Retrofitting a Fadal with a new controller. Where do you interface new to old ? ?

[CNCAddict99]

Let's say I buy a Fadal machine and I want to replace the controller with something modern. Not sure if this machine will have AC or DC drives. Haven't bought it yet.

Let's just focus on driving the axis motors for now.

Most modern controllers output step and direction signals and either expect the motors/drives to follow that, one way or another. Is there any place in the Fadal control system that would accept step/direction signals from a new controller system ?

I think I read that Fadal motors have either resolvers (DC motors) or encoders ("AC" motors). Is it possible to replace the Fadal motor driver boards with aftermarket drivers like a Gecko, or something similar ?

Another question... Are Fadal DC motors are brushed DC motors ? Are Fadal "AC" motors really brushless DC motors or are they something different ?

Thank you.

[Jim Dawson]

If they are brushed DC motors then Gecko makes a drive that will probably work. If they are AC servo motors then just replace them with modern AC servo motors and drives that will accept step & direction control if that is the controller type you want to use. I'm guessing that the Fadal AC servos are probably analog control, step & direction is not common on industrial class machines because it does not afford the fine control of an analog control. DMM Technology servos are my favorite retrofit servos. https://store.dmm-tech.com/ Trying to make non-matched motors & drives work together is not worth the effort.

If they are DC motors then by definition they are brushed. Most AC servo motors are 3 phase brushless DC motors. A resolver and an encoder perform the same function, they output position data. The resolver outputs a 1V P-P sinewave, the encoder outputs a pulse train, the controller or the drive receives that data and does something useful with it. Either device could be on either type of motor, although I don't recall ever seeing a resolver on a brushed DC motor. Older brushed DC servo systems with velocity drives used tach feedback from the motor for speed control. Newer ones operate in torque mode so do not require tach feedback.

[Mhook]

If they are brushed DC motors then Gecko makes a drive that will probably work. If they are AC servo motors then just replace them with modern AC servo motors and drives that will accept step & direction control if that is the controller type you want to use. I'm guessing that the Fadal AC servos are probably analog control, step & direction is not common on industrial class machines because it does not afford the fine control of an analog control. DMM Technology servos are my favorite retrofit servos. https://store.dmm-tech.com/ Trying to make non-matched motors & drives work together is not worth the effort.

If they are DC motors then by definition they are brushed. Most AC servo motors are 3 phase brushless DC motors. A resolver and an encoder perform the same function, they output position data. The resolver outputs a 1V P-P sinewave, the encoder outputs a pulse train, the controller or the drive receives that data and does something useful with it. Either device could be on either type of motor, although I don't recall ever seeing a resolver on a brushed DC motor. Older brushed DC servo systems with velocity drives used tach feedback from the motor for speed control. Newer ones operate in torque mode so do not require tach feedback.

hi
can i replace dc servo with ac servo on fadal machines without change controller cards??
dc servo has problems a lot

[ianagos]

I would look into the 8k retrofit calmotion offers if you want a modern interface. But otherwise I think the fadal control is great I like it better than the haas control. It’s easier to use with almost all the same capabilities.

I have looked long and hard for a good control and none of them are half as good as the original fadal control.

Linux cnc could be ok but will take a lot of fiddling and will never be as stable as the fadal.

You also make the machine worthless once you remove the good solid electronics.

Think about your decision before you vomit maybe use the fadal control. And if you decide to actually go through with it let me know I’ll buy all the old electronics.

[ianagos]

hi
can i replace dc servo with ac servo on fadal machines without change controller cards??
dc servo has problems a lot

You need new eprom on the cards, new amplifiers, wiring, new amplifier chassis, and probably some other stuff I’m not remembering.

[triumph406]

Running Fadals can be bought so cheaply not sure why you would want to retrofit a Fadal.

But if you were to go down that path a friend of mine retrofitted a Fadal with a Dynamotion controller. He used Chinese AC servos on all axis, the spindle and ATC.

He did it as more of a challenge than something than anything else. He says it's much faster than a DC machine, but at the end of the day it's still a Fadal

[mmurray70]

My 4020 runs off a Dynomotion controller. Using original DC motors and drives, but tachs and resolvers are replaced with high resolution encoders. I really like the dynomotion setup. Its a lot of work to setup but does work really well and its a nice interface.

[mmurray70]

Most of the machine can be controlled by connecting a winford breakout board to the stock Fadal relay board with a ribbon cable. See attached pic. The spindle on and reverse signals go through a different connector on the same relay board. But everything else goes through that ribbon cable. Analog signals for moving each axis go directly to the drives of course.

Fadals are actually really easy machines to retrofit compared to others. The way they setup that relay board is great when doing a retrofit. Still a lot of work though for sure.

[Mhook]

My 4020 runs off a Dynomotion controller. Using original DC motors and drives, but tachs and resolvers are replaced with high resolution encoders. I really like the dynomotion setup. Its a lot of work to setup but does work really well and its a nice interface.

what type of high resolution encoders !?

[mmurray70]

Im using these encoders: https://www.ebay.com/itm/Teledyne-Gu...-/133163839001

These connect directly to the Dynomotion boards and they handle everything, no feedback to drives at all. Drives have been modified to operate in torque mode. The Analog signal bypasses all the tuning pots on the drive, and all tuning is handled by the Dynomotion system.

No Tach or resolver problems to worry about anymore.