Factory assembled Core One+: Printer decalibrates during print ?  

RE: Factory assembled Core One+: Printer decalibrates during print ?

If you zip the file you can attach the zip to your post.

RE: Factory assembled Core One+: Printer decalibrates during print ?

Enclosed all 4 Files including the .3mf as well as a screenshot of the .3mf

Thanks for responding. Help is really appreciated ...DrillBitHolder

RE: Factory assembled Core One+: Printer decalibrates during print ?

@hyiger has a good troubleshooting collection here- https://forum.prusa3d.com/forum/prusa-core-one-general-discussion-announcements-and-releases/core-one-troubleshooting-guide/#post-784390
Before doing anything, I'd be sure to do the gantry alignment and belt calibration, then go through each and every calibration so they're all checked with a green check. I'd probably check the belt calibration again after that but not adjust it unless it was significantly off. Use your ears and note if anything seems unsmooth during the process.
I didn't see any problem slicing the .3fm file and it looked like it should print fine, though it's larger than most of the things I print. People do seem to have more trouble with things that fill the bed due to lifting. Then you lose steps and have layer shifts, and it all goes downhill from there. What plate are you using?

RE: Factory assembled Core One+: Printer decalibrates during print ?

I wouldn't expect it on a factory assembled printer, but if there were a loose motor pulley that would certainly shift things. Somebody should know how to directly check that, but I'd start by having the printer on, so the motors are locked up, then try moving the head back and forth and to and fro, feeling for any jumping or backlash. Sometimes people get through the calibration, but it's "iffy". I'd consider the printer solid if you can go through all the calibration steps 3-5 times, with an easy green check for all on every pass, and without the belt frequency changing significantly, say more than 2 Hz. What does the printer sound like? I've tried recording it, but the fan noise seems to drown out the sounds I'm really listening for.

RE: Factory assembled Core One+: Printer decalibrates during print ?

I will try self-test and calibration again tomorrow. The plate I use is "smooth PEI sheet". As far as I could see the model was not shifting at all on the plate and when separating, I had to bend the plate as is described. I have bought a satin sheet in addition - maybe worth while testing this as well. I guess I will start with a very simple model tomorrow (something being printed within minutes ...) - then I'll see.

Thanks a lot already for the info.

RE: Factory assembled Core One+: Printer decalibrates during print ?

Addon: I think I heard the nozzle touch the right wall when printing (same happening during the test - I thought that may be used for sensing the right wall). Unfortunately I have no experience what the calibration test should exactly do an what not). Anyway: tomorrow with further tests ...

RE:

Now video of decalibration:

I have done more calibration and testing, this time on one of the "official" download example (see example drillbit_official). Same effect of decalibration and wrong position.

I have drawn a video this time: in the first seconds correct positioning of bed (video 1.mp4  ). After about 2 minutes the nozzle bangs at the corner an from then on gets a wrong postition (the model should be created on the middle of the bed, not at the corner, on top of the waste

see Video 2.mp4  https://storage.googleapis.com/prusa3d-content-prod-14e8-wordpress-forum-prod/2026/03/0f6057ee-2.mp4

Since I have no idea what is wrong there, help is really appreciated.

RE:

Thanks for sharing the video. To others who want to watch it: You will need to remove the trailing period from the link. I also had to save the video locally any play it in Windows media player since my browser played only the audio, but that may be specific to my browser.

It looks like as soon as the printer has to execute a fast movement (moving from the fat priming trace to the actual print position), it misses does not execute that movement properly and hence loses its XY position. Since the sound from the stepper motors during that fast movement is plausible (no hint of blockage and lost steps), my first guess would be that one of the gears on the X/Y motors is slipping on its shaft.

It's a bit fiddly, but you should be able to check this without disassembling anything. You can see the gears through the large hexagonal openings in the motor mounting blocks (facing inwards). And you should be able to stick a small Allen wrench in there and reach the two grub screws which hold each gear, to verify whether they are tight and tighten them if necessary. Fingers crossed that it's this easy solution!

RE: Factory assembled Core One+: Printer decalibrates during print ?

Hopefully it's the loose pulley problem. Something is amiss from the start compared to mine. My initial nozzle squirt ends right on the hole in the build plate, not 5-10 mm behind it. I'd think that all the units and build plates are similar enough not to see that much difference. Did the head explore the plate at the correct 20-40 positions needed just prior to when the video starts? I've been under the assumption that the print is located in the center of the build plate, so the head should move at high speed from the end of the first clean-out squirt to the center area of the plate. Or is the print purposely offset?

