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?

Posted by: @karl-herbert

@wilko

Maybe you try this product: https://www.amazon.de/gp/product/B00GFACVWO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I use it very often on the printer for heat resistant applications. I print PEEK at bed temperatures of 140 to 150 degrees C. and I have not lost a magnet yet.

Thank you! That is a good tip, Harl-Herbert!
I had my girlfriend order a tube of that in Germany.
Let's see how well it works!

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

Hello all,

Today I had 5 magnets fall from the bed when I replaced the steel sheet after a print.  My heated bed is a Mark 52 on a MK2.5S printer.  I will try to use Loctite Red or JBWeld with sanded magnets.

Before I do that I do have another question which I didn't see asked in this thread:  does the magnet polarity matter when I put them back or I can just pop them in in any orientation?

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

@printer

You can easily test this by moving the magnet towards the spring steel plate. Normally, the installation direction should not make any difference (only magnet - magnet).

wbr,

Karl

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

In the US, I use JB Weld to permanently attach them.  

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

@karl-herbert

Thanks! That's what Prusa support told me as well: that polarity doesn't matter.

@cwbullet

I'll use JB Weld and I plan to lightly sand the magnets on the glue side.  I'll do this without disassembling the bed.  What do you recommend to keep them in place while curing?

soln

I used JB weld and add a layer of 15mm Kapton tape.  

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

I'm in the same boat. I have a factory assembled mk3 (long since upgraded to mk3s+/MMU2s) purchased in August 2018. I have had 5 magnets fall off in rapid succession over the past 2 days (Jan 24, 2021). FYI, no impacts caused them to be knocked loose. I have printed lots and lots of PLA/PETG/ASA, but recently only PLA (60C bed). I was surprised at how quickly it seems to have deteriorated.

I have some JB Weld around, I'll try that when my current print is done, then cover them with kapton tape. Hopefully none of the magnets will break in the interim (they seem to hold in place as long as the steel sheet is in place). It would be nice to see an official reply by a Prusa employee in this thread, and/or a help support article on this issue.

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

Whilst it's already been mentioned by Chuck, I also can confirm that JB Weld works great for fixing heat bed magnets in position. Use a little bit of adhesive then push the magnet home and pop some tape in place to hold the magnet whilst the adhesive cures. Jobs a good'un and the magnet should stay in place even when frequently heating the bed to high temperatures.