so… did something stupid was watching a purge… then nothing was happening so I got a little closer and leaned my arm on the table, the second I did that my A1 min bed SLUNG forward at full speed and hit my arm. Heard the belt skip so I killed the printer and ran vibration compensation.
Through an error for Y belt… so obviously I damaged it.
Is there other parts i’m ganna need to? Is the pulley on the motor going to be damaged too? Never had to replace a belt…
Thanks
Taking photos would be a good idea right now. It’s possible that nothing is broken and you just need to factory reset it - or that all kinds of things are damaged. You are standing in front of the printer; we cannot see it. 
Try doing a factory reset and taking a few photos, and then maybe we can judge more accurately; otherwise, we can only guess. Maybe you’ll get lucky and the factory reset will do the trick. This forces the printer to recalibrate itself.
Also check whether everything can still be moved by hand to the end of its range without grinding or strange noises - when the printer is switched off, not when it is on. Check the belt tension, too.
…and if everything looks good, I’ll do a reference run, also known as homing. This can be accessed via the printer menu, the house icon.
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Well, I got the bottom off the printer already, was going to take the belt out to inspect it, can’t see much with it installed.
Everything moves it wasn’t a crazy hard hit, just chewed the belt pretty good. I already ordered a replacement.
Theirs really nothing to see externally, it just banged my arm that was planted on it the table, it didn’t get knocked off or anything like that, but I heard that belt skip…
turned it off, turned it on and ran the vibration compensation and got the “y belt high latency” error.
Belt is still quite tight, here are some images but just because a belt doesn’t look worn… doesn’t mean it isn’t when your talking precision stuff.
Here lemme get a better one, can’t use my phone for this and have to hold a flashlight at the same time, hard to make my mini cam snap a pic without shacking while pressing:
You can see it here: Definitely chewed er up. only has 500 hours on it.
Also… this belt isn’t toothed all the way around… so now wouldn’t the belt need to be put back where it was? And the replacement direction say:
From bambu wiki
According to the image below, use instant glue to connect the end of the new belt with less teeth, to the end of the old belt with more teeth. Refer to the image below.
WHY AM I CONNECTING A NEW BELT TO AN OLD ONE? that makes no sense.
Glueing the belt and following the old with the new is a reflex for how to handle corexy re-belting. The best way to thread corexy is by letting the guy who did it before do it again, with glue 
That process is so easy to get a wrong twist on.
I guess I won’t understand until I get the belt off. I can’t get it off the Y motor pulley theirs still not enough slack.
Can you explain that a little more bullocks? I’m still not fully understanding.
I CANNOT get this belt off… i’m noticing in the instructions this dude has the entire machine disassembled. The whole top is gone…
I’m worried now. My entire machine is unfixable because of a 12 dollar belt… this would be way too Ender 3 like to be real. Hope someone can help me understand this belt gluing.
Glue the old belt to the new one so that you can pull it through more easily. Otherwise, you would have to dismantle even more. Use the old belt to pull the new one through to prevent it from twisting as it goes through all the openings and holes.
It’s just like when you install new wiring in your house: instead of simply pulling out the old wiring, you connect the new wiring to the old wiring. Why? So that you can pull in the new wiring.
You could use a rope or something else to pull, but why use anything else when your old belt does the job perfectly well and is readily available? Further advantages: nothing twists. The alternative would be to dismantle the entire printer. That’s why it’s important to let the glue dry and set firmly, and then pull slowly and gently.
After that, you can throw away the old belt anyway, as its only purpose now is to pull the new one through.
hmm… thats confusing since their instructions show removing the old belt from the pulley.
Also the belt skipped… do I need to skip it back to save the timing?
Thanks for pointing that out. Apparently i’m the only one who has ever had to do this, because if you type replace bambu a1 mini y belt into google, THIS post comes up hahaha.
So you rip the old off the plastic retainer, glue the new belt into its place, pull the new belt through-rip off the other side of the old belt, and then glue the next belt on?
Are there any old videos or posts you know of? Each video i’ve seen is a different type of belt where they aren’t glued in.
I CANNOT open a bambu ticket because I need printer log files… When I put those in it won’t take them.
