[Spinnetti]

so, not sure exactly what to expect, but find that after running maybe 300" of cutting over 12 9x1x.5 parts on my new last year 1100, my y axis zero is drifting, this latest time by .009, which trashed my part. I can check it at each op, but concerned about not keeping zero. Z seems ok, and have to double check the X... most of the motion is in x, with very little in y... Loose ballscrew or something? Its not overloading, but can it lose steps in a non-overload condition?

[WOTDesigns]

Have you tried putting an indicator against a fixed point and checking backlash (as another symptom) and seeing how much you can move the table while pushing on it? Could be a lot more than just ball screw. Could be loose screw on coupler, mount, gib, EMI, loose bad connection.

Try narrowing it down by looking at the trouble shooting guide in the Tormach manual. I do remember seeing steps on indicator testing. Lost steps are a symptom (and very rare). More likely would be 0.009 slop somewhere.

[WOTDesigns]

Also try popping open the box on the back hiding the Y coupler and try rotating it by hand. Try tightening the screws on the connector and the motor mount (as those are the easiest to fix possible causes)

[David Bord]

More than likely slipping stepper coupler. As mentioned make sure they are really tight. Wouldn't hurt to make a mark with a paint pen to see if it slips. If not that then maybe the Gibbs are too tight.

David

[Just Me]

To check for lost step attached is a program written by Tormach for the 1100...download and read instruction in programer header...If anyone needs a program for the 770 to check lost steps just ask

[BAMCNC.COM]

Could be lost steps during acceleration due to sticking gibs on certain moves during the run. Do you have the auto luber? What oil are you using? Are you using the the "unlocked" version of Mach, if so tick the acceleration down one.

[mike sr1]

It will make an unnatural noise when missing steps as well.

[BAMCNC.COM]

It will sound horrible if it misses multiple steps, but its possible to miss a few steps here and there on Acceleration and not hear it.

I think stock accel is 15 maybe and 110 velocity. you could put that to 5 and velocity to 200 and you wouldn't miss a step.

It's all a balancing act.

[nitewatchman]

Guys I had the same problem after running for about 18 months on my 1100. I could not find any mechanical problems and after having a machine built by another company in Georgia, I can quickly recognize the sound of the "stepper shuffle" if you are losing steps. After talking to the guys at Tormach, they suggested reseating the connectors between the controller and the motion control board. I went one step further and did all the connectors. The problem disappeared and all is well. I think that I at least was dealing with dirt, corrosion, detritus on the connecting pins.

On my machine, I can roll in on a fixture setup hole with a coaxial indicator, run parts all day, return to the setup hole, roll on it again and be within tenths to a thousandth or so.

Your experience may differ.

nitewatchman

[BAMCNC.COM]

Good point, I always tweak all my pins to the side on anything with a plug.

[Spinnetti]

Thanks guys, all really helpful advice! When I first got it EVERYTHING was loose, which was disappointing, but could be again... I'll check each of the things you mentioned...

Cheers.

[tbaker2500]

I'll second checking the coupler. The only time I've had drift was in the Z-axis and it was a loose coupler. It has to be pretty darn tight.

[TurboStep]

Good point, I always tweak all my pins to the side on anything with a plug.

This is definitely not recommended. The reliability of a connector has never been improved by "tweeking". If a connector is suspected to be causing problems then it should be replaced.
Tormach has gone to great lengths to produce a comprehensive manual which includes a detailed troubleshooting section. They say themselves that the manual is the place to start, so try there first.
Step

[BAMCNC.COM]

Your right. How can I have got millions if not billions of dollars worth of Wind Turbines to run when General Electric couldn't figure out the issue... Sorry, I guess a Tormach is more "high tech" and I've got it all wrong, I've only been doing it for 10 years, I'll learn eventually.

You are exactly the type of parts changer that we "In Wind" laugh at until your eventually fired. More money than brains, but like they say.. common sense isn't all that common anymore.

Tormach is not a God, they do not know everything, YOU need to learn on your own, YOU need to think outside the box, but let me guess... You probably wasted money on college aswell...

Rant over..

[Dsmed]

I was experiencing random lost steps on occasion with my 1100. I ended up tracing it down to an issue with the controller. I would load the g code file from my usb stick to the hard drive than open it in Mach. But when I left the usb stick plugged in it would cause random lost steps in ALL 3 axis at random times. Sometimes it was a couple thou in the x while other times it would be as much as a tenth in the z. Bad results when that happened, luckily I use aluminum soft jaws on my vices.

[BAMCNC.COM]

Another issue I've recently learned about is a bowing gib, the trick is to tighten it more than you think and keep it tight (maintenance more often)

[Spinnetti]

I was experiencing random lost steps on occasion with my 1100. I ended up tracing it down to an issue with the controller. I would load the g code file from my usb stick to the hard drive than open it in Mach. But when I left the usb stick plugged in it would cause random lost steps in ALL 3 axis at random times. Sometimes it was a couple thou in the x while other times it would be as much as a tenth in the z. Bad results when that happened, luckily I use aluminum soft jaws on my vices.

Hmm.. I do that too. Might be worth not doing just to make sure.

[MichaelHenry]

Another issue I've recently learned about is a bowing gib, the trick is to tighten it more than you think and keep it tight (maintenance more often)

What sort of problem does the bowing gib create?

Mike

[BAMCNC.COM]

I'm not the one with the issue, just a buddy has the issue. Seems like it misses steps, and is related to the X only as far as I know.