Y-Axis

[Jozua]

Today I have an unexplained dilemma.
I was doing some V Carving and all of a sudden, the machine went “off course” in its own direction. I stopped the program and reference all home.
This where the problem started. The Z- and X axis referenced fine, but the Y axis instead of moving backwards to the home position all of a sudden started to move forward in the opposite direction away from the home position.
My Machine is an EZ-Router running Mach 3
What can cause this?

[Bonch]

Check your wiring and you connectors. Shorts in the wiring can cause all kinds of problems. Make sure the connectors are not off the connections and touching the pin of the connectors intermediately.

[PaulRowntree]

Expanding on Bonch's comment ... Can you jog the Y axis both ways? if not, the DIR line for the Y axis is probably shorted high or low, somewhere between the PC and the stepper driver. Or the Y driver itself has developed a short.

[Jozua]

Thank you, that was my impression as well.
Yesterday I installed new connector blocks on both Y-axis stepper motors, making sure that there are proper connections between all the wires.

The strange thing is that it is very Random. Yesterday after installing the new connector blocks and after about a 20-min cut the Y-Axis went on its “Walk-about” again and failed to reference.

This morning it reference perfectly.

[Jozua]

Can you jog the Y axis both ways?

Yes if it reference home, I can manually jog it both ways. But when it starts to "wonder-off" during the cut, it fails to jog or reference.

[ger21]

Maybe a drive overheating?

[4DThinker]

This time of year I suspect static discharge. The only time I've ever had a cut do something other than what the G-code instructed it to do was when I was following the cut with a shop vac hose.

[Jozua]

Gerry, overheating also crossed my mind. At this stage I am so desperate I will not discount anything. What blows my mind I that on Friday 17 November I did an 82-min cut without any Y-axis trouble. On Monday 20 November after only 20 minutes the Y-axis started its strange behaviour. Strange enough none of the stepper motors felt warm to the touch after I encountered the trouble. I was cutting actually at snail’s pace V Carve at 40 inches per minute and profile cut-out at 50 inches per minute for a machine that is capable of about 300 inches per minute.

4D, remember its is almost summer in South Africa and this time of year we do not encounter any static electricity. Humidity here is about 25 to 30% and temperature between 28 and 35 degrees Celsius (no clue what it is in Fahrenheit). During all the cuts the dust extractor was not switched on. If it is static electricity, I have no clue where it is coming from. The machine is properly earthed.

Out of desperation I am going to try one last trick. I have a new spare stepper motor. So, I am going to replace one of the current Y-axis stepper motors (luck of the draw, I guess) with the new one. If the problem still persists, I will replace the other one to try and determine if one is overheating.

Thanks for the advice and suggestions. I am in a bind, I have to complete 5 x Mother’s Keepsake Boxes in time for Christmas gifts but at this rate it will take me 2 years...........

[dwilli9013]

overheating also crossed my mind. At this stage I am so desperate I will not discount anything. What blows my mind I that on Friday 17 November I did an 82-min cut without any Y-axis trouble. On Monday 20 November after only 20 minutes the Y-axis started its strange behaviour. Strange enough none of the stepper motors felt warm to the touch after I encountered the trouble. I was cutting actually at snail’s pace V Carve at 40 inches per minute and profile cut-out at 50 inches per minute for a machine that is capable of about 300 inches per minute.

I would actually lean more towards your drive for the stepper motor. I have never experience a stepper motor failure but have dealt with quite a few drive failures. Inside your control box you might want to check if you have any sawdust build up and be certain the fans on your control cabinet are functioning. Gieko stepper drivers are notorious for overheating when place in a non fan cooled cabinet.
Just a shot in the dark here. Hope you get it figured out.

[Jozua]

Inside your control box you might want to check if you have any sawdust build up and be certain the fans on your control cabinet are functioning

The control box is cleaned with a small compressor every Friday (Standard routine maintenance since 2008) I can assure you NO dust at all. I checked both fans they are working fine, also I clean the outside foam covers of the fans every day before I switch on the machine.

Thanks for the reminder but it is covered, any other suggestions would be appreciated.

[Jozua]

I think the problem is solved, I have run the machine for 2 hours now without the problem occurring again.

I tightened all the screws of the Y- axis terminal block on the BOB, also followed the directional wires to the stepper motors and re-tightened that as well. For good measure I replaced the Gecko drive and installed another extractor fan in case of possible overheating.

Thanks for all your assistance.