Thats the A1 guide, on the mini it actually shows to REMOVE the belt.
Push belt off edge of Y motor, then it comes into gluing the belt on. A little different!
I might just buy a new printer… I’m ganna screw this up. Can’t really afford one at the moment because I won’t be getting an A1 mini.. gotta have a p2s at this point lol.
You’re right, I just uploaded the wrong photos, but the procedure is the same. You pull in the new belt with the old belt.
We’re talking about this guide?
Yep thats the one. I tried to remove the belt from the y motor for like an hour, its still way too tight with the tension spring disengaged and the tensioner all the way loose, it aint just slippin off!
OK, I’m starting to understand what you mean now. I had to work it out for myself first, but I can see why you’re getting frustrated. The passage you refer to is poorly written and lacks information. I need to think about it myself first. As I said, now I understand what your problem is.
I think I know what the problem is, maybe, possibly:
Did you accidentally loosen it completely? If you loosen it completely, it could get stuck and jam?
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Either way, it was foolish of Bambu not to record a video straight away. It’s not much more work than taking photos. You really seem to be the first person to ask about replacing it. I couldn’t find a single post about it on the forum, YouTube or Reddit.
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Edit: He also seems to have problems with this, not with the belt, but with this tensioner behavior on the A1 mini.
https://www.reddit.com/r/BambuLab/comments/1oxq674/y_belt_tensioner_behavior_on_a1_mini/
I loosened it one turn, then a little more. I didn’t loosen it all the way as I have done the tensioning procedure after 500 hours.
There is a TON of slack on the belt, just not enough to get it off yet.
I try prying at it when I get home from work!
Thanks for looking into it.
I placed an order for a new mini belt. Interestingly the new belt seems to come with the plastic carriage.
Perhaps this is a little easier than the standard a1 where I just assembly it and put it on?
I suppose you do need to split the belt while its on the track, because there would be no way to get the new belt through the pulley.
My thought:
Tear 1/2 old belt off plastic carriage, pull belt out.
“glue the old belt to the new belt to carefully pull it through the tensioner” So you need to glue the two pieces together temporarily to pull the new belt through the mechanism, then rip the old and new belts back apart… THEN proceed to glue both belts to the plastic? I hope this will make more sense when I have the replacement in my hands.
Problem here is, unless I can push the belts over the pulley, its going to be extremely difficult to glue the new belt together on the plastic belt inside in the machine… I really need to figure out a way to get enough slack to push the belt on and off the motor!
Update: There is NO WAY this belt is coming off, I’m going to end up bending the motor pulley trying to do it, I can get part of it just over the lip but thats it. Tensioner is fully loose and spring is disengaged.
Something else is going to have to be disassembled, either the motor mounts or the tensioner mount… my belt is just too tight to follow the directions.
GOT IT! Wow is that an uncomfortable thing to do… will update possibly with short video on how the new belt goes. I think I know what i’m doing, and I have practice belt I got from work to try gluing them together to get through pulley.
My co worker said he recommends splicing tape instead of glue, ganna see what that looks like.
Should I put some lube between the idler pulley and housing while i’m here? It’s not very smooth feelin. Face of it had a lot of gunk on it I removed.
Putting the belt back on… 100 times more difficult. The entire frame is flexing trying to do it.. I wanted to see how hard it would be…
BAMBU PLEASE HELP. Am I supposed to assemble the new belt off the pulley and glue the ends after I wrap it around? I feel like I am breaking this machine.
Broke a frame screw fighting to get the belt off as show in the manual… greeaat.
Need to know: Does the belt go over the motor pulley while its cut in two? Or after I re assembly it?
It doesn’t seem possible to put it back on after assembly, theirs simply not enough slack. I’m shocked I got it off.
I hope none of you A1 mini owners have to go through this, a simple task is taking days and destroying my printer. Probably broke the motor too putting all that force on it getting the belt off.
I can’t answer your question, but I would like to thank you sincerely for sharing this, especially the photos. The photos are especially great. They are better than the wiki. It will help many A1 Mini owners with this problem. Thank you for your valuable contribution. I’m just an anonymous guy, but trust me when I say you’re making a difference. 
And when I see that, I hope I never have to replace the belt myself.
