Thinking of buying a GREX G100, but need a few answers

[Adee]

Hi
Sorry to ask these questions, I m about to ask, if they have already been discussed, but I have been reading through these cnc forums and can’t get a satisfactory answer about the G REX G100.
I am looking into retro fitting an Emco VMC 100 vertical mill with 10 station tool changer, because of reliability issues of the driveboards and to vamp up the spec of the machine, eg. Usable 3D contouring feedrates 2 to 3m/m, rapids about 5m/m.

BTW I have limited knowledge on retro fitting cnc, so please bare with me on this, thank you.

I was thinking of going down the route of Mach 3, GREX G100, and Gecko G203V’s linked to Nema 34 stepper motors.

Question 1.
Do you think this is a wise choice software/electronics?

Question 2.
I have been told I need a PLC board to control the toolchanger would this still be necessary if I used the GREX G100?

Currently the tool changer works off the main spindle motor with an encoder and 3 proximity switches to rotate the t/changer to the selected position, after the Z axis moves into a set position to clear the backend of the tool from spindle nose.

So when t/changing, the Z axis moves up to its home Z position, orientates spindle, then Z axis moves up another, say 50mm to clear backend of tool holder and to engage a bevel gear to drive the tool changer. Then the spindle drive motor rotates at a set speed and amount of revolutions for required tool selection position, And then Z axis retreats back to home position.

Question 3.
I read somewhere the GREX G100 wasn’t to great at controlling 3d machining (3 axis point to point program scanning)
Does anyone know if this is fact, or would this possibly occur if the coms links are running slow or have issues, which leads me on to my next and final question.

Question 4.
Is connecting the GREX G100 up to a PC with Mach 3 via USB or Ethernet, difficult to do or is it almost plug & play, just that I heard some user having problems getting the unit to work properly.

Thanks in advance for any input, ideas and info,

Adee

[ger21]

Originally Posted by Adee Question 3. I read somewhere the GREX G100 wasn’t to great at controlling 3d machining (3 axis point to point program scanning) Does anyone know if this is fact, or would this possibly occur if the coms links are running slow or have issues, which leads me on to my next and final question.

There's a lot of info about this on the Mach3 Yahoo user group. Apparently, 3D contouring at high speeds with a Mach3 controlled G100 does not always work very well, but can vary by the application. I'd suggest searching through the G100 posts on the Yahoo group for the last 6 months.

[Adee]

Cheers Gerry, I will have a look on there now.

Adee

[samco]

Are you used to mach? I have not used it so take everything I say with that in mind.


http://www.linuxcnc.org/
Have you thought about emc2? How high of stepping rates do you need? Do you really need an external step genereator? I say emc because it has ladder logic built in (classic ladder). 2 printer ports would be a lot of i/o. Otherwise - you can get external step generators like pico systems

http://wiki.linuxcnc.org/cgi-bin/emc...orted_Hardware

Take a look at it.

sam