indraastra
08-23-2013, 04:34 PM
(edit - Sorry, didn't mean to post this to the Shopbot Desktop forum, but there doesn't seem to be one for the PRS Standard)
We've been plagued by various Z zeroing problems but in the last couple of months, but recently a new strain has developed on our Shopbot PRS Standard 96x48.
Here is what happens during the Z zeroing routine (C2) about 25% of the time:
1. the first plunge happens
2. the bit makes contact with the plate
3. Z is set to the thickness of the plate (.120")
4. the router moves up to a safe Z height (1")
5. the second plunge happens
6. the bit stops JUST before making contact or JUST after touching on the plate, but the Shopbot software says "Zeroing failed"!
Sometimes the green light above input #1 is on indicating contact, and sometimes it is off.
Based on the code, one of two things should happen first during the second plunge:
1. The bit reaches its target depth (-.120", or negative the thickness of plate)
2. The plate makes contact with the bit
Neither one of these happens!! If the target depth was reached, the bit would have driven into the plate AND the bed. If the plate had made contact, then execution wouldn't have reached the failure condition in the G-code. Some mysterious thing seems to detect that contact either has been made, or that the Z depth has reached where it was on the first plunge, because it is ALWAYS on the second plunge, and ALWAYS stops just short of the plate yet reports a failure.
It isn't consistent, but it is frequent enough to annoy the heck out of everyone who uses the bot. It seems to be related to the firmware/hardware/software and not any kind of grounding issues, like with other failures we've had, but I could be wrong.
I set the second Z zero plunge rate to be 1/2 the original value, and in the few times I've tried it since, the problem didn't happen at all. I don't know what that would have solved the problem. I've seen some similar experiences shared on the forum, and at least one person reverted to an older ZZero.sbp without any further issue. Has anyone else experienced this?
Thanks!
Vishal
We've been plagued by various Z zeroing problems but in the last couple of months, but recently a new strain has developed on our Shopbot PRS Standard 96x48.
Here is what happens during the Z zeroing routine (C2) about 25% of the time:
1. the first plunge happens
2. the bit makes contact with the plate
3. Z is set to the thickness of the plate (.120")
4. the router moves up to a safe Z height (1")
5. the second plunge happens
6. the bit stops JUST before making contact or JUST after touching on the plate, but the Shopbot software says "Zeroing failed"!
Sometimes the green light above input #1 is on indicating contact, and sometimes it is off.
Based on the code, one of two things should happen first during the second plunge:
1. The bit reaches its target depth (-.120", or negative the thickness of plate)
2. The plate makes contact with the bit
Neither one of these happens!! If the target depth was reached, the bit would have driven into the plate AND the bed. If the plate had made contact, then execution wouldn't have reached the failure condition in the G-code. Some mysterious thing seems to detect that contact either has been made, or that the Z depth has reached where it was on the first plunge, because it is ALWAYS on the second plunge, and ALWAYS stops just short of the plate yet reports a failure.
It isn't consistent, but it is frequent enough to annoy the heck out of everyone who uses the bot. It seems to be related to the firmware/hardware/software and not any kind of grounding issues, like with other failures we've had, but I could be wrong.
I set the second Z zero plunge rate to be 1/2 the original value, and in the few times I've tried it since, the problem didn't happen at all. I don't know what that would have solved the problem. I've seen some similar experiences shared on the forum, and at least one person reverted to an older ZZero.sbp without any further issue. Has anyone else experienced this?
Thanks!
Vishal