325 limit on home?
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325 limit on home?
I'm still working on getting my oak board setup up. I got the servo's working, I homed and everything seemed to be working. I started to work on the spindle, after a running into a few stupid problems, I got that to work as well. This happened across days with multiple power cycles. Right after getting the spindle to work, I homed. Z went home, hit the + limit switch which is home, moved back down a little bit, then homing stopped and I get a "325 limit: job cancelled" From what I have found, 325 is a soft limit? But I have soft limits set to zero. And why would that trip while homing?
Thanks.
Thanks.
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Re: 325 limit on home?
It is a hardware limit trip. Most likely you did not get a clean trip or break from the Z+ switch, so it appeared to trip (open), clear (close), then trip (open) again.
When homing off a switch that is also a limit switch, you get a one-time pass to trip the switch without it being considered a limit trip. If it trips a second time, that causes a 325 error.
You can use the PLC Detective Logic Analyzer to watch the limit inputs and see if there is any bouncing (though it is possible for a trip event of just a few milliseconds to cause the program cycle to be cancelled, without appearing on the logic analyzer). For good measure, watch MEM85 "LimitTripped_M" in addition to the six limit switch inputs.
For more about the PLC Detective Logic Analyzer, see http://www.cncsnw.com/PLCDetectiveHowTo.htm
When homing off a switch that is also a limit switch, you get a one-time pass to trip the switch without it being considered a limit trip. If it trips a second time, that causes a 325 error.
You can use the PLC Detective Logic Analyzer to watch the limit inputs and see if there is any bouncing (though it is possible for a trip event of just a few milliseconds to cause the program cycle to be cancelled, without appearing on the logic analyzer). For good measure, watch MEM85 "LimitTripped_M" in addition to the six limit switch inputs.
For more about the PLC Detective Logic Analyzer, see http://www.cncsnw.com/PLCDetectiveHowTo.htm
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Re: 325 limit on home?
Ok, I'll look at PLC detective tomorrow. Or, I'll just through a scope on it. Or both. Is there any software debouncing? I assume I can through a capacitor on the limit switches for a simple debounce circuit? The limit switches are new, but there cheap automation direct limit switches.
Now that I think about it, I had my spindle driver wired up wrong. From reading the manual on it, I thought that it needed 24v to be applied to the inputs. This was wrong, but I wonder if I accidentally bonded the two 24v power supplies together. Maybe my 24v is noisy. Bonding them together smoothed out the noise and allowed me to home properly. I'll scope that out as well.
Now that I think about it, I had my spindle driver wired up wrong. From reading the manual on it, I thought that it needed 24v to be applied to the inputs. This was wrong, but I wonder if I accidentally bonded the two 24v power supplies together. Maybe my 24v is noisy. Bonding them together smoothed out the noise and allowed me to home properly. I'll scope that out as well.
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Re: 325 limit on home?
It's not bounce. I did have one or two noisy trips, but most were clean. I have long arm limit switches on my x and y axis. Reset distance is long and appears to be too long. The machine will hit the limit switch, then backtrack waiting for the limit switch to reset. Centroid throughs this error before that can happen. My X axis has the stupid little micro switches and that homes fine.
Is there a way to increase this reset travel distance? Or is that dependent on the marker coming in from my sigma II drive encoders?
Is there a way to increase this reset travel distance? Or is that dependent on the marker coming in from my sigma II drive encoders?
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- Location: Mesa, AZ
Re: 325 limit on home?
You should change to more appropriate short travel switches.610Garage wrote: ↑Mon May 10, 2021 10:13 am It's not bounce. I did have one or two noisy trips, but most were clean. I have long arm limit switches on my x and y axis. Reset distance is long and appears to be too long. The machine will hit the limit switch, then backtrack waiting for the limit switch to reset. Centroid throughs this error before that can happen. My X axis has the stupid little micro switches and that homes fine.
Is there a way to increase this reset travel distance? Or is that dependent on the marker coming in from my sigma II drive encoders?
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
We can't "SEE" what you see...
Mesa, AZ
Re: 325 limit on home?
Yes. New in CNC12 version 4.20, you can set a distance in Machine Parameter 180. This will be the maximum distance to back off, after the switch trips, while waiting for the switch to clear again.Is there a way to increase this reset travel distance? Or is that dependent on the marker coming in from my sigma II drive encoders?
That said, Marty is right that you would be better off changing to a different switch design with shorter travel.
This is not related to the index pulse signal coming from the drives. CNC12 does not begin watching for the index pulse until after the limit switch closes again.
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Re: 325 limit on home?
Yea.... *sigh* yea... They did not think about limit switches with this mill when they designed it. At least, that's what it seems. I went with these cuase they seemed like they would fit the best. I didn't realize how much stroke the limit switch would have until I had them installed. I figured it would lead to some issues. I was jsut hoping to have the machine somewhat running before I had to fix them for the 3rd time.martyscncgarage wrote: ↑Mon May 10, 2021 12:11 pmYou should change to more appropriate short travel switches.610Garage wrote: ↑Mon May 10, 2021 10:13 am It's not bounce. I did have one or two noisy trips, but most were clean. I have long arm limit switches on my x and y axis. Reset distance is long and appears to be too long. The machine will hit the limit switch, then backtrack waiting for the limit switch to reset. Centroid throughs this error before that can happen. My X axis has the stupid little micro switches and that homes fine.
Is there a way to increase this reset travel distance? Or is that dependent on the marker coming in from my sigma II drive encoders?
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Re: 325 limit on home?
Thanks, I tried that. It tripped and cleared the limit switch, but now it's throwing a "457 Unable to find home" which I am guessing is do to the limit switch accuracy?cncsnw wrote: ↑Mon May 10, 2021 12:26 pmYes. New in CNC12 version 4.20, you can set a distance in Machine Parameter 180. This will be the maximum distance to back off, after the switch trips, while waiting for the switch to clear again.Is there a way to increase this reset travel distance? Or is that dependent on the marker coming in from my sigma II drive encoders?
That said, Marty is right that you would be better off changing to a different switch design with shorter travel.
This is not related to the index pulse signal coming from the drives. CNC12 does not begin watching for the index pulse until after the limit switch closes again.
I'm looking at new limit switches. Just curious, can oak handle 2 limits and a separate home? So 3 limits per axis?
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Re: 325 limit on home?
Post pictures of these switches on the machine, or the make and model. We can make better suggestions. Remember, we can not "See" what you "See"
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
We can't "SEE" what you see...
Mesa, AZ
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- Posts: 24
- Joined: Sun Mar 28, 2021 12:06 am
- Acorn CNC Controller: No
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- DC3IOB: No
- CNC12: Yes
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Re: 325 limit on home?
OK, I was just assuming they were crap. The small white limit switch is oem. The one pic is from a video I made of the Y axis home limit switch. It probably gives you the best idea of how these limit switches are working. This is a Milltronics Vm16.
https://www.automationdirect.com/adc/sh ... stp100da-l
I was thinking of using these as home switches. I would need to relocate them. Z is easy, but Y might be an issue. I was going to look over it today to see if I could use them. I didn't use them before because a hard crash would wipe them out, but then again, does that really matter? Mostly thinking out loud now.
https://www.automationdirect.com/adc/sh ... stp100da-l
I was thinking of using these as home switches. I would need to relocate them. Z is easy, but Y might be an issue. I was going to look over it today to see if I could use them. I didn't use them before because a hard crash would wipe them out, but then again, does that really matter? Mostly thinking out loud now.