Nut on heatbed destroyed
Hi!
I accidentally destroyed one of the 5mm spacing nuts in the middle of the heat bed by, well, applying to much force. My bad, I guess, I hadn't expected that so little force could be too much. But a 5mm nut is a bit optimistic, no? Could you not have 8mm at least? So that each screw has a fine 4mm of space to attach to?
Well, anyway, those are standard 3mm nuts, I guess, and I have some 5mm long ones in my tinker drawer, but I don't dare to unscrew it, because the counter screw is below the PEI sheet, so I will not reach it with a screw driver unless I remove (or destroy) the PEI sheet, right? Very unfortunate.
I don't like the current setting with a loose screw in my printer -- it's only a single 3mm screw now that moves the bed.
Any ideas what I could do to improve my situation without changing the PEI sheet? It's still quasi brand new!
BTW: I had tightened the screw after the bed started making some rattling noise while printing, and I though something was loose. I could not find anything, however, despite being able easily to reproduce the rattling by slightly pushing or pulling the heat bed in Z-direction in some places. I have no idea what is loose, I had checked all zip ties, all screws, everything. Still, the rattling sound remained. And then, I overtightened that screw. 🙁 It's still printing, and I am currently printing a support for the belt mount under the table in order to keep some of the force from the 3mm screw and instead transfer it via some kind of plastic bracket directly into the aluminium mount. *sigh*
Re: Nut on heatbed destroyed
I think you will be fine with just the single screw done up tight.
These beds do vibrate quite a bit, I think a lot of the noise comes from the motors and how they are attached to the frames. Try printing some anti-vibration feet; they will help.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Nut on heatbed destroyed
No, no, it's not the vibration in general. I actually have anti-vibration feet already, which I printed because some fill patterns sounded like a distant lorry when the table under the printer amplified that noise quite a bit. But that's not what I had searched for here. In fact, I am very happy that the printer is quite quiet now.
No, the rattling is very specific, and it appeared only two days ago. And, as I said, I can move the table slightly and actually feel that somewhere, something seems to be loose. But I cannot pinpoint, feel, see, hear, where exactly. Maybe inside one of the guiding ball bearings? No idea.
What's the heatbed made of? Is it epoxy? Because I may want to glue some support to it, because I am totally not sure I should trust that single screw...
Re: Nut on heatbed destroyed
Heatbed is FR4 glass-reinforced epoxy laminate.
I think you may have to trust a single screw.
Regarding the rattling, it could be a bearing; not a lot you could do with that other than apply a grease to take up the slack or to replace it.
Also take of the anti-vib feet and ensure that all 4 feet are level.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Nut on heatbed destroyed
Regarding the rattling, it could be a bearing
I'm almost sure it is a bearing. I have the same problem. There is about 0.5mm clearance between bearings and rods, it is too much.
Re: Nut on heatbed destroyed
David
Have you tried printing replacement bearings?
I did a few using PLA - made then as long as O could - the side with 2 bearings I made into one to reduce lateral play.
Seems to have worked quite well, but I don't know how long they will last - I am still in the process of building an modded Mk1 with the plastic bearings.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Nut on heatbed destroyed
Hi,
I just tried switching default Y rods for more precise quenched rods (I hope "quenched" is right word in english) and its noticeably better. With this rods, clearance between bearings and rod is smaller, at least in my case.
I have original IGUS plastic bearings, but havent tried them yet on i3. I have some doubts about zip tie attachement in combination with plastic bearings (they are not super hard) .
Re: Nut on heatbed destroyed
No, no, it's not the vibration in general. I actually have anti-vibration feet already, which I printed because some fill patterns sounded like a distant lorry when the table under the printer amplified that noise quite a bit. But that's not what I had searched for here. In fact, I am very happy that the printer is quite quiet now.
No, the rattling is very specific, and it appeared only two days ago. And, as I said, I can move the table slightly and actually feel that somewhere, something seems to be loose. But I cannot pinpoint, feel, see, hear, where exactly. Maybe inside one of the guiding ball bearings? No idea.
What's the heatbed made of? Is it epoxy? Because I may want to glue some support to it, because I am totally not sure I should trust that single screw...
I don't know why any acceleration isn't added to the starting script for the Slic3r or Simplify3D profiles provided by Prusa, but try adding "M204 S1000" or "M204 S750" to the starting script (lower number means "slower" acceleration). The acceleration will make your prints slower by a small amount, but that scary rattle you get when the extruder makes small moves without having acceleration is somewhat scary and will probably make more than one screw/nut loosen way earlier than it should.
/Sascha
Re: Nut on heatbed destroyed
New Slic3r can control acceleration "natively", so there is no need for starting script..
Re: Nut on heatbed destroyed
New Slic3r can control acceleration "natively", so there is no need for starting script..
Haven't used Slic3r for some time and forgot that it had those settings.
No matter, only adding that line to the starting script is sufficient anyways, and it works on both slic3r and S3D
/Sascha
Re: Nut on heatbed destroyed
those short threads in the spacers under the heatbed are a complete joke, why do they have to be so short and weak?
I have also two broken ones...
and by the way I am also facing strange rattling noises
posted a Video here: https://www.facebook.com/groups/Prusai3users/permalink/683044008546750/
Re: Nut on heatbed destroyed
I was able to get rid of the rattling of the build plate by doing the following:
-Find a bolt that will wedge between the build plate and xframe.
- wrap the bold in high temp silicone tape ( http://www.xtremetape.com/ )
- secure the bolt between the xframe and built plate with a zip tie.
-find the optimal place to zip tie the bolt wrapped in silcone tape by tapping the build plate with your finger
- The tension on the zip tie is light.
-do not place the bolt near one of the 9 calibration points
Update: In giving this more thought, I bet just a ball of extreme silicone tape placed between the build plate and the X-frame would suffice, but my current solution is working well since the December so I don't have any motivation to change the setup.
Re: Nut on heatbed destroyed
If you have access to JB weld metal epoxy, you could make a replacement part or even fix the broke part.