Enclosing foreign objects in the print

Hello, I am new here, ordered a portabee and it is on its way, been thinking of all kinds of things to make and can't wait.

I have some neodymium magnets, which are very strong, but brittle, and if allowed to snap together or to a surface too forcefully they chip or break.
One of my ideas was to print a hollow cuboid to put them in so that they have a protective plastic casing completely around them.
My question is, can I just send a hollow cuboid to print, and then once it is about to print the top layer, pause the print and put the magnet in, then let it print the last layer, thus fully enclosing the magnet?
I know that I could just print out a box and lid seperately then glue it together with acetone slurry or superglue, but I'm more interested in the concept as this could be used for doing other things aswell, (plastic parts reinforced with metal inside them?)
Seems like a good thing to try, not sure if anyone else has done this before.

... of course, you can do this ... was done with paste-dispensers and different materials like conducting paste and silicone for '3d-circuits' ... or different coloured edible pastes ...

I think you have to paint the top surface of the magnet with some agent for better adhesion of the filament - either some ABS solved in Acetone, or more 'friendly' mixtures like sugar-water or beer ... or hair-spray ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Thanks for the advice, So it has been done before...
I would need to pause the print on exactly the right layer, because too little, and the top of the magnet will be higher than the bottom of the extruder, and possibly the extruder will run into it, because it isn't expecting it to be there. Too high and it will start to bridge the top, and then I won't be able to put the magnet in.
How do I make the printer pause at exactly the right time?

AFAIK this can be done best with G-Code simulation, where you identify manually the questioned layer and insert a "WAIT" macro or function.after this line.

I'm sometimes doing this for CNC-milling or laser-sintering -- but with the programs and postprocessors for my system, what's different from RepRap behaviour ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

I've done this a few times with various objects (like batteries: [www.thingiverse.com]) A useful trick is making the height of the void a fraction larger than the height of the object. That way you don't bash the nozzle, and the first few bridging layers sag a bit until they rest on the object, stopping it from rattling, but then after a few layers the surface flattens out. I think the main problem you could have is that neodymium magnets really don't like getting hot - if you're printing abs then the heated bed might demagnetise them. pla is probably safer, but you might be fine as long as you just cool the part down reasonably quickly.

Just a side note: if you just pause over the print with some noozles, they leave an ugly blob due to oozing. You might want to add some gcode to move the noozle away and return it after you resume.
The most simple way for me was to add a dummy column object on the plate, that gets printed in parallel. It has a marking where the print should be paused - for example a square column with a circle final layer, where I must pause.

As James noted, demagnetization could be an issue in certain cases. Of course, if you do encounter that issue, you could print two mating parts and then glue them together to encapsulate an object like a neodynium magnet

Edited 1 time(s). Last edit at 02/19/2013 12:31PM by xiando.

The curie point for neomydium magnets is like 320C, I don't think there will be a problem with demagnetisation.

Have you tried Cura? There is a plugin that does the 'pause and move head away' as you slice.