Choosing Mesa Hardware?

I am trying to decide what Mesa Hardware to choose.

I have an 8 motor gang router that is used for wood engraving.
It is ran by step/dir servos, and is currently software stepping.
I would like to switch to hardware stepping and I'm trying to decide what hadware to get.
I think it might be advantagious to add encoder feedback, partly to aid in tuning the drives, and possibly running velocity mode insted of just positioning. Is this worth the added expence and effort?
I also want to add control of the spindles. Right now there is no connection between the VFDs and LinuxCNC. At minimum I want to add start/stop and fault signals, but I might also like to be able to set the speed if it isn't to hard.

If I didn't want to set the spindle speed, which is going to need an analog signal, I was thinging a 5i25+7I85S+7i84 might work nicely.

If I didn't want to do the encoder feed back then a 5i25+7i76 is an easy choise.

But if I want both the speed control and encoder feed back, am I best getting both the 7i76 and the 7i85?

I am also concerned about connecting to the TTL signals for enable and fault signals on the servo drives, thinking that I might need to keep the 2nd port on the 5i25 free to use for that stuff. I suppose If I had to, I could use the LPT port for that.

Any suggestions, or better ideas?

If you use a 7I85S and the router is 3 axis, you have a free step/dir
pair which could drive a analog spindle interface
(say our SPINX1)

Thanks,

That sounds perfect, I didn't see the SPINX1 on your price list.
How much does it cost?

I think its $24.00

Todd wrote:

I am trying to decide what Mesa Hardware to choose.

I have an 8 motor gang router that is used for wood engraving.
It is ran by step/dir servos, and is currently software stepping.
I would like to switch to hardware stepping and I'm trying to decide what hadware to get.

You might also want to look at the Pico Systems Universal Stepper Controller
(see <pico-systems.com/osc2.5/catalog/index.php?cPath=4>
for more info). This will drive up to 4 stepper axes at up to 300K steps/second,
with much smoother trains of step pulses than software stepping. It also
can use encoder feedback, and essentially always runs in velocity mode.
An optional spindle DAC can produce 0-10 V spindle speed command.
When you add all the optional mezzanine boards to the Mesa product,
the price difference pretty much disappears.

Jon

I think the Mesa is still a little bit cheaper, and I need more io than your Universal Stepper Controller

At this point I am counting 26 inputs and 12 out not counting the step/dirs, encoders and, the analog spindle signal.

When I ran the hardware purchase by our IT guy, he asked "Why not use Modbus to control the 8 VFDs?" I didn't have a good answer other than "I don't know how to set them up with Modbus."

From the surface it certainly looks simpler from a hardware standpoint. But, how practical is it to control 8 VFDs (they are Lence AC Tech SF230Y) with LinuxCNC through Modbus? What would be the best way to do that, Classic Ladder?

Problem is I don't know the first thing about Classic Ladder or PLC setup. I know, I know, it’s a good excuse to learn it. But that looks like a pretty steep hill from down here.

Can anyone point me towards some good tutorials?

Modbus is simpler hardware wise (especially if the drives support Modbus TCP)
but may require some software fussing about

If you have not seen this, it's at least an introduction:

wiki.linuxcnc.org/cgi-bin/wiki.pl?VFD_Modbus