hey guys, so i know there are no limit switches for X and Y, and homing is done “sensorless”.
My brand new (well 10 prints old) A1 mini makes a “thunk” sound specifically when homing Y axis.
Please see video:
I hear this “thunk” a few times before starting each print.
is this “thunk” normal? I fear repeated homing with this force may eventually wear something out.
Thanks in advance
I can’t see from the video, but there is something behind the printer.
Check that the bed isn’t banging on whatever is behind the printer.
Edit: Is it hitting the S2 Dryer…??
That was what i thought initially, but i’ve moved the dryer back quite far (nothing is blocking the y axis).
Can you make another video showing from the front top so we can see the bed moving…??
If not, 3-4 pics with the bed all the way pushed back might help.
More videos of what’s happening… Looking at the rails, it’s basically hitting the end with a bit more force before stopping. This leads to the the sound.
Perhaps the current threshold that triggers the stop is too high?
Hi
have you solved your problem?
I have the same problem and roughly the same sound, but with the A1 (without mini)
I think the carriage is a little too far back, so that it hits the stop when moving.
If I look at the silicone scraper part from the side when cleaning the nozzle, then it only scrapes the front edge, if at all.
This supports my theory that the carriage is positioned a little wrong.
This is not noticeable when printing, since the ratios on the y-axis do not shift relative to each other.
Is there a way to calibrate the travel distances from end stop to end stop in all axes, or even one?
Best regards
Response from Bambu to my support ticket:
Dear Bambu Lab Customer,Thank you for reaching out to our customer support team. I am sorry to see that you are experiencing problems with our product. We will do our best to assist you and provide a solution for the problem you are facing.Judging from the sounds in the video, there are no abnormal sounds that may affect printing. The slight collision sound and the sound of the ball sliding on the slide rail are reasonable
@willi my guess is it might be normal!
Ya, I thought it sounded normal when I watched it again last night.
Sensorless Homing has to bang a little.
I think your table or enclosure is amplifying the sound…JMO
thanks @lion7718
yes, i only started noticing the sound after i put the printer on my desk…
previously when it was on the floor I didn’t even realize there was a sound.
My A1 does it too I believe it’s normal
Fixed the issue with a bumper.
Took some creativity to trace out the shape but this works. Using TPU. But u can print in pla and then stick on some foam as well. Use the stl as a template to cut foam to shape.
Could be useful for sound connoisseurs who are picky about sounds the printer makes 
That makes a lot of sense! Will evaluate to see if this affects my printing
Can u share more details on the inductive sensor? Ie. When does it sense, only during homing? It’s not often the carriage is at the end stop
The only problem is this offsets your y axis calibration which should be fine as long as you dont print towards the very top of your plate, then there could be a problem, though depending on how thick it is that would change how it would affect the print,just warning you.
My A1 mini started making a very similar cringe + thunk sound on the Y axis but on the opposite side 
It was fine before. Now, it started making these sounds, and also, when it does all the sensor tests at the beginning of each print, you can clearly see that the Y axis is a bit further toward the front of the printer. No other issues during the printing process, though.
Is there a way of resetting the Y axis? or fixing it? 
I think this has to do with what as found in this post… It seem the
M1005 command does not have an end stop so the printer is trying to go beyond. I would think someone noticed the printers trying to “Bang their head against a wall” and adjust that…
What was recommend was to send …
M1005 I0
then
M500
to save it.
Not sure if this is the same for the A1 mini, but I will try on my A1 and see. I have a newer one and the heatbed start to overheat, and then shut down the job during calibration, this I think one of the lines is getting knock loose during the 21 times, that it slams the Y-axis all the back during Calibration and