Possibility of a Retrofit on Alcor 220CNC

Greetings everybody,

I´m Matthias from Germany and have recently bought a used CNC-Mill with a defective Heidenhain iTNC530 control. After a long call with the really supportive folks at Heidenhain there are a few easy tests left for me to run, but everything seems to point to a fault in the control's hard drive. In that case I would not only need a new hard drive but also the parameter list from the manufacturer.

However I am not enclined to spend much time and money on this "old"(2005) controller and have another fault in half a years time. If the control ran fine i would be more than happy to use it.

At first glance into the control cabinet the electronics are all in good order and working condition. The big drives for the servos and spindle appear to be functional and it does not look like someone tried tinkering with the machine before. As I understand it, this machine was sold new to a company which then used it until it faulted out and some time after the company went bankrupt and sold the shop with the machine. Now the new owner of the shop has no interest in this non running machine which is why i got it for a good price considering the mechanical state of everything.

I had thought about the possibility of a retrofit with linuxCNC from the moment i knew this machine had a faulty control.
These are a few key points i had in mind:
-Reuse of all motors and drivers (3 axes, 1 spindle, speed control only with vfd, no gearbox)
-Reuse of the Heidenhain monitor and keyboard (if that is feasable and someone knows how to do it)
-Control of other systems like lubrication and hydraulic pump should be no issue as I see it

As this would be my first retrofit and I have no experience with linux or linuxcnc a lot of hand holding will be required. However I am willing to invest a lot of time and effort into this machine. I hope i can get away with buying only a computer and the Mesa cards, but not any servo drives or other high load components.

I hope I can find a lot of helpful and exerienced people here and make a good job of this retrofit.

Best regards

Most important question is what motor drives does the machine use (ie for axis motors and for the spindle). If the current drives accept either analog or step/dir signal then they are usually fine for a refit. If they use some kind of serial interface then things get difficult.

The drives use an analog signal from the control. I was also able to find datasheets and the software to tune these drives online.

Yes, the signal is +-10V

In terms of number of IO pins, the control currently has 18 digital outputs, 34 digital inputs, the 3 analog axes, an analog signal (also +- 10v)for the vfd and two more analog pins.
The machine has position feedback through Heidenhain glass scales and a 3 axis module with a single output cable. To close the position loop, the data from this 3 axis module must also be read into linuxCNC, right?

@tommylight: are you referring to the mesa cards i would need to run this system?

Also, the machine comes equipped with 3 encoder handwheels on the front of the machine. I think that layout is really slick for manual type work on this machine and general movement compared to pressing buttons at the control. I've read before that with linuxCNC anything is possible if you are willing to tinker with the software and invest enough time, so adding these 3 "Jogwheels" should not be a problem right?

I'm thankful for any input of the many knowledgeable people here. I am currently educating myself on the topic of mesa cards and interfaces. So far I have the feeling that this retrofit will work well given that all 24v relais and the axis/spindle drivers can be used.

Are there any well documented "by the book" retrofits that I can study to see how this is done properly.

Yes I'm pretty much set on the retrofit since I just heard from Alcor's supplier that the parameter list is not available anymore.

I have always found a good search through the linuxcnc manuals to be of great benefit. See link
linuxcnc.org/docs/stable/pdf/

I would note that it would likely be easier
to find a 7I97T than a 7I97.

Mesa Cards have seperte MPG inputs (5 v signal) Often  only 2 but I'm sure different firmware can add a third at the expense of some inputds
Ref: linuxcnc.org/docs/stable/html/examples/mpg.html
(Example is Single MPG  with multiple axis select but easy to make it for a single axis.)