Best posts made by FrankV

@fcwilt

Dear Frederick,

I think I found the problem. I did several test's.
At room temperature my z-offset = 0.95
My bed at 90 degrees celcius my z-offset = 1.27
My hotend at 250 degrees celcius my z-offset = 1.87

The pinda is just behind the hotend so the temperature is influencing the pinda probe up to 1 mm.

The other thing is even at room temp when I do automatic bed level the same point is getting a compensation of -0.1.

So my conclusion is. Temperature is influencing the probe to much. I tried the temp sensor of the pinda to get corrected for temp. But I don't find how it's calculated and how that algorithm works and if it solves my problem. I ordered a super pinda. Hope it solves the temp issue. I got a bl touch laying around so maybe give that one a try. I never imagine temp is influencing almost 1 mm.

@fcwilt ;
Axis Limits
M208 X0 Y0 Z0 S1 ; set axis minima
M208 X204 Y210 Z238 S0 ; set axis maxima

G31 P500 X0 Y-23 Z1.558 ; set Z probe trigger value, offset and trigger height

@danal thanks this was of great help also for my Duet3. I am a little visual minded so draw this to make it clear for me. Maybe of help to some others too.

@fcwilt

Frederick i think i add these lines. I have to check the C factor with the probe temp sensor. First without compenation and then with compensation and see what the result is.

;M308 S2 P"temp2" A"Pinda" Y"thermistor" T100000 B3950 ; temperature of PINDA2
;G31 P500 X0 Y-24 Z0.95 S21 H2 C0.02 ; C' (temperature coefficient of Z parameter in mm/°C, default zero

@fcwilt Thanks for your help

@fcwilt

Frederick,

This is the graph produced by the Z- probe thermistor and my measurements of the Z offset by G30 S-1 at specific temperatures. So 50 degrees is 1mm extra z-offset this makes the C in the G31 temperature coefficient of Z parameter in mm/°C 0.02 although it's not lineair.

I am adding in config.g:
M308 S2 P"temp2" A"Pinda" Y"thermistor" T100000 B3950 ; temperature of PINDA2
G31 P500 X0 Y-24 Z0.95 S21 H2 C0.02 ; C' (temperature coefficient of Z parameter in mm/°C, default zero

Tried this but it's not leading to higher the trigger distance when the probe is 50 degrees hotter. So this is not working. My superpinda just arrived wich seems to be temperature resistent. Let's try because this is not leading to consistent z-offset in my case.

I changed in config.g the C to T because of Firmware 3.3 in my machine and now it's working:
M308 S2 P"temp2" A"Pinda" Y"thermistor" T100000 B3950 ; temperature of PINDA2
G31 P500 X0 Y-24 Z0.95 S21 H2 T0.02 ; T' (temperature coefficient of Z parameter in mm/°C, default zero

Still going to test the superpinda, see if it works better without compensation.

A little status update from my part. Today I installed the superPinda probe. This probe has no need for temperature compensation like the Pinda V2. It works great and keeps logic more simple to calculate the Z-offsets. Also there is less difference when I probe again and again. So I can advise this superPinda also sold as upgrade from Prusa. You can buy it better from them because it's much cheaper as the orginal manufacturer price from Pepperl-fuchs (superPINDA)
Inductive sensor NBN2,5-8GM35-E1L-Y. I attached the datasheet if anyone is interested. It's rated till 80degrees celcius. I heated it till 110 with no deviation.

Brown is 5V
Blue is GND
Black is signal

An easy drop in to one of the endstop io's when you remove the wings from the connector.

SuperPrinda-datasheet_70134664_eng.pdf

In noticed even deviation of 1.04 mm at 80 degrees celcius.