Z-Probe?

Chriss

Hi *,

I have the feeling that the selection of the right z-probe is an endless story in the 3d printing world. There is a wide variation of z-probes in my shelf and I was never fully happy with any of them. Starting from BL_Touch, DC42 IR-Probe, Inductive prbes like Vinda/Pinda etc.
My Voron has a Klicky at the moment and even that varies in the z-offset now and than.
The beacon is not an option on a Duet board. And the Voron Tap has many other problems which prevents me of using it.

And the "new" scanning probe seems to have issues with the temperature too. Or am I wrong here?

I do not change nozzles frequently but surfaces, so the probe should be as surface agnostic as possible but should not have problems with temperatures or, at least, a very well working temp compensation.

Any other ideas? Any other probe which is worth to give it a try? Or is the z-scanning probe "the solution".

Cheers, Chriss

dc42

@Chriss if you want your probe to be surface agnostic then the best option currently is some sort of contact probe. Make sure it uses a really good switch, configure it as type 8 not type 5, and don't probe too fast.

Chriss

@dc42

I probe with the euclid the last tiem with this settings:

set global.probe_settingsH=0.5
set global.probe_settingsA=30
M558 P8 H{global.probe_settingsH} A{global.probe_settingsA} S0.003 F700:120 C"^121.io2.in" T8000 B0 R0

I have the feeling that it is getting worth over the print times. It seems to me that the thermal expansion of the toolhead and the micro switch etc come into play here. Not sure if there is any way to tackle that. But it is a nightmare to be honest. I print a lot of small parts with one of my printer so I run into that problem over and over again.

Cheers, Chriss

moth4017

@Chriss how much variation are you seeing and what Temperature is your chamber

Chriss

@moth4017

Hard to tell, but I would say that I need to babystep down up to 0.06mm. It is so bad that the button layer has real gabs. The chamber is up to 50-55°C.

Cheers, Chriss

moth4017

@Chriss 0.06 would be normal for most printers I've worked with you can either do your homing when the printer temperature has become stable this could be 15 to 30 minutes depending on the printer all just make your first layer thicker to compensate. If it's always the same amount of offset just add it to your config file.

Chriss

@moth4017

And here does the problem starts. The first 2-3 prints (10min ruffly) are OK, it starts afterwards to get messy and I need to readjust. I have the hope to find a better way for probing than waiting 30 minutes to prewarm a printer which prints 10 minutes only in the worst case scenario.

This z-Probe issue seems to be an endless story I fight with since 5+ years. Still have the hope to find a better way to get rid of that thermal issue.

Cheers, Chriss

moth4017

@Chriss you will need to find what is moving, if you can get hold of a dial gauge you can use that to see what is moving .

Chriss

@moth4017 I think that is not sooo easy here. The dial gauge will be infected by the rise of the temperature too. Maybe with a laser which crosses the chamber.... I have to think a bit more about it.

moth4017

@Chriss laser wont be accurate enough . most dial gauges are ok up to 40C , you just need to use the same reference point on the frame to see what moves
the most .

moth4017

@Chriss do you have a carbon fiber x axis , if so do some checks of the z offset in the middle and at one end , as depending on the quality of the carbon tube then do move

Chriss

@moth4017 Nope, it is still alu extrusion. And I z home always at the same place, so this should not be the problem. I strongly believe that the change of the offset come from the thermal expansion if the switch itself and all other parts which connect the upper part of the hotend and the switch.
The hotend expands too but I'm sure that the hotend and the plastic does not have the same expansion per K.