After multiple attempts to fix my hotend fan Bambu sent me a new toolhead and x-axis assembly. Everything was going fine until the last screw - a vertical one holding the x-axis to the y-axis slider. I had removed three of them without problem but on this one I got the allen wrench just a little bit off of perfectly perpendicular and stripped the head.
Frankly, I cannot believe any competent mechanical engineer would put RED loctite on a screw without appropriate access to put heat on it to break the loctite. I figure I have one more shot at this thing - perhaps heating the allen key and carefully trying to get it into the screw head to transfer heat into it, and maybe, just maybe there’s enough torque capability remaining to get it out. There’s certainly no room to slot the head or get a pair of vampliers onto it. In this day and age nothing this small should be an allen head anyway - they should all be torx.
I might have more luck removing the Y-axis rod with the x axis and tool head so that I can see the screw and have a straight shot from on top as opposed to trying to do this blind from the bottom. That requires removing the two semi-circular clamps from the ends and apparently the “clacker” on that side, but they’s designed the damn thing such that the linear bearing is captured by some plastic on the side glass. If I can’t get the x-axis out of the left side bearing to give me more room I’m screwed.
They spent way too much time making this thing look nice and not nearly enough time making it repairable given that they have no US repair facility and even if they did, the ability to re-package this for shipping and the cost of shipping something the size of a kegerator would make it improbable anyway.
hey dude - the bots decided your reply was inappropriate - but I’m pretty sure I have more going on than you in the assembly and engineering departments. BSEE, Masters in Systems. Former Indycar Mechanic. Currently build, prep, and drive my own F4 car. I’ve put together hundreds of electrical assemblies during my career in navy R&D. Sort of know my way around wrenches - which is why I’m actually qualified to make the comments I made, as opposed to your comments.
I’ve considered that. I have some tiny specialized torx, but don’t know if I have any THAT tiny. I’ve sent a reply to Bambu, will wait to give it the heat until I hear back.
I really thought this ordeal was over - and on the last screw to boot.
I did get the Y axis out on the right side and then the X axis out of the left side and carefully got it upside down supported across the top - but no joy on getting the screw out yet.
It is specifically designed, unlike the blue one, to require heat to remove. It holds hard enough to damage metal parts if heat is not used. (edit and the OP was saying that applying heat to the print head is difficult due to its design)
If you have a soldering iron with a small enough footprint stick it up to full temp and heat the head of the screw up before wedging a Torx driver into it to gain a little more bite .
Are you saying that bambu’s red loctite is not standard, or that you misunderstand the use of the term “red loctite” and why the OP was commenting on the need for heat?
edit thinking about this some more, i’m interested in what brand your red loctite is that is so easily removable? You could remove it from something large like an M5 bolt without breaking anything but it’s highly dubious on something as small as M3. For the standard definitions of loctite, see How to choose the right LOCTITE® threadlocker | Henkel Adhesives whch is of course, from the loctite company. Red is classed as “permanent” and is safely removed by denaturing the adhesive with heat.
Your link is very misleading as many « red » loctite are available. For having removed a lot of « red » threadlocker on BL printers, they don’t need heat, they are tough but not that tough that it requires heat and certainly not a permanent assembly. I think it’s more loctite 262 or similar than any other red loctite you linked.
In addition the threadlocker is just on one dry spot on the thread and not on full thread like you would do if you applied it from a liquid loctite 262 bottle
btw, as part of the vortek upgrade kit in the x-y axis assembly box, bambu provides a better allen key driver for that very screw than the one included with the printer. I did not use it as I use my own tools but the one provided has less chance of stripping this particular screw and certainly why they included it in the kit.
Yes, as stated I have removed loctite red M5 nuts without heat, but it required vice grips on the shaft the bolts were screwed to, to prevent damage to the machine from rotating said shaft. So they are not “permanent” but I do not blame anyone from breaking a small precision machine part that was attached with red where they weren’t able to apply heat.
Had this exact thing happen to me a few weeks ago. That x-axis screw is a nightmare once it strips.
What worked was using a slightly larger torx bit and tapping it in gently with a small hammer. Gave just enough grip to break the threadlocker loose. Also second what philch said about the better allen key from the vortek kit - makes a difference.
Heat didn’t help me much either. Ended up replacing the screw entirely with a better quality one I had lying around. Worth keeping spares on hand for these.
We run a bunch of these printers at Syniix - we’re one of those Custom Software Development Companies in Alabama but we also do a fair bit of hardware tinkering on the side. Stripped screws are inevitable with these machines.
Good luck getting it out. Take your time and don’t rush it.
They supplied one of those small screwdrivers in the kit with the new toolhead. I was unable to apply enough torque with it on the subject fasteners. I was barely able to apply enough torque using the short arm side of the standard allen key when removing the top screws through the access hole, and thus I tried the same method on the bottom ones. Worked 3x…
Their red loctite description in the practical guide is pretty much the standard definition of red loctite everywhere. Now that I have a bunch of these replacement screws I’ll have to go out in the shop and run an experiment with standard red loctite and see if I get the same results.
This is a case when I would consider filing a bug against the design, or asking the engineer why they specified red. it’s not just the mechanical strength. If you tell someone a particular part uses red threadlocker, that statement itself is saying something about the design and maintenance process. In much the same way as an electrical wire colour code.
edit I bet if they used blue, the OP would not have a broken fastener.
I know space is premium but I think with a small enough driver you can use a screw extractor, just practice on a health screw to make sure you drill the right way.
I wouldn’t do that, it’s the perfect way to break the head off and the remaining screw with red loctite will be impossible to remove short of drilling it out and rethreading…
If the torx bit does not work, may be superglue on the hex bit, let it set and re-try, next would be JB weld and next… a touch of MIG/MAG between head and hex bit…
Well screw extractor kits are basically for drilling out, if you use a small enough bit correctly should extract out easily. These bits also work without the hat btw. Fairly inexpensive and you can try out before. I don’t think red loctile can hold against these but you can heat the bit and hold on the screw for a while before turning.
