Howdy LinuxCNC-ites, possible new user....

Hi all

I am seriously considering moving from Mach3 to LinuxCNC having tried EMC a long while ago. However I want to be sure I can do pretty much everything I do in Mach, in LinuxCNC.

My machine is a 2400x1200 Mechmate. I currently run 640Oz-in Nema 34 steppers with AM882 Leadshine drivers. A PMDX-126 serves as the BOB along with an ethernet SmoothStepper. I know the Smoothstepper won't work but, as far as I know, everything else will. Along with that side of things I also have a Hitachi X200 VFD controlled by Modbus that controls a 2.2Kw water cooled spindle.

On the Mechmate I have 3 control boxes - each box contains a Start, Pause and Stop button that interacts with Mach3 to do just that. There is also an emergency stop button. The Z control box has an additional 2 way switch and an additional pushbutton for Z touch offs. The 2 way switch lets me choose between a single touch off with a movable plate and an multi touch off routine that first starts with a moveable touch off plate however the machine then moves to a fixed plate to get the length info. Any subsequent tools requests only needs me to change the tool then press start and the machine with again go off to the fixed plate to find the Z difference before continuing. This functionality is via the 2010 Screenset I am using plus utilising different inputs on the 126 to drive the correct macros to do the job.

One more thing... I am using a Mach3 brain to control the indication side of my safety features. The brain uses one input on the 126 to flash a 24V LED in certain sequences depending on the condition, those conditions being waiting for machine start, machine pause, machine, stop, AM882 stall and E-stop status.

There are a number of Mach3 macros in use as well.

So, if you got through all that, does anyone have any thoughts as to what of the above *can't* be done in LinuxCNC? Where would be the best place for me to start researching these things? Lately I have been getting information overload as I search for the answers so something structured would be very very helpful.

I will probably have a lot of questions as I transition so please bear with me.

Cheers
Bruce

Thanks JT

Your question re the SmoothStepper... I a) needed more inputs than 1 parallel port would supply and b) wanted to put the PC away from the machine and didn't have a long PP cable and c) alot of others were using it. The SmoothStepper is one of the reasons I want to switch, it is a pain in the butt at times and besides, me and windowz have a love hate relationship.

I didn't know squat about the Mesa cards, I originally thought they were for servo's not steppers. That and the "american" scene seems to concentrate on the PMDX arena along with Gecko drives. I have since found alot more available in the EU market as well as different US manufacturers.

With that said I am now seriously considering the Mesa cards, $360AUD buys what I need and I should be able to recoop that from selling the 126 and SmoothStepper. Just one question, does the 5i25 only need one parallel port?

I am going to build a sim version of LinuxCNC and try out everything I want to do. If I am felling adventurous I might try my hand at a custom GUI to mimic the Mach3 screen set I am currently using, just something to make me more comfortable. This would mean learning a new language (Python) and how to use Glade and GladeVCP, but hell you only live once

I am sure I'll be back with more Q's.

Off to find Glade tutorials!

Cheers

Didn't expect that - will have to read as much as I can about 5i25 and 7i76 methinks....

Thanks for links, I will definitely take part in those.

Cheers

Got it now and understand better. Currently installing Ubuntu 12.04 with LinuxCNC 2.7 as my test bed.

Got my machine connected to LinuxCNC tonight and had the Z and Y moving under the stepconf tests and moving smoothly at that. Better then Mach ever did in my opinion.

Having problems with my X (2 steppers) but hope to get that sorted tomorrow after work. Big loud crunching sounds is not what I want!

Alrighty, having issues.

In particular, my Y motor is not playing ball. I have setup stepconf with ports & pins the same as Mach3. With my Y motor it will only move in single steps but in the right direction. If I invert both Step and Dir it flies at 18000mm/pm but goes in the wrong direction to that pressed on the keyboard, meaning I press left and the Y goes right. Not sure what is happening here, especially with the single step per press when it goes in the *right* direction, press left, it goes left. LinuxCNC however thinks it is going @ 18000mm/min.

The X is basically doing the same. On the X I am sharing the X output on 2 drives Step pin 2 is the same as Step pin 4 and Dir pin 3 is the same as Dir Pin 5. To make one motor the reverse of the other I have to set both step and dir for that motor inverted. If I choose pins 4 & 5 both motors runs at the same speed but in the wrong direction (as above). If I set 4 & 5 "normal" and 2 & 3 inverted one motor spins normally and the other steps as the Y does.

The only one that works as advertised is the Z

Anyone have any ideas??

it flies at 18000mm/pm but goes in the wrong direction

Go into your .ini file and reverse the sign of SCALE for the axis you are working on.
If the SCALE = 800
change it to
SCALE = -800

Rick G

Thanks Rick, just had dinner so will go out and do that shortly.

Love this forum!!

Cheers