Tool offsets change after restart (Resolved)

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polaraligned
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Re: Tool offsets change after restart

Post by polaraligned »

Forget the home switch...
If you set all your tool offsets based on tool #1 as you said, then the rest of them will be relative to that tool regardless of whether your home switch works or not. You don't even need a home switch. You can home anywhere in the travels and the software will properly execute the tool offsets.

This sounds like you are loosing steps or have a mechanical issue.

After running a few jobs on the machine, remeasure the offsets and see if they have changed before powering down. I would check the machine for repeatability.

As for you dropping your ethernet connection, make sure your ethernet drivers are up to date and get a new cable.
Dbean
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Re: Tool offsets change after restart

Post by Dbean »

Polaraligned
I thought the same thing! If I set up Tool #1 and measure all my tools It will run all day and never lose zero. Repeatability is .0005" or less.
Marty explained earlier that the Homing has something to do with it though. Not sure how that works.
Here's my issue:
I Home the machine, set tool #1, measure all tools, make parts, turn off machine, next day start and home machine, ISSUE All tools are now off by .005" to .020" and very random(some are off +.008 some are -.015" etc), spend the next hour reseting all tools. I have a spreadsheet I kept with a weeks worth of start up measurements/how far off they are, and they are never consistent.
For a short time I thought it was a mechanical issue but once I have set it up it will run 200-300 parts in a day and be spot on.
tblough
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Re: Tool offsets change after restart

Post by tblough »

Your home is not accurate. All you need to do is redo your part XYZ 0 after homing. Your tool length relations are still correct only your Z 0 is off. You don't need to reset your tools.
Cheers,

Tom
Confidence is the feeling you have before you fully understand the situation.
I have CDO. It's like OCD, but the letters are where they should be.
martyscncgarage
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Re: Tool offsets change after restart

Post by martyscncgarage »

Just so you understand how commercial CNC machines work,
They home to a switch and then they back off and hunt for the Z index pulse on the servo encoder.
Very few step and direction drives have this capability. I know DMM Dyn4 and Dyn2 have it.

You might setup an indicator and rehome the machine over and over and check for repeatability.
Did you turn your proximity sensors 90 degrees? Make sure the target is WITHIN the sensing distance range of the sensor. The closer the better.

Marty
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
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polaraligned
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Re: Tool offsets change after restart

Post by polaraligned »

Dbean wrote: Thu Dec 03, 2020 8:25 pm I start up the machine and use tool 1 to set 0 for x and z. My other various tools will be off by 0.01" to 0.03" and I have to re measure all the tools. It's a real pain for drills and boring bars...
Tom, this is a quote from the OP's first post. He is setting tool 1 (which he stated he uses as his reference tool) to Z and X zero after starting up, but the other tool offsets are off....If he is doing this, it is definitely not a homing problem.

If the OP is doing what he stated a few posts ago, then it is a homing problem because now he does not state that he is setting tool 1 to zero after start up.

So we need the OP to tell us which is correct?
tblough
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Re: Tool offsets change after restart

Post by tblough »

Regardless of what he's setting, if the tool offsets ALL change by the same amount, it's a setup problem. If the tool offsets change by various amounts, then he's loosing steps in the Z.
Cheers,

Tom
Confidence is the feeling you have before you fully understand the situation.
I have CDO. It's like OCD, but the letters are where they should be.
Dbean
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Re: Tool offsets change after restart

Post by Dbean »

Ok, ok ok...
I turned the sensors 90 degrees. Got about an average .0001" variation after re homing 20 times. 12 of those times it was zero.
While I was indicating homing and checking for anything loose, like a loose screw behind the wheel, I indicated my tool holder.
Background:
I use the ECI gang tools including the Posi-lock version on opposite ends of the gang table. Pretty sure I provided a photo earlier. Just as a sanity check I slid T0101 in the holder, tightened it down and indicated it. Loosened it, off, back on, tighten and measured again...Face smack. Not because the flies buzzing around. Damn thing was .026" off. Did this about 10 times. Actually had to get out the .001" indicator there was so much play... :lol: :lol: :lol:
I need to do some checking with ECI and see if this is within spec. but dang... It's a dovetail style holder that's suppose to lock into place and be repeatable. My Accusize QC tool post on my little Chinese mini lathe will hold under .001" :roll: .... I'm beside myself guys. Explains the whacky numbers in X.
As always the help and support is great but I'm calling this issue solved. I think I'll remove the ECI Tool hold and use it as a fishing weight. Might even tie it to my bumper and drag it to the lake. You know, round the edges a little...
I'll follow up as to if this is a normal amount of play for this holder.
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