(NEWBIE) How to use an (Fanuc) AC Spindle servo motor for an DIY CNC router

I have a Fanuc spindle on my older mill (stock Fanuc control, not LinuxCNC). It can orient for tool changes or broaching. I don't think you will be able to orient with a VFD drive.
Mine can tap with a tension-compression holder, but will not rigid tap.

If you want to use a ATC with a VFD spindle you may be able to do like some HAAS machines and use a lock pin to orient the spindle. It turns slowly until the pin drops into a slot.

LinuxCNC does support rigid-tapping with a VFD-controlled AC motor. It does this by slaving the Z-axis to the spindle encoder, rather than by trying to accurately control the spindle position.

It is also entirely possible to align a spindle with a conventional motor and VFD, quite a few LinuxCNC machines do exactly that.

Sorry if I was misleading. I'm a newbie too.

Thanks, especially to andypugh.
@"If the currently-fitted encoder works then there is probably a way to interface it with LinuxCNC."
Really, could that work ? I ask, because here in this thread on SITE 1 / Last post, the user PCW wrote: "Note that the encoder has no commutation pins". Maybe i do understand it completly wrong, but how can i then connect it to the VFD. For example, VFD Vector drives like YASKAWA A1000 needs an incremental encoder.

There are still some questions i have where i could really need some help.

1. VFD (very important):
The motor needs an of 3phase 200V INPUT, but my suppy in my workshop has 3phase 380-400v. When i look at the parameters of VFDs (vectro drive) there are always 2-3 volt versions:
version 1: INPUT: 380-400v, OUTPUT: 380-400v
version 2: INPUT: 200-240v, OUTPUT: 200-240v
*version 3: 690v...., but thats of course not the right one for me
On some pages there is this kind of info for 380V-400V:
INPUT ~ 380..480V +-10%/-15%, 50/60 Hz +-5%
OUTPUT: 3 ~ 0 - 380..480V
So, when there reads "OUTPUT: 0 - 380..480V", does that mean i can choose the voltage from 0-480V ? Or do i need an step-down transfomer (from 380v-400v to 200v-240v) between my 3phase 380V and the VFD (version 2. 200V-240V input and output) ?

2. Boards, cards, etc. (very important)
Could you tell me which cards, boards, etc. i need to use the VFD with the AC spindle motor and do all those things like rigid tapping and using an ATC ? Of course i tryed to find the information by my own, but im just not sure: Do i just need MESA 7i77 + 5i25 Plug and Go kit and an Motion board?(+ PC and linuxCNC) ? Where do i know which is the right motion board - is it depending on if i use hybrid closed loop steppers or servo motors for my XYZ Axis ?

3. Used industrial servo motor for axis :
When buying used servo motors (for axis) without the original drives, which "new" servo drives can i then use for the servo motors ? I saw many poeple retrofiting there mills and lathe with new drives, but keeping the old servo motors.

4. ATC (not that important, because its something i want to "maybe" use in future - want to have that option open):
I have read that its necessary to always zeroing the Z-axes to use an ATC, is that true ? The questions might be a bit too generally, but thats because i dont understand it very.
4.1 ATC: Is it difficult for an newbie to do the settings to use an ATC ? Is there any tutorial, or some easy way to set it up?

5. Rigid tapping (not that important, but would like to know for future) :
Is it difficult to set it up on LinuxCNC ? Do i need some extra card, board or anything?


Thats all. Hope you can help me out with that.

BR,
Denis

denhen89 wrote: @"If the currently-fitted encoder works then there is probably a way to interface it with LinuxCNC."
Really, could that work ? I ask, because here in this thread on SITE 1 / Last post, the user PCW wrote: "Note that the encoder has no commutation pins". Maybe i do understand it completly wrong, but how can i then connect it to the VFD. For example, VFD Vector drives like YASKAWA A1000 needs an incremental encoder.

An induction motor does not need commutation signals.
Some VFDs need an encoder, some don't. Sensorless ones are easier (and cheaper) to deal with.
LinuxCNC does need an encoder for tapping and spindle-orient.
The encoder actually needs to be on the spindle, not on the motor, unless the drive is exactly 1:1and using a toothed belt.

So, when there reads "OUTPUT: 0 - 380..480V", does that mean i can choose the voltage from 0-480V ? Or do i need an step-down transfomer (from 380v-400v to 200v-240v) between my 3phase 380V and the VFD (version 2. 200V-240V input and output) ?

This has never been my problem, but I think that you can do this with the V/F curve
www.vfds.org/variable-frequency-drive-li...teristic-923331.html

Could you tell me which cards, boards, etc. i need to use the VFD with the AC spindle motor and do all those things like rigid tapping and using an ATC ?

This depends on the VFD, but in many cases you can do this with a $2 USB to Modbus dongle. For better real-time performance, though, something outputting analogue voltage and direction is likely to work better. Many simple (and complex) break-put boards have this feature built-in.

Where do i know which is the right motion board - is it depending on if i use hybrid closed loop steppers or servo motors for my XYZ Axis ?

Yes, the interface board you need will depend on the other components of the system.

When buying used servo motors (for axis) without the original drives, which "new" servo drives can i then use for the servo motors ? I saw many poeple retrofiting there mills and lathe with new drives, but keeping the old servo motors.

This depends on the servo motors, and on whether they are DC or brushless, and in the latter case what commutation signals they have.
Some motors really won't work without their matched drives. You need to do research on specific models as they pop up on eBay.
Some time ago I made the mistake of buying some nice servo motors which had resolvers for feedback and commutation. I ended up writing a driver for the Mesa resolver interface card. (Which is now included in LinuxCNC, and, actually, resolvers are more standard than some of the proprietary serial-quadrature encoders)

ATC (not that important, because its something i want to "maybe" use in future - want to have that option open):
I have read that its necessary to always zeroing the Z-axes to use an ATC, is that true ? The questions might be a bit too generally, but thats because i dont understand it very.

You will need to home the Z axis anyway to have any hope of making repeatable parts. It's just part of the machine turn-on process.

4.1 ATC: Is it difficult for an newbie to do the settings to use an ATC ? Is there any tutorial, or some easy way to set it up?

Sorry to be unhelpful, but it very much depends on the ATC. Some are easier than others.

5. Rigid tapping (not that important, but would like to know for future) :
Is it difficult to set it up on LinuxCNC

If you have a spindle encoder and LinuxCNC can reverse the spindle motor, then that's all you need.