C or Copley Controls etc.
Al.

[birdman3131]

Last time we talked to delta tau they had no clue that you could even use gcode with this board which we had been doing since before I came here. They had no one still employed that had messed with it from what I understood (And this was back in 2010 or so.). I am not opposed to using it but I would like to get away from windows 95/98 as well.

The board is a pmac-lite 56002 which does not seem to have a manual on deltatau's site although the lite 1.5 may be close.

[Al_The_Man]

Last time we talked to delta tau they had no clue that you could even use gcode with this board which we had been doing since before I came here. .

The board is a pmac-lite 56002 which does not seem to have a manual on deltatau's site although the lite 1.5 may be close.

Maybe not with that board, but I have seen Delta Tau machine running CNC at the IMTS show quite a few decades ago.
The Booth was Delta Tau.
Al.

[mike_Kilroy]

Sounds like you absolutely want to replace that great delta tau control so just do it.

Since you consider steppers you might as well remove those dang good mavolor motors to.

Do you have any idea the hi performance required for plasma cutting?

Thanks for the good laugh about no one left at DT with a clue or manuals not being available for the motors or DT!

Bet that "POS" control was made by a great company called Hypertherm and bet you know they too are out of business?

Sent from my SM-G900V using Tapatalk

[Jim Dawson]

I have worked with Delta-Tau controls. They won't run G-code directly unless they have some very special firmware installed. You need some software to translate G-code into something the Delta-Tau understands, that's what your user interface does. Just like Galil controllers, and others.

If the drives are dead, which I would find it odd that they all died at the same time, then replacing motors and drives would be my choice. Kind of hard to tell from your videos, but that looks like a pretty beefy machine. I would concider ClearPath SKHD or DMM servos. If you want to keep the Delta-Tau controller then the DMM servos would be the best choice because they take an analog input. If you want to change out the whole control system then either would work.

You have a number of options available if you want to change out the whole control system.

[birdman3131]

I have worked with Delta-Tau controls. They won't run G-code directly unless they have some very special firmware installed. You need some software to translate G-code into something the Delta-Tau understands, that's what your user interface does. Just like Galil controllers, and others.

If the drives are dead, which I would find it odd that they all died at the same time, then replacing motors and drives would be my choice. Kind of hard to tell from your videos, but that looks like a pretty beefy machine. I would concider ClearPath SKHD or DMM servos. If you want to keep the Delta-Tau controller then the DMM servos would be the best choice because they take an analog input. If you want to change out the whole control system then either would work.

You have a number of options available if you want to change out the whole control system.

Well the current system is a very homegrown black box by somebody else with no documentation and wired up using bread boards. Which was ok while it worked but then it started acting up (At one point a water pipe busted and got everything wet.) it worked for a while later once we bought another win 98 computer but it now has an issue where one of the axis will work for about 20-30 seconds and then just die. Swap drives and it follows to the new axis. We bought another drive but had issues with it as well.

I also know that there is major electrical noise in the system as well as soon as I turn on the drives from when I hooked an Oscope up to it when troubleshooting it a while back. I would like to start fresh so as to hopefully get rid of this as well. (The noise has nothing to due with the plasma system because that is still off at this time.)

Mechanically it is sound but electrically it is probably better to start over from scratch. If the pmac board is a good board then I am ok with keeping it but I had assumed there were better options than an old ISA board. The drives definitely have to go and I have had no luck figuring out what drives are compatible with the servo motors so they may have to go as well.

I may look and see what we have laying around but most of our junk machines are old 70's era Matsura's and those old drives are "fun"

And yes the machine is beefy. It used to be a water cutter with Allen Bradly controls before those died and the current setup was done.

[Jim Dawson]

I think I would lose the ISA board. And after the bath, everything is suspect especially around a plasma torch. The fact that you know how to use a scope means that this is going to be an easy project for you. Then it just a matter of budget.

The inexpensive way to go is Mach3 or Centroid Acorn and ClearPath servos. Both are open loop systems, but the ClearPath servos close the loop at the drive. If you are wanting a full closed loop system, then the higher end Centroid systems would work. Also look at the DMM servos they will take step & direction or analog input, increases your control options. The DMM servos can also close the loop at the drive in step & direction mode.

[birdman3131]

Sounds like you absolutely want to replace that great delta tau control so just do it.

Since you consider steppers you might as well remove those dang good mavolor motors to.

Do you have any idea the hi performance required for plasma cutting?

Thanks for the good laugh about no one left at DT with a clue or manuals not being available for the motors or DT!

Bet that "POS" control was made by a great company called Hypertherm and bet you know they too are out of business?

Sent from my SM-G900V using Tapatalk

I probably shouldn't reply but Ill try to address some of these.

Slightly considered steppers. Did not really think they were great but put them out as an option. I have never used them other than on a 3d printer and that came with them built in so it does not really count.

The Mavlolor motors are probably still good but the drives are toast. I could try replacing just the drives but seeing as I can't get info off the faceplates as to the specs of the motor I cant really get matching drives.

