Auto-leveling using an Inductive Sensor

[originalt80]

So am I missing something? Where is the circuitry and motors that levels the build plate?

with this sensor it uses Z axis to compensate for slight changes in the bed.. someone more knowledgeable can explain it better

[ejcruz]

No reason to be sorry. without your help and suggestions i would still be sitting here scratching my head staring at this single page of the specs for the bltouch sensor wondering if id ever understand it. lol your help is greatly appreciated cant wait to see how this all works out.

one thing i was wondering about is a way to mount the sensor and a good location so that its close enough to the nozzles and not cause any issues with clearance around it. i searched all over for a printable bltouch mount for the FFCP but couldnt find one anywhere. i did however come up with my own mount for the sensor and a good location for it..(i think it is a good place at least) i will take a few photos of how i have it mounted and maybe u can let me know what ya think on it.. note that i have not yet set the height of the sensor. and the sensor needle is about 1.5 inches away from the first nozzle head.. is that to far away? thanks

stupid thing isnt uploading the pics so here r my dropbox links to the pics sorry for that.
https://www.dropbox.com/sc/4lk96bafw...vLNfVnyFN43v7a
https://www.dropbox.com/sc/qs260utg7...Nqy2HnhDzkiTha
https://www.dropbox.com/sc/hytme0noh...Xn-vkQ-OWxHSSa

The info I got from BLTouch recommend to position the sensor needle at least 15mm from the nozzle, that does not mean 1.5 inches (38.1mm) will not work, most likely not as effective, also the base of the sensor body needs to be 8.3mm (+/- 0.2mm) above the nozzle tip. I suggest you should make or print a block that is 8.3mm in height to be used to set the sensor height.

My plan is to remove the left extruder (I normally only use the right extruder) this will make space to mount the sensor closer to the right extruder nozzle. I'm planning to design the sensor mount so it's easy to install and uninstall should I ever need to use the left extruder.

[originalt80]

oh yeah duh i didnt even think to look at that info for the 15mm distance lol.. but yes i know about the 8.3mm abpove nozzle tip and i have already printed the block to use for setting the height i just never did it yet cause i didnt even know if it was a good place to put the sensor or not.. im a rookie at this bare with me please but yeah since i am aa newbie to 3d printing i havent even began to learn about printing with both extruders together so i just been using the left PLA printing and the left for ABS printing so really your plan for removing the 2nd is about the best way to go about it.. i will just follow how you install it.. if that is ok with you of course?? maybe once u get your mount design completed u could possibly share the design. that would be wonderful.. thanks again for all your help

[ejcruz]

with this sensor it uses Z axis to compensate for slight changes in the bed.. someone more knowledgeable can explain it better

My understanding is that the firmware will control the adjustment using the Z-Axis. Before actually starting the print a probing sequence is activated to measure the Z-Axis height on each of the three leveling points, if any of these measurements are outside of the specified height (user defined) the printer will stop and display an error message and will not print, however if the height measurement is within the specified height, the firmware will store these new height measurement in memory and compensate accordingly during the print - this means when you set the layer height at 0.20mm and the sensor probing measures the nozzle height at 0.30mm, and 0.30mm is within the specified height, then the firmware will compensate by lowering the Z Axis 0.10mm during printing. NB. once the probing is completed, the sensor is not used or accessed until you start a new print - the firmware will automatically disable auto-levelling on completion of the print.

As for the BLTouch sensor, it has two sets of wiring, a three wire set which needs to be connected to any servo connection points on FFCP board, and a two wire set which needs to be connected to the Z-MIN connection point because this will allow you to use G_CODE like M131 A to probe point 1, M131 B probe point 2, M132 AB activate auto-leveling, M280 P0 S10 push the sensor pin down. So when you send the G_CODE M280 P0 S10, the firmware sends that code to Z-MIN socket, and because the two wire set of the BLTouch is connected to this socket, the internal program of BLTouch will activate the sensor solenoid to push the sensor pin down.

As mentioned in the first post of this thread you must run Sailfish V7.7 release 4.7, when I checked my FFCP I was running V7.7 release 4.2, so I upgraded my firmware.

Hope this helps

[jfkansas]

Ya, not really. I just don't get the benefit. lol You can't call it auto leveling if it is just measuring is the problem I have with it.

Seems like a lot of work to not really gain any functionality over the z limit switch and a little manual knob turning.

[originalt80]

Ya, not really. I just don't get the benefit. lol You can't call it auto leveling if it is just measuring is the problem I have with it.

Seems like a lot of work to not really gain any functionality over the z limit switch and a little manual knob turning.

well if you have a problem with it then stick with what u do now if that works for you. those of us interested in using the feature will use it.

[jfkansas]

well if you have a problem with it then stick with what u do now if that works for you. those of us interested in using the feature will use it.

Lol, just trying to get what all this work does or does better than a mechanical switch. I'm all for a truly dynamic full auto leveling if it actually does what is says it do.

[ejcruz]

Good news, Flashforge today (27th August) confirm the connection as per the attached image will work.
https://photos.smugmug.com/3D-Printe...ch-FFCP-XL.jpg

Originalt80 you can test by sending the following g-code:
M280 P0 S10 ; sensor pin down
M280 P0 S90 ; sensor pin up

Thank you.

[originalt80]

Good news, Flashforge today (27th August) confirm the connection as per the attached image will work.
https://photos.smugmug.com/3D-Printe...ch-FFCP-XL.jpg

Originalt80 you can test by sending the following g-code:
M280 P0 S10 ; sensor pin down
M280 P0 S90 ; sensor pin up

Thank you.

gladly but can u suggest what software to use for sending the g-code?
i have the following:
ReplicatorG (included with prointer)
Simplify3D
Printrun-Win-Slic3r-03Feb2015 -- Pronterface
arduino-1.6.9-windows
Flashprint

as stated i am a newbie so if u can point me in the direction where i enter the gcodes to send it would help.. this is all new to me sorry. i will gladly test anyway i can

[ejcruz]

You need to connect your PC via USB connection to FFCP, then:
1. run Simplify3D
2. Click on Tools and select Machine Control Panel
3. Normally Simplify3D will automatically connect to FFCP, if not then click on the Connect button
4. Click on the tab Communication
5. In the dialog box next to the Send button (bottom of the page) type the g-codes
6. Click the Send button
You should see the BLTouch pin head go up and down when you send the g-code