Need Help!- EMC2 software setup help

[jon_cnc]

I am building my own CNC machine that is controlled by LinuxCNC's EMC2 program. I am using a parallel port breakout board connected to 4 stepper drivers (all from probotix.com). It is a 3-axis gantry machine with 2 motors for the x-axis. My question is twofold:

1) how do configure EMC2 to move the x-axis motors in sync? I was thinking that I would change the pinout in the stepconf wizard to have x-axis outputs instead of the a-axis outputs. (resulting in two x-axis outputs)

2) how do you configure EMC2 to run Probotix equipment. As in, what specific values are associated with Probotix drivers that need to be entered into stepconf? Also, what is the correct pinout configuration for the Probotix breakout board in stepconf? (I can probably figure this out through trial and error, but I'm new to EMC2 and some advice would be helpful)

Thanks!

[CarveOne]

It is possible to slave the X axis motors in EMC2 but it is not easy to find the info. I've done it, it works well, and will need to find where I put the notes about it. As I recall, you will use the xyz machine configuration, not the xyza machine configuration.

CarveOne

[beermkr]

I just went out and played with the Stepconf wizard and i bet that you can use the XYZ setup and tell it to put the x step and x dir signals out on the A pins. It should (guessing here) put duplicate info our on both sets then.

R/

[CarveOne]

Originally Posted by beermkr I just went out and played with the Stepconf wizard and i bet that you can use the XYZ setup and tell it to put the x step and x dir signals out on the A pins. It should (guessing here) put duplicate info our on both sets then. R/

That's pretty much what I remembered doing two years ago. My memory about that isn't as sure about it as it used to be though.

CarveOne

[rk396]

I've just recently switched to EMC2 and had to do this very thing. In stepconf just set the pin outs for the slaved motor to the same Axis. Depending on how the motors are installed, the step and direction may have to be inverted.

[CarveOne]

Start Stepconf Wizard with the xyz router machine configuration.

On the first configuration screen set Axis Configuration: XYZ

On the second configuration screen set Parallel Port Setup as folows:

Pin 1 = Unused
Pin 2 = X step
Pin 3 = X direction (check mark)
Pin 4 = X step
Pin 5 = X direction (check mark)
Pin 6 = Y step
Pin 7 = Y direction (check mark)
Pin 8 = Z step
Pin 9 = Z direction (check mark)

Note that while in the Stepconf Wizard you can only test run one of the X axis drives, so it will cause racking. After making these settings save the configuration and test the drives outside of the Stepconf Wizard. I recommend setting the jog rate to a slow rate for the initial testing to see that the drives both move in the same direction without racking. I hard wired the slave drive so that it is reversed from the X drive and the configuration is the same for both motors. If you want to keep the motors wired the same way just uncheck the box for Pin 5.

You will need to have the gear ratios set correctly in Stepconf also. The slaved drive is assumed to be the same as the X drive.

CarveOne

[jon_cnc]

Thanks for the help. CarveOne, what do you mean by not inverting the output for the second x-axis motor? If EMC is outputting two sets of x-axis commands, why can't the motors be wired identically (since they are moving as one)?

Also, is there any Probotix driver specific information that I should be aware of? What about the x-enable, y-enable, and z-enable pins on the breakout board? Are they the digital outs in stepconf?

[Regnar]

[QUOTE= CarveOne, what do you mean by not inverting the output for the second x-axis motor? [/QUOTE]

This statement is dependent on your type of machine. Most with 2 X motors are usually running a gantry router with rack and pinion. This would mean that both motor shafts would be point towards the center of the table. If you told both motors to turn clockwise. One motor would go one direction and the other would go the opposite. Now if you are using screws like a Solvyia (sp) build then you have nothing to worry about.

[CarveOne]

Originally Posted by jon_cnc Thanks for the help. CarveOne, what do you mean by not inverting the output for the second x-axis motor? If EMC is outputting two sets of x-axis commands, why can't the motors be wired identically (since they are moving as one)? Also, is there any Probotix driver specific information that I should be aware of? What about the x-enable, y-enable, and z-enable pins on the breakout board? Are they the digital outs in stepconf?

I don't have any experience with Probotix drivers or breakout boards. Sorry.

Regnar is right about the screws vs R&P. In addition, it's also possible to use left hand screw on one side and a right hand screw on the other side of the gantry. Most of us use screws with the same twist direction, typically right hand I would assume.

You have a choice to wire the motors the same (as they would be if they come pre-wired) or reverse the wiring of one coil in the slaved motor. You just toggle the check boxes in Stepconf Wizard for the two slaved motors so that they both run in the correct direction at the same time. Whichever combination works for your machine configuration.

CarveOne