forum.cncdrive.com

Hi,

I would really appreciate some help with jerky motion on my milling machine.

I've read many post and tried lots of different options and I still have the problem.

So, if I hold the arrow keys down, then motion is smooth but after 5-10s movement stop (i am still holding the arrow key down) and after 1s the movement continues and then again stop.
If I push the RefAllHome button then the motion is smooth (this I find odd).
Motion with virtual mpg is smooth.

When i say to command for example : G01X-50, G00X-50 the movement is divided into several parts and movement is not smooth, this applies to all axies.
I tried to change the acceleration and velocity but nothing happend.
Also if I type:
G64
G00X-50 (in mm)
then then the motion is jerky/divided to more motions.

I use DB25 parraler breakout board, win XP, Nema34 12N.m and drivers - DQ860MA

Thank you for all the advice

What controller are you using, and what version of Mach3?

Hi, I am using DB25 parraler breakout board and Mach v2.0

What CNC Drive controller is the breakout board plugged into?

From the computer (Windows xp) the breakout board is connected via a parallel cable and drivers (DQ860MA) for motors (NEMA34) are connected to this control board.
I thought that problem may be in this board so i order a new and after conection problem is same. Maybe i should try to upgrade mach3 to newer version.

Then you are at the wrong forum.
You are using the computers parallel port.
This forum is for people using CNC Drive motion controllers.

Your problem is most likely due to the PC. Open windows task manager, and monitor CPU usage while doing your jogging test.

Well, thank you very much for the advice, I hoped that someone had encountered such a problem

It is likely that your computer is too "weak" for the LPT port driver to work properly with good latency with smooth motion.
You could replace the LPT port with one of our motion controller, then the time critical tasks are no more made on the computer but on the motion controller.
You could then connect the motion controller to the computer via USB or ethernet and the motion controller gives you a LPT printer port connection which you can connect to your control box.