[xspyke]

I'm sorry if this is a little long. I hope this helps someone else.

This is what I've been chasing down for the last day and a half. I never noticed the problem until I had to cut thick object (1 inch) with multiple passes(0.02"/pass). The x axis drifted 3/16" by the time it hit the depth of 1 inch.

You may ask what software are you using, what are my settings, what drive.

Mach3 software settings:
10000 steps, 200 inches/min, accel set to 50,pulse width and duration set to 2.

Gecko 540 drive. (I love the design and packaging)

I started by making sure my z axis move up and down perpendicular to the table. I checked the x and y movement with a dial indicator. I found the y gave consistant reading when I move 3 inches up and back 3 inches. I did not get the same results with the x axis. My readings increase by .003"each time I move it left-right-left.

I then started playing around with software settings. I tried changing the acceleration, pulse width, velocity, backlash. sherline setting. No success.

Change the 6 ft 25 pin cable with a 3 ft cable, moved the power supply away from the cables and Gecko drive. No change.

Then I re-installed Mach3. No change.

I checked my bios settings. All the setting were correct.

I swaped the the x and y cables that connected to the Gecko 540. The problem followed with the x port of the drive. So, that told me my machine is good.

Now is it the PC or drive? I read alot last night about losing step. I thought about getting another graphics card. But, before I go and spend more money on this hobby. I had one last thing to try. Swap the A axis board with the X axis board. Run the part again. It came out perfect!

I'm so glad I purchased the 540. I had a spare drive when I needed it. Now I have to see about relplacing the defective drive board.

[guru_florida]

What this is, is a testement to good deductive troubleshooting!

Cheers!

[Mariss Freimanis]

Please try "Sherline Mode" in Mach3. It should straighten out the funny behaving drive.

Mariss

[rgramza10]

If have been having nearly the same problem. Skipped x steps and was pulling out my hair. "Sherline mode" fixed the problem. Thank you!

[Mariss Freimanis]

Sherline mode only widens the step pulses. The G540 shouldn't need it if it's working normally. If you can, return it for evaluation, if it has a problem we will fix it for free including return shipping.

[rgramza10]

Hi Mariss, thank you for the reply. My Gecko is running so well that I hate to remove it from the control cabinet and disturb the system. Other then my step pulse problem the drive is absolutely perfect. The compact size and simplicity and now repeatability! As a double check should I increase my step pulse from 3 microseconds in Mach 3 to 5 microseconds? Would you recommend any other checks. I went through all grounding possibilities. I have no ground loops. My motors and belts are completely in sync with no binding. Thank you again. Perhaps in the next few weeks I will take you up on the return. All the best Ron Gramza