CNC Colchester chipmaster

[Clive S]

I use the mesa 5i25 + 7i76 which from the manual gives:-


The 7I76 is daughtercard/breakout board for use with MESA's 25 pin I/O FPGA
cards like the 5I25. The 7I76 is designed for interfacing up to 5 Axis of step &dir step
motor or servo motor drives and also provides a spindle encoder interface, isolated analog
spindle speed control and 48 isolated I/O points for general purpose field I/O use.
All step and direction outputs are buffered 5V signals that can drive 24 mA. All
outputs support differential mode to reduce susceptibility to noise. An isolated analog
spindle voltage with direction and enable outputs is provided for spindle control as is a
single spindle encoder channel with TTL or differential inputs.

48 points of isolated field I/O are provided for general control use including limit
switch and control panel inputs, coolant enable and tool changer control outputs. Isolated
I/O includes 32 sinking inputs and 16 sourcing outputs. Inputs can sense 5V to 32V signals
and the outputs can switch 5V through 32V signals. Maximum output load is 300 mA.

Outputs are short circuit protected. Field I/O is powered by an isolated 8-32V field power
source.

The 7I76 provides a one channel encoder interface with index. This is intended as a spindle encoder but can be used for other purposes. The encoder input can be programmed for differential or single ended encoders. The encoder interface also provides short circuit protected 5V power to the encoder. When used with single ended encoders, the ENCA+, ENCB+ and IDX+ signals are wired to the encoder and the ENCA-,ENCB-, and IDX- terminal left unconnected.

Mesa cards can be purchased in Europe.

[Ross77]

Do you use Pathpilot with that? how difficult was it implement the spindle encoder?

[Clive S]

Do you use Pathpilot with that? how difficult was it implement the spindle encoder?

No I don't use PathPilot but do use the spindle encoder for the lathe and that is very easy to setup I have also setup jog wheels for X and Z on the lathe.

There is a tutorial on the other channel by cncbasher to set up PP. https://forum.linuxcnc.org/forum/pat...tutorial-part1

I used the same control box for the Mill and the Lathe and just use two different profiles.

[Ross77]

Hi Clive
Could you elaborate on using PP without a mesa card? all the posts I read say that PP wont install without a mesa card.

Do you not need the control card to take some processing power off the main pc?

[Clive S]

Hi Clive
Could you elaborate on using PP without a mesa card? all the posts I read say that PP wont install without a mesa card.

Do you not need the control card to take some processing power off the main pc?

Ross I think I might have mislead you. When I said using the PP I meant parallel port You can use LInuxcnc with the parallel port and a simple BOB to do threading on the lathe with an encoder on the spindle.

I am at this time using just Linuxcnc with the axis front end. But I might have a go with PathPilot

But I am pretty sure you can setup PathPilot also with the parallel port and a simple BOB. Did you have a read at the link by cncbasher on the tutorials to set it up. Tutorial three mention setting up PathPilot with the PP.

[Ross77]

Ah that make sense. yes I have been al over the place trying to get up to speed with it all. I've been watching the Path pilot demos and it look really good. so quick and easy for R&D as well as production. it looks like it can be fussy on the PC used so the costs are slowly creeping up. Might just try Linixcnc and shift to Pathpilot later.

Thanks

[Ross77]

Making progress with the electrical side and think I know which route to take.

So the next major challenge is whether to use the existing cross slide lead screw or fit a ball screw! theses not much room for a ballscrew so would have to mount it to the side for the carriage.

Options seem pretty limited. any pros and cons of mounting the ballscrew off axis vs. using the leadscrew?