Show HN: 3D print Z reinforcement via injected loops (mgunlogson.github.io)

20 points by mgunlogson 5 days ago

7 comments:

by slabity an hour ago

I've seen this technique a lot, but mostly as a post-processing technique where resin, fiber, or some other type of plastic is injected into the channels after printing is completed. It would be interesting to see this done during the normal printing process.

I am a little skeptical on the technique though. FDM printed walls are known to not handle pressure well, especially during printing when its past its glass-transition temperature. This process essentially uses the pressure from the extruder to inject a channel with molten plastic. Will this pressure could cause the walls to delaminate from each other or deform?

And how does this affect plastic that tends to warp significantly during printing? The molten plastic is injected into insulated channels that will not receive any active cooling. You're also parking the nozzle at the injection points, which will cause a lot of uneven cooling at the surface as well. For high-warping plastics like ABS, that could cause a lot of issues.

So I guess the underlying question should be, does this actually work? What is the measured difference in tension strength between parts printed normally vs with MAGMA infills? Specifically when using the same amount of plastic. There's no data or even pictures that indicate this is working.

by deckar01 15 minutes ago

When you say continuous interlocking U shape, are you saying it fills one channel from the top until the connected channel fills from the bottom?

by dwallin 2 hours ago

Instead of one large channel throughout the whole print, why not multiple small 2-4 layer bridges?

by gus_massa 5 days ago

Do you have a photos of objects you build with this? A video?

by mgunlogson 3 hours ago

No, unfortunately. I've printed a ton of objects but nothing clean enough to be interesting.

The top of cells always melt as I'm using the same material for injection and the rest of the print. Someone with a dual nozzle printer could try something like PLA injection in a polycarbonate part. I added support but don't have a printer capable of that.

It's also possible that different print settings would work. I'm releasing the features to the community as I've run out of patience with doing a hundred hours of test prints.

We need to crowd test the best settings and nozzles, materials, etc to make this work well

by coryrc 2 hours ago

Why do you think this is better than the old practice of filling straight holes a few layers deep?

by mgunlogson 5 days ago

Here for any questions about how it all works :).

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