Looking for Prusa help or a forum with Prusa expertise

3D Printing
1

First post here… Hello!

I recently purchased two used Prusa i3’s a MK2 and an MK2 upgraded to MK2.5S

The upgraded one does not work and I’m looking for a forum where I can get info on how to fix it. I’m new to 3D printing but I’m an engineer so pretty good at fixing things.

I posted on the Prusa forum, but have had no response.

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I was given a Prusa i3 MK2 upgraded to MK3.5 last summer and went through it and I too had calibration failures when the censor was not getting to the spots on the bed. There was an offset somewhere, sorry it’s been months and I only did it once. The machine is now at a local Middle School so not readily handy for me to look at to jog my memory.

My mk3.5 had the MMU1 on it so I could not upgrade the firmware so even that is going to be different. But I’m pretty sure there is something in one of the calibration options which got the PINDA aligned enough for auto calibration to work.

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Doug,

Much appreciated, every little piece of troubleshooting information helps.

For anyone following along…

One thing I want to know is does the first point in the XYZ calibration occur at the front left target or a fair bit 1.5cm to the left of the target?

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I know that the standard Z bed leveling(before each print) starts at the front left and ends at the back right. I don’t remember what happened when doing the main calibration which includes moving the motors to the top just before they hit the stops at the top.

I do believe they all had to be really close to the circle targets on the base plate.

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I think your right and that is probably the problem, but I can’t be sure. When I figure it out I will update this thread.

Thanks

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6

Finally made some progress…

This printer was upgraded in various ways in the past by the previous owner and the history was lost along the way. It appears that all of the MK2.5 upgrades were applied and I think but not 100% sure they also upgraded to a SuperPinda. It has only three wires so not the four wire as called out in the upgrade procedure.

Being pretty much clueless about the evolution; 2, 2s, 2.5 , I loaded incorrect firmware during debugging and that was the fundamental problem. The moment I used MK2.5 firmware it breezed through the XYZ calibration.

I still have two issues to contend with:

  1. The left hotend fan works but throws an error code during the self test. This appears to be the Noctua or whatever it’s called 3 wire fan, and the PO has the tach signal wired up to the connector adjacent to the end stops(as per the upgrade document), however it seems like the firmware is not actually seeing the pulses.

  2. Live Z adjustment with test pattern leaves a very limited printed test pattern, and to get any printed pattern at all the Z adjust seems excessive -1100 if I recall. I’m going to do a cold pull cleaning problem 2 might just be a partially logged nozzle?

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I do have a I3 mk2s. It has been working for kilometers of filament without issue.
Calibration does start on the front left corner the pinda shoud be pntinng to the “circles” on the bed.
I don’t know if the original pinda will work with metal plates… My bed has “circles” to remove any conductive metal part to avoid false triggering of the pinda.

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Sorry I didn’t see that the calibration was solved !

Regarding the live adjust. It can be quite “high” value. Mine is running (very well) with -0.7mm.

And I do have 7km filament printed ! (66 days)

If you feel that -1100 is too much you can simply move the PINDA 1mm higher and it should solve the offset (should be -.1mm after).
But I do prefer a PINDA floating high rather than a nozzle crashing on the bed !

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