RE: Factory assembled Core One+: Printer decalibrates during print ?

Hello again, thanks for all the effort !

I have as well the impression, that fast movements put the printer out of position. I was now opening the plexiglas on the top and checked about all the screws in there for being fixed (I found no one really loose). I tightend those, which I thought could be a bit more tightened, especially those on the xy-motors (4 screws at each side, in addition to those at the roles). After that I went through all calibration steps again (since the printer demanded that) - everything on "green ok" again. Finally I took another try on the model (see above). This time the printer moved to the middle, but still gets depositioned after every fast movement (see picture).

To the point of position of the plate: I tried several positions (the last in the picture is - I think - the one proposed). Still no real effect.

Another idea I could think of would be to renew the firmware - is that of use ?

Thanks again for any help or more ideas.

The first place to seek help with a new printer (or a new built kit) is Prusa Support via chat - you will need the serial number of your printer.

Whilst they are tested and leave the factory in good order Prusa have no control over couriers and baggage handlers so sometimes they are subject to rough treatment during delivery; support will help you get it going or even arrange return/repair if needed but also, if caught early enough, they can sometimes trace poor handling hotspots and troublshoot delivery with the shipping companies...

Cheerio,

RE: Factory assembled Core One+: Printer decalibrates during print ?

@diem: could you tell me how to contact support (I didn't find any location on the homepage) and where to find the serial number on the printer ?

Thanks a lot.

Martin

RE: Factory assembled Core One+: Printer decalibrates during print ?

Good morning Martin, 
the Chat link should appear after a short pause on the Prusa main page    https://www.prusa3d.com/

the Chat link should appear in the bottom right hand corner of the page, after about 3 seconds of the page content appearing

Some folk report issues with their browser not showing the link... 
I am using Brave Browser, which does show the link. 

Regards Joan

RE: Factory assembled Core One+: Printer decalibrates during print ?

Posted by: @martin-wasmann

... where to find the serial number on the printer ?

The serial number can be found on the sticker in the back of your printer, as well as on the thermo-printed quality check slip. It starts with "SN...". 

At least for me, the number was not printed on the invoice or delivery note. And, slightly confusing, a "serial number" can be displayed via the firmware (Info > Version Info), but that is not the one you want -- I think that one related to the main board only. 

RE: Factory assembled Core One+: Printer decalibrates during print ?

Hey. In case you have any issues with connecting to livechat from the window not showing up (should be cashe/cookies/adblock related) then you can try to connect via this direct link instead: https://direct.lc.chat/9644675

RE: Factory assembled Core One+: Printer decalibrates during print ?

Hello to all,

thanks for all the useful replies (besides their usefulness, they give me the good feeling of not being left alone with the problem ...).

I found the serial (SN) number and am now preparing a collection of pictures showing the problem of the xy-displacement as exactly as possible.

So long ...

Martin

RE: Factory assembled Core One+: Printer decalibrates during print ?

I seem to remember somewhere, there was a similar issue that was caused by the grub screw on the X or Y motor pulley that was not binding against the flat part of the motor shaft. This was on a factory assembled printer.  

RE: Factory assembled Core One+: Printer decalibrates during print ?

Thanks, for replying. I checked those screws previously (they seemed ok ...). I was in live-chat before and they asked me to check the belt tension. I will do this tomorrow or wednesday (today no more time). I will get back when I succeeded with those tests.

Martin

RE: Factory assembled Core One+: Printer decalibrates during print ?

Posted by: @martin-wasmann

I have as well the impression, that fast movements put the printer out of position. I was now opening the plexiglas on the top and checked about all the screws in there for being fixed (I found no one really loose). I tightend those, which I thought could be a bit more tightened, especially those on the xy-motors (4 screws at each side, in addition to those at the roles). After that I went through all calibration steps again (since the printer demanded that) - everything on "green ok" again. Finally I took another try on the model (see above). This time the printer moved to the middle, but still gets depositioned after every fast movement (see picture).

You have misunderstood, I think. I was not talking about the screws which hold the motors down to the XY frame. But about the screws which hold the pulleys (gears that drive the belts) to the motor shafts.

Those pulleys are attached to the shaft by two small black grub screws. And you can see and tighten these grub screws through the large hexagonal holes in the motor mounting blocks. (Visible if you look from the inside of the printer outwards.) Sorry, can't find a photo online, and I am not near my printer at the moment.