Servo drive problems

[Jonathan]

Is there a way i can run the servo drives from a breakout board and run the cnc from mach 3 or simlair program?

Plenty of people run LinuxCNC (which is free) with +/-10V analogue signals. You'd probably need to buy a card to enable the computer to output those signals, but it's certainly possible and so long as you do the conversion yourself I expect it would work out cheaper than paying someone to fix it.

Example:
LinuxCNC Support Forum :: Topic: Help please !!! Servo configuration with stepconf. (1/6)

[Tomnewry]

Hi Johnathon thanks for the reply, i intend to do all the work myself do you have a card in mind i was looking at a card called PMDX 126 i think it will run servos what do you think?
Cheers Tom

[m_c]

To go linuxCNC, you'd need something like the Mesa 5I20 ($199) and the 7I33 ($69) daughterboard, plus you'd proably want a 7I37 ($69) to get 24V tolerant inputs/outputs.
The only reason I know about the Mesa stuff is I did consider LinuxCNC, but other than some very basic details about cards that are compatible, I couldn't find any great details about how to set them up or what scripts would be needed to get them to work.

In the end I opted for a Dynomotion Kflop and Kanalog, as the support for both Mach and Kflop is far better.
There are other motion controllers that will work with +/-10V drives. Galil (pretty highend stuff with pricing accordingly), and CS-Lab (relatively new, but their stuff looks good although pricing is top end hobby/lowed end industrial) are two that spring to mind.
To use servos with Mach, you need something to close the loop outside the computer. As has been said, Mach only ouputs step/dir and isn't capable of closing the loop. You either need to close the loop in the drive (most modern servo drives are capable of this), or the motion controller (i.e. Kflop/Galil/CS-Lab CSMIO-A).

The PMDX126 is essentially just a parallel port break out board with a few extra features. It's certainly not capable of closing the loop for servos.

[Tomnewry]

Hi Johnathon thanks for your reply ill have to have a look into this and think about it, cheers for your help.

[Tomnewry]

Hi Johnathon thanks i have been looking at the klop board is that all i would need to do away with the old boards on the computer that are currently being used.
Thanks

[m_c]

I'm going to assume it's me you're asking about the kflop, and not Jonathan?

What exactly you need depends on what other Inputs and Outputs are required.
For my mill, I've got a spreadsheet where I've listed all Inputs/Outputs I'd like, then mapped them to what's avaiable on the Kflop/Kanalog. I know I'll be pushing certain Inputs/Outpus onto MODbus, as the KFlop doesn't have enough Inputs/Outputs.

Before you make any final decisions, I'd recommend making up a list of what Inputs/Outputs you'll need, then seeing what options are suitable. If you want to PM me your email, I'll send you over the spreadsheet I've started for my mill.

I've got the KFlop/Kanalog, but I've had far too many other projects to do, and the cold weather is putting me of spending any more time that required in the workshop! I might get started on the control cabinet next month..