Need Help!- Geckodrive v202 jerky movement problem

[jetijs]

Hello all.
I have a problem and can't find an answer for that problem in forums. I have 3 geckodrive v202 controllers. One is working just fine, but the other two turn the stepper fine smooth only in one direction, if make them rotate in other direction, there is some jerky movement at the beginning and only then it starts running fine. It is odd, I tried all the controllers with the same motor and power supply. One controller works fine in both directions, but other two work fine only when turning in one direction. What could be the problem for this? I tried changing the pulse width but with no success, lowering the movement speed seems to improve things a bit, but just a bit, there is still many lost steps in that direction. I even tried to change the direction setting from active Hi to active Low - the problem is still there and still to the same direction. Power supply is an adjustable 24V 20A unit.
Thank you!
Jetijs

[jetijs]

I tried to disable the mid-band compensation using the appropriate jumper, this made the jerking a LOT less noticeable and improved things, but I still can hear some faint dissonance in the motor movement in the certain direction. In other direction everything rotates smoothly. This happens only on the starting of the acceleration and the ending of the deceleration.

[Mariss Freimanis]

Your problem will be located in your breakout board or the way Mach3 is set up:

1) Get a multimeter and set it to 'DC Volts'. Put the black lead to your PC ground and the red lead to 'Direction' on the drive. Cause Mach3 to jog CW and write down the voltage. Jog CCW and write the new voltage down. One reading must be less than 0.5V and the other reading must be 4.5V or higher. If not, your breakout board is malfunctioning.

2) If the G202 'Input Option Header' is set to 'Common 5VDC', Mach3 STEP output must be 'Active Low'. If the G202 'Input Option Header' is set to 'Common ground', Mach3 STEP output must be 'Active High'. You'll find this in 'Ports and Pins'. In 'Motor Tuning', STEP Pulse Width must be set to '2' microseconds.

Mariss

[jetijs]

Thanks Mariss
Will perform the test you proposed. I forgot to mention that I am using turbocnc and everything works fine using hobbycnc board and also if I use one of the geckodrives, the problem is showing only on the remaining two geckos.
Thank you!
Jetijs

[Mariss Freimanis]

OK, in that case:

If the G202 'Input Option Header' is set to 'Common 5VDC', the DC Voltage from PC ground to STEP input must read 4.5VDC or higher when you are sending no step pulses to the drive. If the G202 'Input Option Header' is set to 'Common ground', the DC Voltage from PC ground to STEP input must read 0.5VDC or less when you are sending no step pulses to the drive. Change your CNC program Step Pulse Polarity if the reading is incorrect.

Mariss

[jetijs]

What do you mean by "input option header"?
Can't find such a term in the manual.
Thanks

[jetijs]

Could it be that if there is not enough peak current on the 5V line, that's what is causing the problem? I use 24V power supply, but I get 5v using a positive voltage regulator that is fed by 24v and puts out 5V. I found out that putting a capacitor in parallel of the voltage regulator seems to solve the problem.

In my current setup the ground from the parallel port is connected to the ground of the power supply and the direction pin is putting out 0.7v when turning in one direction and 3.4v when turning in other direction. This does not change no matter if I set the direction pin setting on Hi or Low

[Mariss Freimanis]

My mistake; I misread it as a G212. Use the part that says 'Common 5VDC' from what I wrote.

Mariss