Topics

1

General Mach Discussion / Synchronized I/Os over Modbus (?)

« on: February 13, 2020, 08:26:47 AM »

Hi all,

I am trying to wrap my head around the following problem:
I have multiple devices controlled over i2c that I want to operate according to the position of the 3 axes of a my cnc setup.

To visualize the problem one could imagine to have the following situation:
- 4 nozzles attached to a CNC setup
- the CNC moves the nozzles around over a plane
- according to the current position, each nozzle is turned either on or off

As I see it, one would need two sets of data:
1) toolpaths, fed to Mach3 as gcode
2) 2D matrix of 0s and 1s representing the raster "image" to be printed, loaded on a PLC
and
3) a way to communicate the position of the axes from Mach3 to the PLC and, consequently, operate the devices nozzles consistently

Given that all the assumptions above make sense, would Modbus be the best channel for transmitting such information?
Or do you know of any better way to reach a similar result?

Thanks,
Pietro

2

General Mach Discussion / G64 parameters?

« on: February 03, 2020, 09:06:15 AM »

So, it turned out that CV distance >0 and consecutive motions along the same axis (see code below) cause the machine to "thud" (at least in my case).
As for some routines I would like to still be able to set the CV dist >0, is there a way to set it through gcode?

i.e.:
...
G64 D0 // set dist = 0
G01 X100
G01 X200
G01 X300
...
G64 D1.5 // set dist = 1.5
...

Does anything similar exist in Mach3?

Pietro

3

General Mach Discussion / How to smooth out motion when using M10/M11

« on: January 31, 2020, 10:31:05 AM »

Hi everyone,
I have been using Mach3 for a while now and on a few different projects, but I never managed to get past the following issue:
I'm turning on and off some outputs while moving along one axis (say X), which happens to be a gantry (2 motors slaved through Mach3). The outputs switch as intended, but the motion shows a clear "hick-up" every time, often leading to the two motors going out of sync and ending in the gantry getting stuck.
As the problem cannot be mechanic (everything runs smooth at much higher speeds when outputs are out of the equation), my assumption is that the main cause might be some power spikes occurring during the M10/M11 commands.

Did anyone encounter similar issues? And, more in general, do you think that adding properly dimensioned capacitors could help smoothing out the motion?

A brief overview on the electronics:
Motion controller: UC300
Drivers: Leadshine EM705
Motor: Hybrid stepper motor, 4A 2Nm
PSU: 10A@48V

One more note: the outputs switched on are powered by a second PSU.

Any hints/suggestion would be appreciated!