So, I bought a chinese desktop engraver machine (yes I know, I am cheap)

I bought for offline serial numbering for a part we run. Bought Mach3, got my serial macro to work great.

The problem is, I ran like 50 parts with extensive engraving on it and all of a sudden the "X" axis is not repeating. It some times moves .020" to .125" when I reference back to Zero. Basically cannot rerun the part on the machine if I need to drop the engraving depth.

I thought maybe the coupler on the stepper motor was slipping so I took it off, ground a flat on the screw and put a set of set screws in the coupler to clamp on the flats of the shaft. Ran it again, and with one run, it's off by .020"


So I guess I am asking for troubleshooting suggestions....

Could it be backlash?
Could it be the controller? (Is there a plug and play replacement board one would recommend for these units?)
Could it be the screw? (Is there something someone would recommend for a better screw system on this unit?)
Could it be the stepper motor? (is there better replacements here also?)


Any direction and insight would be great for those that have been playing around with these things.

I have an upgraded spindle coming (24K rpm), and would really be nice to nail down this lack of repeatability of this thing.

Thank you,

Mike in MN

If it worked for engraving 50 parts it would seem like something is loose or an adjustment of the x axis components are required. Can you post some pics of the axis and maybe some info on the machine so someone can have a look and
offer advice.

RICH

Trying again... (It keeps stalling when I try to post)

Here are 2 pics....(stalls while trying to attach)

http://www.cncbasics.com/pic1.jpg
http://www.cncbasics.com/pic2.jpg




Here is the link to the engraver... http://www.ebay.com/itm/CNC-ROUTER-ENGRAVER-MACHINE-DRILLING-MILLING-3020-q-/140562441574?pt=LH_DefaultDomain_0&hash=item20ba2ca566

I am wondering if maybe it's losing a signal here and there with the wiring also???

Thank you,

Mike in MN

Try slowing the motors down. Look for internet connecting programs. Try searching post for lost steps.

More than one person has had to replace the blue box with a Gecko 540.

Hal

Look for internet connecting programs.

Internet connection programs???

Try searching post for lost steps.

Post, the NC program?

Thank you,

Mike in MN

Quote from: Hal on October 22, 2012, 08:41:40 PM

Look for internet connecting programs.

Internet connection programs???

Quote from: Hal on October 22, 2012, 08:41:40 PM

Try searching post for lost steps.

Post, the NC program?

Thank you,

Mike in MN

the only thing running on your control computer should be mach 3, no internet connection, no anti virus, no background tasks, not much of anything as they can interfere with mach.

You could also try setting your velocity and acceleration lower by half and see if that makes a difference.

On my machine I have to clean and lube frequently or I'll begin losing steps.

just a few suggestions, good luck finding the problem.

John

Quote from: mn_mike on October 22, 2012, 09:50:15 PM

Quote from: Hal on October 22, 2012, 08:41:40 PM

Look for internet connecting programs.

Internet connection programs???

Quote from: Hal on October 22, 2012, 08:41:40 PM

Try searching post for lost steps.

Post, the NC program?

Thank you,

Mike in MN

the only thing running on your control computer should be mach 3, no internet connection, no anti virus, no background tasks, not much of anything as they can interfere with mach.

You could also try setting your velocity and acceleration lower by half and see if that makes a difference.

On my machine I have to clean and lube frequently or I'll begin losing steps.

just a few suggestions, good luck finding the problem.

John

I do have a usb wi-fi adapter on it, but that's it.

I wonder if that will make a difference.

I will unplug it and give it a go tomorrow.

Thank you,

Mike in MN

Measure the amount of backlash for each axis. I could not see any adjustments for it in the pictures.  
RICH

More than one person has had to replace the blue box with a Gecko 540.

Hal

I'll second this.  Mechanically, these Chinese machines are OK, but the electronics are junk.  If the motors are under 3.5A, put a G540 on it.  It's the best $300 you'll spend.

Windows XP Professional System Optimization Guide:

Try going through this file.