As for plasma cutting being high performance Im not sure what you are referring to there. If you are referring to accuracy it is not all that great. We have better equipment for accuracy. (Mills and EDM in house and a laser cutter in town we contract to occasionally.) This is only for rough work.
If you are referring to speed that could be an issue and I will freely admit I don't know how to calculate what size motors I need to move the machine at a given speed. That is part of why I came here to ask. (Normally I would try to match the current motors but again the faceplates are faded.)

As for Delta Tau I have no real issues with them. I just want to get away from the requirement for an ISA slot which was removed from essentially all computers 15+ years ago. I deal with enough other computers and electronics from the 70's/80's that the fewer the better.

As for them not being knowledgeable in general I was not trying to say that just that when we talked to them 6-8 years ago we were told that everyone who had first hand knowledge of our board was retired. That may not have been true but it was what we were told. I do know that we confused them when we told them we were importing gcode into their software. Apparently the newer boards and/or software did not support that.

As for the control. The machine was a water cutter with allen bradly controls. These died long before I came here and was replaced by the pmac board and this lovely mess. Pretty much all the original controls are bypassed including the ability to home. (I think the limit switches may be out of the picture as well but I am not sure. Either way I plan on hooking them back up. At some point it was also converted from a water cutter to a plasma cutter. I do not know if this was done at the same time or not.

[birdman3131]

I think I would lose the ISA board. And after the bath, everything is suspect especially around a plasma torch. The fact that you know how to use a scope means that this is going to be an easy project for you. Then it just a matter of budget.

The inexpensive way to go is Mach3 or Centroid Acorn and ClearPath servos. Both are open loop systems, but the ClearPath servos close the loop at the drive. If you are wanting a full closed loop system, then the higher end Centroid systems would work. Also look at the DMM servos they will take step & direction or analog input, increases your control options. The DMM servos can also close the loop at the drive in step & direction mode.

I am liking the look of the clearpath servos. Just gotta make sure that they have enough power. I think they should so long as I don't try to go too fast. But Not entirely sure

[mike_Kilroy]

You should not guess at motor and drive sizes. Use one of the free motor sizing programs and enter what you know to let them pick the proper size motors and drives for you. Use any one of the free ones like this. ONce it tells you the torque, speed, inertia you need, then you can go shop elsewhere if you are so inclined. Just don't guess.

https://www.kollmorgen.com/en-us/ser...eering-online/

[Jim Dawson]

Like Mike said, make sure that the motors you buy have enough torque. If you can find the specs on your existing motors, that is the best guideline, then where possible I normally go with one at least one size bigger. You can always turn down the power, but it's pretty hard to squeeze any more power out of an undersized motor.

I just went from 12N/m stall to 29N/m stall axis motors for my lathe. I'll start by limiting the torque to about 50%

[mike_Kilroy]

The Mavlolor motors are probably still good but the drives are toast. I could try replacing just the drives but seeing as I can't get info off the faceplates as to the specs of the motor I cant really get matching drives.

But but but... your first video showed a Mavilor nameplate for like 0.5 sec and it seemed perfectly readable?

[birdman3131]

But but but... your first video showed a Mavilor nameplate for like 0.5 sec and it seemed perfectly readable?

The same nameplate is in the imgur album I linked just above the video. https://imgur.com/a/tUP37 The nameplate was laser etched and the etching is mostly faded however I went out this afternoon and uninstalled the motor and got it in some brighter light.

I still can't read the model number but I think I got enough of the others to make out enough.

Ncm =355 (502 oz-in)
V=100*
Amp=13*
RPM =3000

*Not as sure on these but that was the best I could read

The clear path servos look to have some that exceed the Ncm assuming that is equivalent to the continuous torque listed on their specs. The RPM is lower at 2500 RPM but there is no way I would ever use a fraction of that.

Tomorrow I will try and remove the Y motor and see if it matches the X motor I pulled today. I would not be surprised to see it larger seeing as it moves the entire gantry.

[birdman3131]

Just got the torque off the other motor and it is more. 685 Ncm (975 oz-in) Still within the realm of the clearpath motors.

[Jim Dawson]

Sounds like you are good to go, now it's just a matter of choosing a control system.

[Al_The_Man]

Out of interest this is the main travel axis I installed on an old trace cutting machine conversion to CNC using a Acroloop Motion card .
I used Bayfield planetary gear boxes to make the drive and motor size more economical.
The gantry must have weighed 300lb plus.
Al.

[birdman3131]

Sounds like you are good to go, now it's just a matter of choosing a control system.

Yah. For now I am gonna get the motors in and hooked up before I figure out what control/software I am gonna use. And then wiring up the limit switches and figuring out how to interface the torchmate that keeps the height adjusted. (It was not hooked to the pmac board but IIRC it was supposed to be possible to wire it to the controller for some extra features.)

Thanks to all of you for the wonderful help.

[Al_The_Man]

It is a pity that the Acroloop card was sold to Parker, when they originated in Chanahassen MN they had a nice CNC motion card product, together with their engineer developed CNC S/W.
I lost track of them once they were sold, I believe they still are produced by Parker-Hannafin but no idea what the price is now.
I actually liked it a little more than Galil at the time as they had a couple of PLC's on the card for handling the M codes etc.
They were actually used by a couple of large Plasma companies at the time.
Al.