Posts made by SanderLPFRG

@jay_s_uk yeahh I tried that already, but selective probing with scanning-type probe still tries to, youknow, scan.

Guess the only possibility is to enable the possibility to define a type1 probe on a CANboard

@jay_s_uk Hi, thanks for the reply
You mean setting the Probe type to P0? can I then still do a G30 probe with the load cell?

Hi,

I can now only configure our analogue-in loadcell probe as a SZP, which reads the signal correctly, and G30 functions well, but when doing a G29, it tries to scan the bed, resulting in a nozzle that scrapes the bed.

Until I figure out the firmware, I want to enable a simple mesh probe manually, which I want to do with;

M561                    ; clear any bed transform

; If the printer hasn't been homed, home it
if !move.axes[0].homed || !move.axes[1].homed || !move.axes[2].homed
  G28

; Probe the bed and do auto calibration
G1 X{move.axes[0].min} Y{move.axes[1].min}  U{move.axes[3].max} Z10 F12000   ; go to neutral position

;Start probing
G30 P0 X25 Y25 Z-99999
G30 P1 X299.5 Y25 Z-99999
G30 P2 X574 Y25 Z-99999
G30 P3 X25 Y250 Z-99999
G30 P4 X299.5 Y250 Z-99999
G30 P5 X574 Y250 Z-99999
G30 P6 X25 Y475 Z-99999
G30 P7 X299.5 Y475 Z-99999
G30 P8 X574 Y475 Z-99999
G29 S3 P"usual.csv" ; save probed points to "usual.csv"

I wonder if such thing is even possible, any tips?

@dc42 is it okay if I try to enable this functionality in a branch via github? If I manage I will make a pull request for you to integrate it into the main branches.

Lot to learn for myself, but I like a challenge.

@SanderLPFRG Got it working, version mismatch.

@dc42 I just tried to build with the latest master branch of the libtinyusb from here; https://github.com/Duet3D/LibTinyusb

I also tried the 3.6.0 beta2 release, which is the same as the rrf sourcecode I am trying to build

still did not work, same error

@dc42 please note that the tusb.h file is actually present

@dc42 said in Other analog Scanning Z Probes?:

Yeahh the biggest issue is that I do not want the loadcell configured as a scanning-type probe, but as a normal analog probe, which is prohibited for CANboards. so I am leaning to version 2.

I am trying to build new firmware for the 6HC (to remove the error it raises when remote Z probe type is not 8, 9 or 11) but I am getting building errors regarding the CoreN2G...

"../src/TinyUsbInterface.cpp:28:10: fatal error: tusb.h: No such file or directory"

@droftarts I see.

I get why it would be a possible issue with latency but for our use we need to be able to define it as such.
We found in the source code where it defines the probe and throws an error, but we would like some advice on if just removing the error gives us a solution

@droftarts Old topic, but I have another general analogue output probe (loadcell with op-amp structure and amplification with custom canBUS board)

I can configure and measure using the scanning Z probe (11) definition, but a load cell is unsuitable for a "scanning" measurement. It is however not possible to define it as a P1 probe on a canbus toolboard.

May I ask why this decision was made, and where in the firmware I could look to make it possible?

@gloomyandy could work, but the issue here is that if I just move the drive mapping to set Z=V and V=Z. the axis could move out of physical bounds, which damages the machine.

Will test tho, but I think it does add value to RRF in the future, 'just' add a parameter to G30 command.

Another thought, could a G38.2 with V target position work? I don't fully get what the target position does here.

@SanderLPFRG @gloomyandy or @dc42? any possibilities or workarounds??

@oliof yeah load cells are susceptible to temperature differences (see the graph above) but you can correlate that enough to avoid issues.

@Notepad Thanks! it has been a long journey for us but generally, we found;

• Digital versions of chips (fe HX711 / HX717) offer (for us) a too low sampling rate (max 320Hz) so you would need to probe slowly, or it may be too inaccurate.
• Analog versions are susceptible to noise, especially within a 3D printer with all the active stepper motors. The only way we got it working is by making a custom CANbus PCB that sits only 7cm from the load cell and there filters and amplifies the analogue signal. We then read it out as an analogue probe in Duet

@Notepad works really well, thanks!

Got good results too, and plotted them in graphs! which shows a fun correlation of the temperature drift of our probe!

Thanks for the script! Appreciate it

Hi all,

We have made a 3D printer with 2 micro-Z printhead axes (V and W), which move the IDEX printheads up and down 14mm to level 2 different tool types and automatically adjust/calibrate the printhead Z-offset.

We first got this system working with a microswitch type probe, which we, in a macro, temporarily reconfigured as an endstop for axis V/W, which we then "homed" towards the printed until triggered. When done for both tools, this calibrated the Z-offset automatically.

Now, however, we moved over to a loadcell probe (analog readout via configuring as scanning Z-probe, amplified and filtered with custom CAN-communicated PCB) which we cannot configure as an endstop to home towards.

My question is;
Is it possible to do a G30 S-1 probe (just probe and stop) with a probe number defined (K0/K1), but move axis V or W instead of the Z-axis

note;
running 3.6.0 beta-2

@Notepad @droftarts ,

My goal is to test a shitload of probes, and see how much it starts to deviate after thousands. Your script might actually work, let me test

Hi all,

we are trying to test the reliability of our new loadcell probing system to see if it lasts 10 years.

it equals to a load of probes (213.000) which I plan to test in 4 stages (53.250 per test)

I wanted to test it with a loop;

while iterations<53250
    G30 P{iterations} Z-9999
;endif
G30 P53250 Z-9999 S-1

But quite quickly I get the error "Error: G30: Z probe point index out of range"

Is there a different way to do these long tests?

@droftarts Hi,

Get it, so I can only connect a digital sensor to the expansion boards??

May I ask why this limitation is in place? and is there a way to hack myself around it in firmware? Like can I trick the firmware into thinking there is a SZP connected? that seems to put out analog signal as well.

@droftarts

Thanks for the quick reply.

The loadcell circuit is now implemented to a custom Devboard we made, and therefore hardwired to a "Thermistor input". (based of of this previous topic; https://forum.duet3d.com/post/262561) We will see if we can rewire it to an IO input.

Can we then configure the P1 analog sensor from an expansion board??

As for the files; sure, we got a lot of help from the community so it would be nice to give something back. I cannot give the schematic tho, since that is still in development.
Basically, we self-developed the wheatstone-bridge load cell sensor with the 4-wire pinout (EXC+, EXC-, Sig- and Sig+). Then we wired these to an INA818 op-amp to amplify the signal significantly and used some diodes to limit the output voltage to 80mV and 1.92V to protect the ADC input on the chip. Amplification is set with a resistor