N-35UH magnetic bed mod
April 12, 2020 08:42PM
Hi,

If anyone has any experience with this, what do you think of kapton taping 30 N-35UH high temperature neodymium 20x6x2 magnets under a 220x220 PCB/aluminum heated bed? Does anyone know if there will be enough holding force through 3mm of pcb and aluminum to hold a spring steel sheet down?

The Mk3S uses something similar but over a larger bed but also has a closer space between magnets and the spring steel. I am hoping going a little smaller in build volume will keep a sufficient holding force for cheap.

220x220 PCB/Aluminum bed, 95 peak temp = $10
30pcs magnets = $13
220x220 Spring steel sheet with one side PEI = $17

The extra $30 for a magnetic spring steel bed can be a bit pricy over 5-7 $200 printers so think it is good value? Idk if anyone can recommend a cheaper spring steel sheet or magnets.

Thanks
Re: N-35UH magnetic bed mod
April 13, 2020 12:21PM
I am honestly changing my mind to a 235x235mm heated bed that can reach 110 degrees celcius but it is also a bit of a monster with current draw at 9.2A.A RAMPS 1.6 can handle it especially with active cooling. It is all the more reason to avoid the cheap rubber magnetic pads and go with N-35UH magnets. What is a good way to ask this, can the Ender 3 bed be modded with magnets underneath?

Edited 1 time(s). Last edit at 04/13/2020 03:20PM by Power3DPrinting.
Re: N-35UH magnetic bed mod
April 16, 2020 07:05PM
Hi There,


I tried to use N52 magnets 3x14x24mm 12 pcs on a 215x215x5mm cast tooling plate. They supposedly lose magnetism at 130c.
There was magnetic effect holding my Spring plate to the heated bed, barely sufficient though.

The store adviced me the magnets will work for 3mm, no guarantee on thicker plates.

The weird thing was that after being heated a while the magnets did seem to lose magnetism and the side of the steel spring sheet would bend upwards, as if the magnetism got reversed and was pushing the plate away.

I glued the magnets to the plate using black silicon glue/grease.

The prices you mentioned are about as cheap as the items come.

Can the ender 3 bed be fitted with magnets under it? Yes, no problem. (i also own an ender 5)

Magnetic pads work well, i heard there are high tempature pads on the market, if you can find one i would definitely advice to use this instead of magnets.
Also, get a spring steel plate with Pei powder-coated , these used to be very expensive but can be found for a small extra price.
Re: N-35UH magnetic bed mod
April 18, 2020 06:49PM
Thanks a ton, that is all really good advice!
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