Secondary High-Speed Spindle

I will be adding a high-speed spindle to my mill in near future and would like to have some ideas how to.
Primary use will be PCB milling/drilling

Spindle is a Spintec VM 17 R with max rpm of 54.000 at 900Hz and 189VAC 400W output
VFD to be used is Omron MX2-AB004-E single phase to 3-phase 400W

Want to connect this to my 7i76e, primary spindle is using normal spindle output.
This VFD has Modbus and analog 0-10V so my question is how to build up a separate HAL file
and what method to control the spindle, assuming a set of M-codes will be needed for this spindle.

GUI is Gmoccapy.

Hints and pointers please

Will both spindles be mounted to the machine at the same time or will you have to physically swap spindles to use one vs the other?

If both are mounted and you need to easily switch between one and the other, I think you have several options:
1) You could have separate configs for each spindle, but this requires you shut down Linuxcnc to change. (this is probably the better option if you have to physically mount/unmount a spindle.)
2) You can set up some M codes to control how and to which drive the spindle commands are sent to.
a) You could use the single analog out hardware on the 7i76e and control which VFD gets the signal with a relay or two.
(This might be a little tricky as the drives might not like having a common voltage reference.)
b) You could control one or both the drives using Modbus

I have controled multiple spindle drives on cnc routers with Modbus and without it. But the machines I have that don't use Modbus, don't have any speed reference signal, they are only on/off.
I have custom M-codes setup that enable or disable the VFDs that I want to run and control where the spindle commands are sent. I can select which drives are on or off or if I want multiple drives on. I also have on screen indication of what drives are enabled/disabled.

Hi Todd,
Primary spindle is fixed and will always be there that is analog out is occupied.
Secondary will be only mounted when need be. No speed feedback, approx spindle speed via Modbus or 0-10V.

I do not know so much about Modbus but I assume all needed can be controlled that way.

Cheers
Bengt

Yes, you can control every thing that is needed from Modbus, plus get additional feedback from the VFD that wouldn't normally be accessible.

The big problem with Modbus is that it only defines the communication there is no standard about how or what is sent, so every drive model needs a different Modbus driver. Even different models from the same manufacturer may not be compatible. There is fortunately a very basic generic Modbus driver included with Linuxcnc, configuring it is a laborious affair with a steep learning curve and you will need the Modbus documentation for your drive to figure it out. (It is about as involved as setting up an entire Linuxcnc config.)

The documentation Linuxcnc's generic Modbus driver "Mb2hal" is also a bit lacking. It pretty much just consists of a heavily commented example configuration file. Read up, ask questions. It has been a number of years since I set up a Mb2hal config. But we will do our best to answer your questions.

At my first glance this whole Modbus looks intimidating for me.

Is there any other way to generate 0-10V from 7i76e / 7i85S as the primary spindle is occupying analog out.

You could probably setup one of the stepgen outputs that you don't need as a pwm output and run that though something like a Mesa Spinx1 to get another analog output.
store.mesanet.com/index.php?route=produc...oduct&product_id=205
I think that will need a different firmware config for your Mesa cards.

Setting up Modbus control was intimidating for me as well when i set it up. But I had little choice, because I needed to control 8 VFDs on a gang router and had to make it work. (I didn't think it would work to send 1 analog signal to 8 drives.)

Thanks Todd, will ask Peter to see if that can be possible to use Spinx1.