Printing head calibration going wild
Hello,
I'm not sure if this is normal behaviour since this is my first printer ever, but as you can see on the video below, the printing head keeps banging in the front right corner every time I start a print. Both belts are tuned to 85Hz.
Yesterday I printed Benchy, and the printing head was also banging the corner, but for much less time. Eventually it started to print, but this time it's been doing this for over 3 minutes...
Please advise,
Thank you!
RE: Printing head calibration going wild
SOLVED!
I had to bent gantry a little bit and re-tune the belts.
RE: Printing head calibration going wild
This is such an annoying issue. Prusa need to add an option for it to stop and either produce an error, or just carry on regardless. At the moment the only option is to wait, or reset the whole printer!
RE: Printing head calibration going wild
So what is the answer for this, I have the same problem.
RE: Printing head calibration going wild
how exactly did you bend the frame? Do you have any pictures and a more detailed recommendation. I am having the same issue - it's impossible to calibrate the X and Y axis. The printer head is always banging in the top right front corner.
RE: Printing head calibration going wild
Support will send you a video on how to adjust the gantry. I have done it by following their directions and it is quite easy once you figure it out.
It is very important to loosen up both sides of the belts, completely. Although you can bend the gantry OFF square by bending/pulling one side without loosening the belts, you will be putting stress on the belt adjuster/pullies and you will pull them off or break them in half. Ask me how I know.
So best is to loosen the belts completely, THEN, bend the gantry to get it square, confirm that both sides are square to the front, THEN, re-tighten both belts. I have since tuned my belts several times and this method makes both tuning the belt and squaring the gantry up very easy, without damaging the belt tensioners (it is a 3d printed part).
My machine came with both incorrect belt tension and off square gantry from the factory. After tuning the belts correctly, I had to re do it again as the belts came loose (both sides showed to be 80hz instead of the 85 I had them at). No idea why that happened, maybe one of the adjusters had not slid properly and it came lose while printing, loosening the belt ( you will see in some cases the screw wants to pull out rather than sliding the adjuster in/out). This might not make sense now but it will once you do this process once.
All that to say, once I got both the proper tensions things improved generally speaking. Most notoriously was that the homing sequence at the beginning of every print is now consistent rather than banging indefinitely.
RE: Printing head calibration going wild
All clear, thank you so much for your help.
I'm embarrassed to say, but the root cause of my problem was the incorrectly mounted pulley. Once I took this all apart and correctly mounted it, everything worked like a charm 🙂 😋
RE: Printing head calibration going wild
Regarding my issue with head calibration. I had a chat with Support and they advised to ensure the chassis was contacting evenly in the front and to then recalibrate the belt tension. This worked for me. I have attached a video that support acknowledged as normal behavior, knowing what's normal is a big help for me.IMG_2812
RE: Printing head calibration going wild
Do you have the video support sends with the instructions?
Support will send you a video on how to adjust the gantry. I have done it by following their directions and it is quite easy once you figure it out.
It is very important to loosen up both sides of the belts, completely. Although you can bend the gantry OFF square by bending/pulling one side without loosening the belts, you will be putting stress on the belt adjuster/pullies and you will pull them off or break them in half. Ask me how I know.
So best is to loosen the belts completely, THEN, bend the gantry to get it square, confirm that both sides are square to the front, THEN, re-tighten both belts. I have since tuned my belts several times and this method makes both tuning the belt and squaring the gantry up very easy, without damaging the belt tensioners (it is a 3d printed part).
My machine came with both incorrect belt tension and off square gantry from the factory. After tuning the belts correctly, I had to re do it again as the belts came loose (both sides showed to be 80hz instead of the 85 I had them at). No idea why that happened, maybe one of the adjusters had not slid properly and it came lose while printing, loosening the belt ( you will see in some cases the screw wants to pull out rather than sliding the adjuster in/out). This might not make sense now but it will once you do this process once.
All that to say, once I got both the proper tensions things improved generally speaking. Most notoriously was that the homing sequence at the beginning of every print is now consistent rather than banging indefinitely.
RE:
This is how I fixed my gantry: https://www.youtube.com/watch?app=desktop&v=myLZtFy0nhw
Just don't bend too much at once, bend a little bit and then check. Repeat until you have no play on each side.
RE: Printing head calibration going wild
That's great, I did not know these videos existed!
Thanks
RE: Printing head calibration going wild
Important:
Do it like in the video, but keep an eye on the belt tension! One belt, depending on the side you're pulling, will tension up A LOT.
You want to bend the brackets of the linear rail, NOT stretch the belt (or rip it off, snap it etc.).
So pull slightly, check if and which belt is tensioning up and make it more slack, before pulling further.
RE: Printing head calibration going wild
£1130 / £874 for an assembled / kit printer and you have to arbitrarily bend bits and guesstimate by eye whether you've got it right, then re-assemble / re-tension belts only to find you were a bit out and then repeat until it works. This doesn't fit the 'Prusa quality' image.
Surely Prusa can come up with a more accurate process to produce their parts - or at least come up with a more accurate user process to correct their manufacturing shortcomings (check diagonals of XY assy are equal or provide a frame to guarantee 90 degrees in corners?).
RE: Printing head calibration going wild
Best practice as per support is to loosen all belts completely. No issues of ripping or stretching anything then.
RE: Printing head calibration going wild
Surely Prusa can come up with a more accurate process to produce their parts - or at least come up with a more accurate user process to correct their manufacturing shortcomings (check diagonals of XY assy are equal or provide a frame to guarantee 90 degrees in corners?).
I guess, that the brackets are designed to bend, before the Y-Axis bearing can get stuck and damage the printer.
That wouldn't really be an issue, if the calibration wouldn't be, what it is..
I have no idea who came up with the idea to bang the print head multiple times against the end-stops, without some sound dampening.
I also absolutely don't know why Prusa thought it would be a good idea to annoy 99,99% of customers for 99,99% of prints , just to get an almost invisible seam, if a power outage happens.
If no power outage happens during a single object, half a millimeter off-set wouldn't be an issue and there wouldn't be the need for more than one bang per axis. *tock* *tock*, printing.
This extra accurate banging should be an optional setting for power outage protection..