I am looking for a listing of the required torque settings for tightening the bolts on my machine during maintenance. I have seen many posts online about bolts coming loose - especially in the print head. I want to avoid this happening if possible.
I can’t find anything in the Wiki.
TIA
Welcome to the fourm.
There are none. Not trying to be smart, but there are none. Even still there are a few that are screwed into plastic. I usually go 1/4 turn past once tightened. I usually turn any others to about 1/2 to 2 (feel really)
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Yes it’s absurd they don’t publish this spec, surely they have them for manufacturing. You just need to make your own estimate.
Thanks for the responses. I was afraid that would be the answer. I’ll see if I have any luck with contacting Bambu Labs directly. In the mean time, I’ll be sure to use locktite on everything.
This is the closest thing I found in the Wiki:
Some of their screws have it on already, so at least that will give you a head start in identifying the ones that need it.
If a screw already has Loctite on it, but it’s loose, there’s some other mechanical problem.
Some screws thread in to plastic, and normal Loctite will attack the plastic. Other screws go in to inserts set in plastic. You don’t want Loctite near the screw in the first case, and you don’t want any “spillover” from excess in the second case.
I’d just go around the machine snugging each screw. If it moves, make a note. Don’t try and crank down any that are snug already, you’ll be making it easier for them to back out later. Especially if they have Loctite, you’ll be breaking the bond.
Check the screws that moved again in a couple of months. If they’re loose again, remove, inspect, use Loctite if appropriate.
On the a1 I would not go exploratory taking screws out, as mentioned upstream, many are threaded into plastic and prone to breaking… and don’t actually hold in the thing you think they do, especially the toolhead. Check the wiki for the part you’re trying to remove and it will define the specific screws to be taking out.
The 4 screws that really want loctite also need to be able to withstand nozzle temps – as they are on the heat block, nestled right next to the heater core. so you can’t just use regular red/blue. Even “high temp” generally available loctite 246 is not rated high enough - 450f/230c. You’ll be spending more in glue than replacements, but I guess if you have some on hand let us know how it goes.
I found Vibra-tite threadlocker rated to 1000C
While there isn’t actual numbers for torque settings, this wiki guide gives you pointers of which screws to find and tighten in the hotend.
The giveaway is if you’re getting “cat tongue” and wavy effects on the first layer.
Here is the response I got from a support ticket requesting torque settings. Makes me cringe but we’re stuck with this situation.
This may vary slightly from machine to machine, so it is not possible to define a unified torque value. The tightening should be adjusted based on the current feel and condition during operation.
From all of the loose fastener reports, I’ve come to the conclusion that Bambu Lab does not have tighten-to-torque manufacturing specification, so it’s no longer surprising that support can’t offer you anything other than “tighten it, but not too tight”.
I don’t see how you can manufacturer anything without a torque specification for each fastener, but maybe in China you can just tell all of the workers “tight, but not too tight”.