How to safely insert magnets into a print?
Hello,
I plan to print the following model and want to use the "pause at layer" feature to insert some neodym magnets in those holes, while the printer is pausing. The holes are 10.5 x 4mm to fit 10x3mm magnets. Is there anything to consider?
I am worried about:
- the magnets not fitting easily, don't want to have to push them in risking the model lifting from bed.
- the magnets clinging to the nozzle, while the solid layers above the magnets are being printed. Will the magnets jump out of the holes?
The magnets will be fully enclosed in the print.
Best Answer by TeachThePrints:
Found working parameters.
a) keep the bottomlayers thin, the magnets will want to stick to the magnetic bed countering the upward pull to the heatblock.
b) diamater of 10.1 or 10.2 are large enough to push the magnets easily in, while still ensuring enough of a press-fit to hold the magnets in.
With these settings, i can repeatedly move the extruder right over the magnets without having them jump to the heatblock.
Prusa Mini FW6.2.4
RE: How to safely insert magnets into a print?
Enlarge the holes. I used a drill bit.
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Chuck H
3D Printer Review Blog
RE: How to safely insert magnets into a print?
@cwbullet
It's a model I am making, so any dimensions are adjustable. No need to drill anything.
What I don't know however is, what the recommended size of those holes are.
I've printed models with press-fit holes before, where the magnets were inserted after the print finished. I'd use a wrench to push the magnets in. This probably won't be possible midprint without disturbing the print adhesion, so the holes will have be larger than the magnets. However, is there a too large hole?
Prusa Mini FW6.2.4
RE: How to safely insert magnets into a print?
@teachtheprints
Not if the magnet is buried. Too large of a hole would only be an issue the magnet drops out,
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Chuck H
3D Printer Review Blog
RE: How to safely insert magnets into a print?
I might suggest making a small test print. I do this often for parts that have to fit together precisely.
If I were making a cavity for a 3mm (diameter) magnet, I would first measure the magnets with a good digital caliper to get the exact dimension and then make the hole maybe .1-.2mm (diameter) larger and do a test print for that. When you get down to fractional millimeters, things like the width of the extrusion become significant, and I've found that test printing is a good way to see what works and to tweak the dimensions for the best fit. I would want to get it to the point that the magnet requires a gentle push to get it in, but not enough that the plastic part will deform when inserting.
I like to have parts which fit together well, and I've found that test prints are very time-effective in doing that.
RE: How to safely insert magnets into a print?
There seems to be an issue, where the magnets are attracted to the heatblock. I've tested brass & steel nozzles, they don't make a difference. Even when the magnet is half a cm lower than the nozzle, it will get pulled up and cling to the heatblock. Do you guys glue the magnets in and wait long enough for the glue to dry before continuing the print?
Prusa Mini FW6.2.4
RE: How to safely insert magnets into a print?
Found working parameters.
a) keep the bottomlayers thin, the magnets will want to stick to the magnetic bed countering the upward pull to the heatblock.
b) diamater of 10.1 or 10.2 are large enough to push the magnets easily in, while still ensuring enough of a press-fit to hold the magnets in.
With these settings, i can repeatedly move the extruder right over the magnets without having them jump to the heatblock.
Prusa Mini FW6.2.4
RE: How to safely insert magnets into a print?
Print yourself a 1mm high cap fitting on top of the magnet in the hole first. Insert the magnet, press the cap on top, flush to the surrounding surface, and the magnet won´t jump.
I try to give answers to the best of my ability, but I am not a 3D printing pro by any means, and anything you do you do at your own risk. BTW: I have no food for…
RE: How to safely insert magnets into a print?
I've done prints like this tons of times. Never had a problem with the magnets getting "sucked out".
Just use a drop of CA glue then spray on CA activator and the glue dries instantly.
Oh and make sure the hole is a bit oversized so that the magnet drops in freely.
- Pause print.
- Add small drop of CA in the hole.
- Drop in the magnet.
- Add a squirt of activator.
- Resume Print.
This trick works even if the magnets are added to parts of the print which is far from the print bed.
My printers: Mk3s / Mk3s clone with +upgrdaes (you know SPinda and all that good stuff) / Mini+ / Ender 3 v2
RE: How to safely insert magnets into a print?
Yeah exactly what I would do. Just add a drop of CA glue in the hole and the magnet will stay put until its covered by the layers above.
Original Prusa Mini + Smooth PEI
Prusa Slicer 2.6.0
RE: How to safely insert magnets into a print?
Heater block is from aluminum and standard nozzle is brass. But screws holding heater cartridge or thermistor are from steel and may or may not be magnetic. Steel nozzle will also attract magnets.
RE: How to safely insert magnets into a print?
I feel pretty dumb not being able to figure this out.
I have an object that I've modeled in Rhino and I'd like to embed magnets just below the surface (.3mm) of said object. When I place the volumes representing the magnets below the surface, I'm obviously unable to boolean difference the volumes out of my model because they don't actually intersect.
So how are people embedding magnets and covering over them in their print?
I tried modeling a simple cube and then placing a pyramid inside of it. When I brought it into PrusaSlicer the pyramid is not recognized. I exported the cube with pyramid inside and a pyramid next to it at the same height so it'd be apparent when sliced that it's not showing up.
Any help would be greatly appreciated!
RE: How to safely insert magnets into a print?
This post is really old.
RE: How to safely insert magnets into a print?
I'm hoping to send a message to one of the original posters...
RE: How to safely insert magnets into a print?
...but it appears I need to have so many posts under my belt first.
RE: How to safely insert magnets into a print?
I wonder if a captcha method or similar...
RE: How to safely insert magnets into a print?
might be a better way to block bots, but let people reach out to seek help via the forums, in what I would suppose is part of the original goal of said forums.
RE: How to safely insert magnets into a print?
Maybe these posts came through in too rapid of succession, thus foiling my attempt to get a certain number of posts so I could message a member. Drat.
RE: How to safely insert magnets into a print?
To answer your question of how many people are able to "just add holes" for magnets, it's very easy to add negative volumes in the slicer itself. Right-click on the model listing, click Add Negative Volume, select cylinder. Make sure you add enough tolerance for your magnet size, place accordingly, and then just make sure you have the pause set at the first solid layer above the hole.
As to why you're unable to add the voids within Rhino and have it show up in the slicer, I'm guessing it's some quirk of Rhino optimizing the mesh to ignore internal voids. What you might try doing is having one model export for the actual model, and then a separate model export for your negative volume. Load the main model into the slicer, and then Add Negative Volume, but instead select Load... and pick your negative model. If you're lucky, it'll even stay aligned and not need any fiddling to get into place.