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Re: BLTouch Auto Leveling Sensor

PostPosted: Sat Feb 03, 2018 3:38 am
by stottsjr
Sounds like it's doing what it's supposed to be doing. Can you capture a video and post it somewhere?

Re: BLTouch Auto Leveling Sensor

PostPosted: Sat Feb 03, 2018 12:41 pm
by sonra
Hi
I found the problem .The sensor tip when in push position ( down ) was a little above the extruder , so the table when try to go to home position crushed into the extruder and not the sensor . Now i put spacer so the sensor tip is below the extruder and G28 and G29 do the job

Z PROBE_OFFSET_FROM EXTRUDER

PostPosted: Thu Feb 08, 2018 8:16 pm
by sonra
Hi ,
I have the M2 with v4 extruder ,use Samplify as control software . I installed the BLTouch sensor and one of my of setting I am not sure about is the
Z PROBE_OFFSET_FROM EXTRUDER in the configuration.h ,what is the best way to define it and how it change or not the setting of Globel G code Offset in the Simplify process setting .
regards Doron

Re: BLTouch Auto Leveling Sensor

PostPosted: Fri Feb 09, 2018 3:56 am
by stottsjr
It's trial and error. All printers will be different even ones of the same model.

M851 will be your friend in figuring it out and you'll use the "Communication" tab in the "Machine Control Panel" in Simplify3D.

You'll basically set an offset with M851 like:
M851 Z-1.5 // These numbers are in MM and you can go 2 significant digits i.e -1.55

If you're running into the bed then you're too low and you'll have to add positive numbers, if you to high then you add negative numbers.

I find that you should do a home all or a G28 after each setting of the M851 to verify the new setting and repeat until you get the correct one for your printer. Once you figure out your number then you change it in the firmware and upload it.

Re: BLTouch Auto Leveling Sensor

PostPosted: Fri Feb 09, 2018 1:31 pm
by ednisley
stottsjr wrote:It's trial and error [...] M851 will be your friend


Having just replaced the hot end thermistor, I tried setting the new nozzle offset with M851 and found it had no effect, at least with Marlin 1.1-RC5, a two-year-old version supposedly supporting M851. Perhaps M851 only participates in complex Z probing, but the G-Code doc isn't forthcoming.

M206 worked, after some protracted headscratching, with M500 to store the final offset value:

Image

Bottom line: trial-and-error also applies to discovering which G-Code works with the firmware in your printer!

Re: BLTouch Auto Leveling Sensor

PostPosted: Fri Feb 09, 2018 2:12 pm
by sonra
Hi
May be i don't understand what I suppose to happen but i try to describe what i see
1) I sent a M280 P0 S10 command to drop the tip down . the tip is about 2 mm below the extruder
2) I send M851 with Z negative number
3) I recive a message "echo:Z Offset ok"
2) I send a G28 command
The bed hit the tip and the extruder is about the 1.5 mm above the bed .I tried to change the number to -3 or -0.1 but got the some result
What am I doing wrong ??
Doron

Re: BLTouch Auto Leveling Sensor

PostPosted: Fri Feb 09, 2018 11:43 pm
by stottsjr
Yeah, I'm using Marlin 1.1.8 since it has more features and better options for bed leveling.

Your switch looks like a limit switch (So it's probably not sending the correct signals.) and not a BLTouch and this might be the cause of your issues.
You can see a true BLTouch in this thread.
viewtopic.php?f=10&t=6418

Re: BLTouch Auto Leveling Sensor

PostPosted: Sat Feb 10, 2018 12:11 am
by sonra
I am using the BLTOUCH . Do i have to adjust the Z offset number only when I try to print and if the print is not OK or there is other way to do it ?
I mean can I enter as default -1.55 and adjust it according print results or is any way to do it ?

Re: BLTouch Auto Leveling Sensor

PostPosted: Sat Feb 10, 2018 3:04 pm
by ednisley
stottsjr wrote:Your switch looks like a limit switch


Aye, because the BLTouch solves a problem I don't have.

Point was: maybe Doron's problem comes from a Marlin firmware version mismatch, where the proper commands don't do quite what's expected.

Re: BLTouch Auto Leveling Sensor

PostPosted: Wed Feb 14, 2018 9:38 pm
by sprior
Ed, since you mentioned you aren't using a BLTouch (which I installed this last weekend in my M2) are you doing Z sensing but not bed level compensation with that switch? It looks like maybe you sense Z with the nozzle off the edge of the bed, but the switch over it?