SmartEffector DeltaCalibration: Z probe readings not consistent

ignacmc

@jay_s_uk But I f I increase deviation to higher than 0.03 will it still be reliable? I am unable to have a decent 1st layer squished against the ultrabase bed....most of the times I am printing on air

ignacmc

@ignacmc And If I do it in cold conditions....it succeeds in a breeze. Can it be so diferent while hot?

jay_s_uk

@ignacmc the bed is probably slightly warped. I had the same issue with my predator.
It's something you have to live with or try and tighten the mechanical slop. Difficult with vslots though

ignacmc

@jay_s_uk Could you explain me a bit more how to tighten the Mechanical Slop?

jay_s_uk

@ignacmc what sort of rods do you have? have you got the belt tightness correct? are the wheels running smooth with no mechanical play in the carriages? do you have painted rails or anodised rails? how flat does the bed look at 100 degrees (use the height map).

ignacmc

@jay_s_uk Update: I got my config files from a spanish Duet users group on Telegram. The expert from the group (Kkapa) was very kind to send me those...

Seems that he had the following line on bed.g:

M558 F300 A5 S0.003

The default value for S is 0.03, so this is 10 times more strict. Changing it to 0.02 seems to have solved the problem. Now it succeds on the first run while hot!

Regarding your questions:

1 I have a custom rods 440mm long made by me one by one on the same jig. I used MPJET ball links which I can tell you that have absolutely no play: https://mpjet.com/shop/gb/ball-7-mm-dia/1295-ball-link-v1-type-7-mm-dia-m43-short.html.
2. How to know the correct tightness of the belts? I have tightened the thumbnut by hand as much as I could
3. I have checked and as of today there is no play on the wheel...I adjusted them some days ago
4. I would say that they are painted...some day i would like to put some lineal rails there
5. To use height map i would have to use G29....there is a lot of G32 vs G29 controversy (https://hennerley.wordpress.com/2018/01/29/g29-vs-g33/) where some people says that you should't need to use G29 on a delta unless the build or the bed is a complete disaster...I am restraining from that by now...what is you opinion?

dc42

@ignacmc is the nozzle clean when you probe hot? I usually see a little filament oozing from the nozzle after preheating, so I remove it using tweezers before running auto calibration. Sometimes it probes the first point three or four times, buf after that is generally probes each point twice.

You have your tolerance set to 0.003 in M558, which is very tight and almost certainly less than one microstep. So the slightest change will cause multiple probing. If you are using a glass bed, after the indicated temperature is stable it will take several minutes for the glass to stop expanding and the top surface to reach a steady temperature. So consider increasing the tolerance in your M558 command, perhaps to 0.010.

EDIT: I see that you have already increased the tolerance to 0.02, which is also what I use.

ignacmc

@dc42 Yes, Now I don't have any problem with G32. the sensivity was probably a typo of the guy who send me the config.g. Changed to 0.02 and now it runs perfect

apak

@ignacmc indeed it was a typo!!!

ignacmc

@apak Thanks Guru!