What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?  

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

You may get guidance from the support chat, but I would imagine a high temperature epoxy resin adhesive would be the thing.

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

You may get guidance from the support chat....

Well, maybe, but whatever Prusa used apparently wasn't good enough.

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

You may get guidance from the support chat....

Well, maybe, but whatever Prusa used apparently wasn't good enough.

You have had two magnets drop out. Prusa have shipped thousands of these heatbeds. I think we may have heard about it before now if it were a common issue. Maybe your bed didn't get enough glue on those two...

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

Maybe, silicone sealant!

I have sealed model aero exhausts with it, and even temporarily glued a coke can skin over a hole in a motorcycle silencer, whilst waiting for a replacement to arrive... I think it would stop the magnets escaping

joan

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

I just remembered that I already own some high temperature aluminum foil tape for sealing boiler ductwork and the like. It's made to standards and meant to last indefinitely. I think I'll give that a try rather than buy yet another thing just to glue two magnets.

Thanks for the suggestions!

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

I had one arrived fallen off (stuck to an adjacent one).
I used high temp epoxy from a hardware store without trouble.
Prusa confirmed that suggestion as well.
I used wax paper and a binder clip to hold the magnet in place while the epoxy cured.

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

This is probably not so uncommon, most people will just glue the magnet back. I've also had 2 magnets drop off already.

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

Maybe, silicone sealant!

I have sealed model aero exhausts with it, and even temporarily glued a coke can skin over a hole in a motorcycle silencer, whilst waiting for a replacement to arrive... I think it would stop the magnets escaping

joan

you have lived an interesting life.

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

Hi Chris,

I have a different outlook on life to some folk,

which can lead to interesting solutions. 🙂

regards Joan

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

I just superglued mine back in - clearly not the proper glue for this job, but it still does a much better job than whatever stuff Prusa used.
(I had 8 magnets in total fall off in the first few weeks. Only happened on ABS prints btw, 90-100C).

Would be much better to seal them all with epoxy, or at least tape over with something appropriate. Maybe the MK3.5 will have a more robust design OOTB 🙂

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

I just superglued mine back in - clearly not the proper glue for this job, but it still does a much better job than whatever stuff Prusa used.
(I had 8 magnets in total fall off in the first few weeks. Only happened on ABS prints btw, 90-100C).

Would be much better to seal them all with epoxy, or at least tape over with something appropriate. Maybe the MK3.5 will have a more robust design OOTB 🙂

Actually, I did the same. I used the shock resistant kind. It just seemed neater, and I had an already opened tube. I figure if it didn't work, I would tape it. It has held, at least so far. I guess a bed temp of 90C is within its range.

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

Is there a picture or diagram showing where these magnets are located? Before my hotend went bad "and I'm about to install the replacement" I had problems with calibration not finding points on the bed.
Since these magnets can come loose maybe checking for them once a month or something wouldn't be a bad idea?...

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

Good (?) to know I am not the only one who is having magnets fall out. Two so far. Just super glued them in for now. If they fall off again, will try some high temp epoxy.

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

I had 3 more magnets detach just recently (for a total of 5 now):

Rather than play the game "find the lost magnet" again, this morning I Kapton taped over all of them

It won't keep them from detaching, but hopefully they'll hold their position if they do. 🙄

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

I just glued 12 magnets back in using high temp silicone gasket adhesive from an auto parts store. Good to 351c.
Originally two had fallen out but the other 10 fell out while I was replacing the original two. The last hundred hours or so were printing at a bed temp of 100c.

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

I think what's happening is that the spring steel tends to THWACK! into place, and the impact of that is knocking the magnets lose from their Prusa glue, which apparently isn't very impact resistant.

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

Is there a picture or diagram showing where these magnets are located? Before my hotend went bad "and I'm about to install the replacement" I had problems with calibration not finding points on the bed.
Since these magnets can come loose maybe checking for them once a month or something wouldn't be a bad idea?...

the magnets are not used when calibrating x/y , they are only there to hold the springsteel. when the printer calibrates x/y the pinda is looking for disk shaped pcb traces which are done in the same etching process as the pcb heating traces.

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

So, we're having the same problem (a third of the magnets falling off all of a sudden), and have a good high-temp industrial glue we were already using for a manufacturing process here, but one magnet has vanished entirely (looked high and low, not stuck to the under side of the printer far as we can tell, etc.), and another one broke in half.

Is there a recommended replacement magnet, or should we just go get some that are the right size and shape and be done with it?

Re: What kind of glue to use for re-attaching magnets that had fallen out of the heat bed?

I would contact support to see what they recommend for the magnet replacement.
Getting the right size magnet that is really Neodymium is a bit hard to do.

I got lucky and found the missing magnet on top of one of the bearings hiding along side the carriage.