Induction Z Probe Tuning issue.
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@sozkan said in Induction Z Probe Tuning issue.:
Z offset is equal to the head. When the sensor triggered at the zero height of the nozzle.
very unlikely, even with the piezo or the duet smart effector where the actual probe is the nozzle its not 0.
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@Veti said in Induction Z Probe Tuning issue.:
@sozkan said in Induction Z Probe Tuning issue.:
Z offset is equal to the head. When the sensor triggered at the zero height of the nozzle.
very unlikely, even with the piezo or the duet smart effector where the actual probe is the nozzle its not 0.
I understand that. The sensor's physical distance 4 mm above the nozzle height. But sensor trigger at zero of the nozzle height. By the way, it is a huge machine and I may need to put 1 mm clearance to the bed not to crush during vibration. Because the Extrusion nozzle 2.5 mm. it is probably acceptable tolerance.
Do you have any suggested numbers for the Z?
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you have to measure it, like its describe in the linked document
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@Veti Thank you. I will follow the instruction.
But in my case paper seems very thin. I assume paper 0.1 mm thick, and on my scale, I thought a 1 mm board instead of a paper. Head and axis weighs about 18 kg and causing a small vibration during the move.
What do you think? -
the reason why i also want you to run this is because it also test if your probe is working
i dont know if at the size of your printer 1mm is making much of a difference. what is the nozzle size?
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@Veti nozzle size 2.5 mm.
The sensor seems working. Because when I put metal nearby the edge of the sensor, the light on the sensor switch on, and Duet web interface also probe indication changing by 0 to 1000 or wiseverse. -
@sozkan said in Induction Z Probe Tuning issue.:
The sensor seems working.
i want to establish that the g30 command is working
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This is how I do it: get the nozzle height set manually the paper method and m665 don't worry about the probe yet. Being safe i send a G0 z10 then jog the z height down to the paper, then home and do it again from like Z1 to verify Z0 is just touching the paper. If it doesn't I need to start looking for why my movement isn't consistent.
After your sure your movement is stable, make sure your probe is triggered at Z0, if it is I home and send it down to like 5-10mm then run a G30 S-1, this will tell me the height my probe triggers at from the point I wanted as my Z0 height. Send it back up 5 mm or so and do the g30 S-1 again. These will give you indication on how precise you probe and movement are. NOTE: most inductive probes under $60 typically trigger at a rate of 500Hz, so your probe trigger height will vary plus or minus the distance it travels in 1/500 of a second in that case and it can easily be .1 mm
Plug that probe trigger height into G31 and you should have a good trigger height to auto calibrate from.
Other techniques I've used, a metal cylinder centered with the nozzle will let me jog the effector around to find the center which the probe triggers ( ex: move the probe in from the left until it triggers, then from the right and split the difference is my x offset (invert before you send it in g31) This also let's you assess the shape of the field that triggers from the probe which is really more of a peanut shape than a circle and any tilt in your probe thats different from your hotend will show in your auto calibration. For me I also have to rotate the inductive probe so the response shape to be symmetrical in the x and y because it drives me crazy knowing that invisible field isn't lined up lol.
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ok so g30 is working?
can you measure the height using g30 within 5 mm?
if that is also accurate then increase the move height after each trigger
M558 H30to something big like
M558 H150
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I don't use high dive heights on my probe since I have M558 set to like F60, so big dives would be painfully slow. I use that value since it gives me repeatability in the (off the top of my head, it's been awhile) +/- .003 mm range with a 1Khz switching frequency probe (basically within a microstep
). If my calibrations aren't under .020 (typically .014 because I got tired of fiddling with bits to hit .009) I know I need to check the machine for loose bits. Here's my config settings to compare and my probe is an IFM IE5390 MSRP $93 ($30 off of ebay)M558 P5 C"e1stop" H3 F60 T3000
G31 K0 P10 G31 X24.4 Y-1.1 Z0.546I also found that large dive heights at slow speeds would cover up issues I'd need to address like skipped steps in fast movements, so I just use travel commands to go up quickly then back down to a reasonable probe distance, maybe even a little to the left and right to check for backlash.
Also you typically can't use the advertised trigger distance for your inductive probes most of the time, which is the response distance to ferrous metals such as steel. Aluminum will trigger at about 30-45% of that distance unless it's an all-metal/ K-factor (correction factor) probe. note: The larger the sensing distance, the larger the variation in the drift of the trigger distance, so it's best to pick a probe with the smallest trigger distance while giving you a safe clearance above nozzle height.
If you have a cylinder type probe that you can easily adjust the height of the probe like mine, I move the nozzle to the height above your bed you want the probe to trigger at and then adjust the probe height until it just triggers. Keep in mind that the trigger distance in aluminum changes significantly (relative to bed leveling) between a cold bed and a hot bed. It's not THAT bad, a few baby steps should compensate for it when you go to print, but if you're going through the effort to set everything up right why not account for it.
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this is just for the inital setup to get calibration to run once as you have not achieved this yet.
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@Veti said in Induction Z Probe Tuning issue.:
@sozkan said in Induction Z Probe Tuning issue.:
The sensor seems working.
I want to establish that the g30 command is working
Thanks. It works.
G30 S-1 Stopped at height 0.101 mmI probably need a proper bed calibration command set.
From the center of the bed to outside radios difference around 3 cm. The Head is moving on a parabolic curve on the X-Y plane. IT is not a moving plane.
The sensor works, but still needs bed calibration I think. So what should be the next?
