97 fadal dc motors with Glentek amps

[rangerboy347]

I'm thinking about doing a swap looking for best options.

Option 1 Allin1DC? but my motors are 75in-lbs/20 current. this is higher then the Allin1DC says it can drive am I correct? If I am able to use for my current motors are there schematics for connecting to my drives?

Option2 oak and swap all motors to AC. I'm trying to find out the frame size I think its Nema56c or maybe 60 frame size. so I'm not sure how expensive servo and drives of this size will be.

One last question does anyone know if I can just connect a servo drive to the fadal control? like instead of using the Glentek drive just connect a Ac servo drive? so lets say I have a DMM or similar drive?

[martyscncgarage]

I'm thinking about doing a swap looking for best options.

Option 1 Allin1DC? but my motors are 75in-lbs/20 current. this is higher then the Allin1DC says it can drive am I correct? If I am able to use for my current motors are there schematics for connecting to my drives?

Option2 oak and swap all motors to AC. I'm trying to find out the frame size I think its Nema56c so I'm not sure how expensive servo and drives of this size will be.

One last question does anyone know if I can just connect a servo drive to the fadal control? like instead of using the Glentek drive just connect a Ac servo drive? so lets say I have a DMM or similar drive?

Have you contacted Glentek for a manual? FADAL usually had drives that were custom made.
Oak may be able to do it. I don't have personal experience. Perhaps CNCSNW will chime in.

What is your expected budget to do the conversion, and do you have the skillset to carry it out to the end?

Yes, AC servos and drives would be best, but it depends on your budget.

Marty

[rangerboy347]

I have found the manuals for the drives. I have already done two acorn conversions one lathe and a mill. I'm not sure on budget would say 10K or less considering I payed 2500 for the fadal with Renishaw probe and 4th axis. I just like the centroid user interface much better and it can probe much easier. Would be simple if i could just use the signal if put out to drive my own servo drives but I doubt its that easy lol
joe

[martyscncgarage]

I have found the manuals for the drives. I have already done two acorn conversions one lathe and a mill. I'm not sure on budget would say 10K or less considering I payed 2500 for the fadal with Renishaw probe and 4th axis. I just like the centroid user interface much better and it can probe much easier. Would be simple if i could just use the signal if put out to drive my own servo drives but I doubt its that easy lol
joe

Do you have the drive manual in electronic format you can post?

[rangerboy347]

glentek manual as close as i can find

[Centroid_Liviu]

On page 15 of the Manual (Page 22 of the PDF) it lists -10 to to +10v for Velocity mode command input. So the Oak should be able to command it. The issue you will run in is that the drives still expect a tach signal in order to function, but the Oak is fully closed loop and will need differential quadrature encoders. Encoders would need to be installed on top of the tachs. So you could theoretically get everything working this way, it would not be the simplest solution however.

[martyscncgarage]

On page 15 of the Manual (Page 22 of the PDF) it lists -10 to to +10v for Velocity mode command input. So the Oak should be able to command it. The issue you will run in is that the drives still expect a tach signal in order to function, but the Oak is fully closed loop and will need differential quadrature encoders. Encoders would need to be installed on top of the tachs. So you could theoretically get everything working this way, it would not be the simplest solution however.

Thanks Liviu for chiming in. This is what I thought.
Hopefully Marc Leonard (CNCSNW) Can chime in on the complexities of doing the conversion this way.
I might be tempted to go this route, PROVIDED the DC Brush Servos are still in good condition.
If they fail and you should so choose, you could swap out the drive and motors with AC Servos compatible with OAK at a later time.
You do however need to pull the end caps off your motors to make sure there is a stub and room for an encoder. You can always make a cap extension, but you need the stub on the end of the servo motor shaft to attach the encoder.

Marty

[cncsnw]

There are probably encoders already, wired to the Fadal control. Else how would the CNC know the axis positions?

While the Oak will output a +/-10V analog velocity command, it also has some fairly specific requirements for the enable and drive-fault interface, which are likely not plug-and-play with the Glentek drives.

For example, Oak expects a drive-fault (or rather, drive-ok) signal that sinks 24VDC to 0VDC (logic ground) when all is well.

You might find the MPU11+GPIO4D combination a little more versatile. In either case you will probably need relays in between the Centroid board (Oak or GPIO4D) to invert the enable signal.

Both Oak and GPIO4D expect to be able to enable the drive by pulling an enable signal down to 0VDC / Logic Ground. I do not have time to review your manual right now, but most Glentek and AMC amplifiers I have seen are enabled by default, and instead have an "inhibit" input. The last set of such drives I worked with required +5VDC applied to the inhibit input when *not* enabled, and an open circuit when the drive is to be enabled. This required an intermediate relay.

Oak does not supply 5VDC to its axis encoder inputs, since it assumes that encoder circuits are powered by the servo amplifier. You will likely need to supply 5VDC directly to the axis encoders, since they probably are not routed through the amplifiers. If you use an MPU11 and GPIO4D, then you would connect the encoders to the 9-pin receptacles on the MPU11 board, which does provide 5VDC.

[rangerboy347]

For some reason i was thinking that the Oak board only did AC servos. The dc servo motors in machine have resolvers and motor tachs. there should be plenty of room to change the resolver to an encoder from the motor i have had end cap off. Next thing if i would need to replace the current servos what size will I need? What frame are the motors centroid stocks? From what i have found so far they are calling these 56c size. On my other builds i didn't have a tool changer to deal with how hard will the PLC be for this also?

joe

[cncsnw]

You could replace those motors with 1.3W Yaskawa motors (e.g. SGM7G-13A..., with SGD7S-120A... drives). That would provide a maximum continuous torque of 74 in-lb, and an instantaneous peak torque of 207 in-lb.

You would need to modify the motor mounts, and modify or replace the pulleys or couplers.