I did something I never do - I overtightened a screw. I was doing maintenance on the belt tensioner (back of machine) and I over torqued one of the screws. I heard a snap and now all of the screws (both sides) do nothing. I can’t tighten or loosen any of them.
Anyone know how to fix the spring tensioner? I really don’t have any idea.
Thanks
Edit: The cheap-a** allen key I was using (it came with the printer) was slightly undersize, so when the screw I was turning got tight, it slipped, making a snapping sound. After which, it wouldn’t turn any of the screws!
Note to Self: Don’t use cheap tools!
Thank you to all who responded to my plea for help.
Thanks
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The screws only lock the tensioners in place. They don’t actually tension the belt.
Luckily the replacement parts are cheap and available.
Here is the wiki guide for replacing them, it may also give you good insight on how they assemble so you could possibly fix them.
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What may of happen is that the brass threaded insert may have pulled out of the part behind the pulley housing. You may be able to heat them up and reseat them.
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Just got home from work. Thank you for such a complete answer. I searched for the answer, but obviously not well enough.
Thank You
I do prefer to fix rather than replace when I can, so I will see if repair is possible.
Thank you.
You ever get this sorted?
I’m having the same issue. I don’t think I over-tightened, because the plastic tensioners have heat set size holes in them as well…
Waiting on support to get back to me, but with Lunar New Year and the A1 stuff, they seem to be way behind.
LIlac, I did. As it turns out, I used the allen key that came with my printer. It’s just a little undersized, so when I used it, the key slipped in the socket of the screw, causing a little “snap”. After that, the screw wouldn’t turn. I thought I had broken something.
When I used another tool, it worked fine. I can’t tell you how relieved I was to discover that I hadn’t actually broken anything.
If you have, please refer to the post Jon made back to me. It will point you to really great information in the form of a Wiki from Bambu Labs.
Thank you to all who responded to me about my problem.
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The provided allen wrenches are a joke and I’d honestly not recommend their use. I learned that when I first tried changing my hotend out and noticed that the allen wrench would bind in the hex bolt; it wouldn’t do that if it was properly sized.
Glad that was your only problem though, as that would have been annoying to have to order new parts to fix. I pulled my own idiot move a couple of days ago when I wasn’t paying attention to my build plate and my nozzle ran into parts I forgot to remove and bent it. Thankfully I still had my spare 0.4 nozzle. 
I bent a hot end in a similar occurrence. Unfortunately for me, there was plastic completely encasing the hot end. As a result I was unable to remove the thermistor and had to order a new hot end.
