3D printed magnet hold downs with engraved cover

[timrsc]

3D printed magnet hold downs with engraved cover.

The original is here

3D Printed Neodymium Magnet Material Hold Down

I have been using magnets to hold down my various materials since I got the . There are plenty of topics from users who came up with solutions for this, and in addition to magnets, I’m a huge fan of the honeycomb bed hold down pins. Examples: New Material Holder Magnet Management Honeycomb Bed Hold Down Pins Simple Material Holder I had been covering my magnets with tape so that I had something to grab onto to pull off, but sometimes the magnets snapped to each other making it di…

But I used this derivative design which adds some nice hold down ledges on the side plus finger grips:

'Corrected' square GF Magnet hold-downs

Here are updated versions of square magnet holders that I had started a while ago; thanks to Pubultrastar for the inspiration to complete them. As others have reported, 3D Printed Neodymium Magnet Material Hold Down holders were scaled incorrectly when they downloaded the files, so I finally finished mine . [IMG_0370] These work on the GF and my PrusaMK3 3D printer. The Wood overlay top is in several layers so you can decide to Cut / Score / Engrave as you wish. Notches…

[cynd11]

Nice! I’ve got some of those from @pubultrastar (thanks again!); I put my own logo on them.

[timrsc]

I created a smaller version too.

Small magnet: 3/4" diameter x 1/16" thickness
Large magnet: 1.26" diameter x 1/16" thickness

I modified the original svg because I was seeing an enclosed perimiter on the squares rather than a single line. Here are both of the svg files. To print the smaller 3D printed part just scale the stl to 59.53% (x and y axis only!)

I will probably go one smaller for completeness… paper holddowns.

[timrsc]

And then there were three…

[lamachine.geo]

I made the 3d printed part. I have a cheap printer, so need to experiment with scale on the slicing software, 102% but your mileage may vary. Tops are next on (my nearly endless) list!

[randy.cohen]

It turns out, this doesn’t work so well. The air assist fan that hangs down from under the printhead is speed-regulated by the GF, it’s got a tachometer signal to say how fast it’s turning. When the fan passes over a strong magnet, it slows it down and the GF sees that as an air assist fault and it stops the print. Doesn’t happen every time, at least not in my experience, but it does happen. I think back when this thread was originally posted, the GF wasn’t checking the fan speed, or maybe it had a wider tolerance range, so it wasn’t a problem then.

I still use magnets, but only if I can place them in locations I am sure the print head won’t pass over.

[timrsc]

This is correct. I used to use magnets as hold downs all the time. Then they updated the software and every print would fail. Switched to T pins.

[MyDogsThinkImCrazy]

I still go strong and all in with magnets. Never had an issue. I used ceramic magnets only though. Most the time, I have about 6 in the bed holding down fabric to my magnetic whiteboard. Never been an issue

[MyDogsThinkImCrazy]

It’s a know issue for rare earth or neo magnets which have a BHmax of 30-45. I used ceramic which has closer to 3.5.

I have been using them for years and still do daily. Never an issue for ceramic and I never needed more then that.

[shop]

you have to use magnets properly to avoid the air assist fan issues. if you can diffuse/dissipate the magnetism on the top side, they have absolutely zero effect on the air assist fan. i’ve been using very powerful hard drive magnets since 2017 and have never had an issue. i use them anywhere and everywhere on the bed.

they work because they still have the metal plate attached to one side. if i flip them upside down, they don’t even slightly stick to the honeycomb or the bottom of the GF.

you can generally buy them very cheap on ebay or etsy. just make sure you buy the magnets from 3.5" HDDs, not laptop 2.5" HDDs. the smaller ones really aren’t that strong.

a couple of examples:

18 pcs Neodymium Magnets flat Strong Rare Earth hard drive Magnet. | eBay

8 pcs Neodymium Magnets flat Strong Rare Earth hard drive Magnet. | eBay

[randy.cohen]

I worked in the HDD business for a couple of decades before I switched to SSDs. I’ve got magnets that will pull the fillings out of your teeth. “Flux Plate” is what those metal plates are. Function similarly to a “Flux Ring” on a motor. Redirects the stray field on the back of the magnet, reducing how much field is emitted from that side and increasing the field strength on the front side.

Never thought to try them. Will give it a shot next time I need something held down.

[shop]

good to know what they’re called. yeah, they work fantastic for the GF.

[MyDogsThinkImCrazy]

I think you might be overthinking stuff. Ceramics work just fine. Nothing wrong with using something well in the design range.

[randy.cohen]

“Overthinking” is something I’ve never been accused of doing. I’m more of a “shoot from the hip” type. The old “measure twice, cut once” adage doesn’t constrain me because I live about 5 minutes away from a Home Depot. I’m more of an “eye ball it, and if it turns out wrong go buy another” kind of guy… (though I have learned to go high on my estimates so I can trim the piece down until it fits).

[MyDogsThinkImCrazy]

I applaud your recognition to now be well sounded in your stance of magnets.

That is a fine way to go about the GF. Just didn’t want it to appears as magnets are an issue if the approach was more shoot from the hip. Again, no issue for your style. Just don’t want to give proper use of magnets a bad name.