Which Mesa board?

Hi All, A few years ago I built a 4 axis mill, converted a Chinese drill mill. It works surprisingly well. I went from Mach 3 to Mach 4. Im not overly satisfied with the performance and feel it could be a better.
I want to switch the whole show over to Linuxcnc.

XYZ are brushed DC servos coupled to step and direction drives with encoder feedback. The 4th axis uses a Leadshine drive with hybrid stepper again with encoder feedback.

The set up uses mach 4 with Ethernet smooth stepper connected to a classic breakout board. My early research suggests I can switch to Linux cnc and replace the Ethernet smooth stepper with a Ethernet Mesa board which would connect to my existing breakout board via a ribbon cable.

Am I on track? If yes can any one can suggest a Mesa board that will do the trick, perhaps the MESA 7i92M

Paul

It might be a bit more work to migrate to Linuxcnc from your BOB this way but its hard to go past the Mesa 7i76e ethernet card. 5 step generators, spindle interface with encoder input, 2 MPG inputs, 16 outputs and 32 inputs and a few other features. Plus almost unlimited expandability.

I've not used one, but I think the 7i92 will let you use an existing BOB, but the 7i76e is vastly superior. You just need about a 2 amp 24 volt power supply, and maybe some 24 V relays.

The 7i76eD is designed for active low switching which might suit your existing wiring and sensors better.

Thanks Rod,

Im new to linux CNC. But Im sold on it.
I have also have a Kasuga mill with Heidenhain 355 control to retro fit next so cutting my teeth on this small drill mill first as all the hardware is done and working.

I was expecting the PC via Ethernet would couple to the economic 7i92M and then the 7i92M on to the existing BOB via the 25 pin interface, I think that would work. The MPG may be an issue. (Currently don't have one)

So yes I started looking at the 7i76E which looks even better I like the idea of connecting the MPG directly the the 7i76E. The existing BOB would stay in play save me on rewiring.

There is also the option of getting the 7i92 and later on getting a 7i76.

I think if I was going to keep the BOB, I'd save my money and go with the 7i92.

But you do leave a fair bit on the table that way I think. I've never used Mach or BOB. I have a mate who lives a few doors down who knows Mach backwards which would have been handy if I chose Mach when I started but everything I saw said Linuxcnc was superior in every respect.

One of the positives I saw was that the Mesa cards would allow a more robust industrial 24 volt logic system that was significantly more impervious to noise than lower voltage systems. It needs a lot of noise to invert a signal at 24V!

The other alternative would be to spend nothing, turf the smooth stepper and spin up your BOB via a parallel port.

Rod, yes I'll order the board soon. One last question, if I go with the 7i92 is a wired MPG going to give me much grief to set up?