Need Help!- Ongoing Saga of a CNC Gone Crazy

[IQChallenged]

Reading post #47 of this thread suggests that I know precious little about the voltage sources (true). But I never actually got around to finishing the experiment with the BOB bypass because I got tired of breaking those little wires. The only test I ever got done was to try it with nothing but the DIR and SIG, no power.

[Mariss Freimanis]

Bill,

I should always be questioned. It would be a mistake to ever let my head grow so big that I start believing my word is the final authority and beyond question. All thinking and innovation stops when that happens. Rather, I invite people to question everything I say; it is then my obligation to explain why a conclusion is made. The explanation is either solid and stands or is wrong and falls.

In this instance a resistor was burned. The resistor is accessed from the outside world via the DIRECTION terminal only. It is in series with the optoisolator LED which exits the drive via the COMMON terminal. There is no credible scenario I can create to account for the resistor being burned except for the one I did; high voltage touched the DIRECTION terminal.

Most other failures are more ambiguous because of the number of possible causes and their permutations. This one is not; it's too simple. Resistor in series with an LED. Both ends of the series combination exit the board with no other connections anywhere.

Once the impossible is eliminated, the improbable may be the only explanation.:-)

Mariss

[Mike Stevenson]

Originally Posted by Mariss Freimanis I should always be questioned. It would be a mistake to ever let my head grow so big that I start believing my word is the final authority and beyond question. All thinking and innovation stops when that happens. Rather, I invite people to question everything I say; it is then my obligation to explain why a conclusion is made. The explanation is either solid and stands or is wrong and falls.

Mariss,

I agree with you.

[Mariss Freimanis]

Mike,

I've always liked this one: When making a discovery, the first words aren't "Eureka! I have found it!" but rather "Hmm.. That's interesting..."

Mariss

[Mike Stevenson]

Originally Posted by Mariss Freimanis Mike, I've always liked this one: When making a discovery, the first words aren't "Eureka! I have found it!" but rather "Hmm.. That's interesting..." Mariss

Good advise.

[asuratman]

Hello,
What is G540? This is 4 axis stepper driver? When they will be on the market? Will gecko release 4 axis servo? Because I have 4 DC servo motor with G320. This question maybe out of subject. Thanks. Aristo.

[Mariss Freimanis]

Please see the last few posts on the "Cheap Drives" thread in the Geckodrive forum.

Mariss

[asuratman]

Thanks. Aristo.

[Clockwork]

I built a BOB equipped with LEDs to display the Step and Dir outputs. (had to put pulse stretching timers on the step leads to make them visible)

Once completed I was seeing a flurry of activity on the leads every 20-40 seconds without any CNC stuff running. This was caused by the HP printer software I had loaded which apparently goes out looking for a printer at this interval. It can really screw up your CNC traffic on the printer port.

Removed the software and all was fine.

Don't know if this will help you - just throwing it out as another idea.

[IQChallenged]

As of today my problems have been solved. Mariss discovered a blown resistor in my Gecko and fixed it for me. He paid for the parts and the labor and diagnostic time and paid the postage back. I am grateful.

That left the nagging problem of cutting deformed parts by following paths not programmed. My very first inclination was a lose gear. Why? One of my very first posts after getting my machine running had to do with oval shaped circles. Gerry knew right away that it was due to backlash. The backlash that I found was a lose gear. So I'd been there before. But this time when I checked it I didn't twist on the gear hard enough so I did not find the problem which was-- a lose gear. I even swapped out the motors. But I still had "a" problem. But the problem was related to the blown driver which still worked "a little bit".

So I'm half embarrassed. But when you think about it you've got to agree that whatever you find will have you saying "I knew it had to be something simple". When you come on the forum and start asking for help you have to accept that people are going to learn about your weaknesses. That's okay with me.

Thank you everyone. Come see me. www.ProjectCNC.wordpress.com

[LeeWay]

Most of the time when something doesn't work right with these, the problem is usually pretty simple once you learn how to best troubleshoot these things.
It's a little harder to do when there are compound issues.
You need feel no shame here. I once worked on a control box for a week trying to figure out a problem. I had posted to a couple forums. It turned out to be two bent pins in the motor connectors that weren't making contact. Extremely simply, but excruciating to track down. The only reason I found that is this was the first thing that I took off as I was going to completely tear the entire control box back apart and use all new wire again. I guess I did get lucky that it wasn't the last step I did.

Then I killed 5 203V's touted as nearly unkillable. They were repairable, but I was switching the DC side of the power supply. It did seem logical to me, but I was using a PS that was near max voltage for the 203's.

Then I zapped a Zylotex the night I first tested stepper motors ever. It was a short test so to speak. I brushed a poorly taped motor wire up against the control box and a bare wire was sticking through and that drive was repaired by Jeff.

So really simple things can cause tremendous stress and head scratching on these machines built usually with parts made by about 20 different manufacturers. No single source for support.
The good news is that the longer you do this, the more you will learn. I learn about a lot of faults simply from reading this forum and threads like this. Simple solution? Sure, it's easy to fix once you know WTF is wrong.

Congratulations on getting it going. Now if you loose any sleep, it should be because you are dreaming up new parts to be cutting.