mgunlogson

It does work. Just not very well. Not enough to be widely usable.

If it was an idea it wouldn't have thousands of lines of code and working binaries.

100% infill doesn't remotely solve the problem I'm referring to. I'd ask you not jump to conclusions if you aren't experienced with 3D printing.

Printing 100% infill also wastes a ton of time and material on the interior of the part for nothing. I added a "dual infill shell" feature where you can use a light, fast infill for the interior of the part.

> It wouldn't give you prints that are stronger than those printed with 100% infill even if worked.

This is very speculative and I doubt accurate. Even 100% infill parts are 10X more brittle than injection molded ones and around half the strength. All because of z layer bonding weakness

Yes. It's a modified triangle infill pattern.

A solver pairs the triangle with one of its neighbors. Then cuts a window at the bottom during the slice. So plastic gets injected into the top of a triangle tube and flows through the window at the bottom of the U to its neighbor cell.

Download the binaries and try slicing with magma infill type. Turn off visibility of all the other line types and you'll see how it works

Thank you!

A lot of people here took issue with the crappy docs. My mistake, I barely spent any time on them.

The reason this "came out of nowhere" is because I was working on it in secret for a long time. So that patent trolls couldn't screw the 3DP community yet again.

because the plastic has to displace air.

This method seals the nozzle against the tube and injects under pressure (theoretically). And leaves a path for air to escape. Pretty much a micro version of injection molding

Z layer weakness is the main reason that 3d printed parts are brittle and much weaker than injected molded ones.

This is meant to knit together the part in the Z axis

You can set the tube height to like 4mm and that's pretty much what you'll get.

The tubes only need to be tall enough for a "window" at the bottom and a splitter in the middle so that plastic will flow up one side and down the other.

The window height calculations are automatic right now. To make sure the window area is as large as the tubes so it doesn't create a bottleneck that stops flow.

But if you print tiny tubes with a tiny nozzle you could probably get the tube height down to ~3mm.

There's binaries if you want to play with the settings and see it for yourself

> Will this pressure could cause the walls to delaminate from each other or deform?

Nobody knows :) . Give it a try!

> You're also parking the nozzle at the injection points, which will cause a lot of uneven cooling at the surface as well.

There's an "injection fan speed" setting that should probably be kept at 100%.

I'm not sure the "not have any cooling" will be a problem in practice. Because unlike normal printing you're not concentrating all the heat on one layer. It's going down Z dozens-hundreds of layers to already cooled areas of the part printed minutes ago. And the design tries to avoid having nearby tubes end on the same Z. So the area directly adjacent to the tube has probably been cooling for a while.

> 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.

No one knows. And I can't test it anymore. The code is done and I have other projects to work on. I've done probably a hundred test prints on my POS Ender 3. I need testers with better hardware. No matter what I try the top of the cell gets melty. This could be the low flow rate of my hotend (limits injection speed), the fairly bad cooling, or maybe something fancier like dual material is needed. Or maybe I just haven't landed on a good combination of settings since there's dozens of them.

I particularly want someone with dual nozzle to test so they can try injecting a low melting plastic like PLA into a heat resistant shell like CF-Nylon or more exotic materials. There's printer plastics that aren't even at glass transition temp when PLA is at printing temperature.

I added dual nozzle and multi material support. Obviously hasn't been tested though

Resin would be very interesting. The tube design seals them everywhere below the top layer. And the two ends of the tube tops are always at the same Z.

You could technically inject anything liquid enough into the tubes. Grout, resin, glue, silicone.

I did some basic calculations on isotropic heat loss in a circular tube. I don't have the knowledge to model it in detail but I don't think this is correct.

You can set tube height to something tiny like 5mm. It takes a fraction of a second to fill that.

As someone who's printed a lot, on fast printers you have to set a minimum layer time because it takes up to 20 seconds for the layer below to solidify, cool to below the glass transition. Plastic is a bad conductor so heat loss through the walls probably isn't as bad as you'd think

It's more than that.

I added a SAT solver to refine the tube endpoints so that nearby tubes don't start or end on the same layers. Even the default greedy solver (CP-SAT is SLOW) does a pretty good job at "staggering" the tube ends.

The part is "knitted" together in 3D at different Z layers.

Try the binaries. They've only been tested in Linux but they build fine for all platforms.

Slice something with MAGMA infill turned on and flip off the visibility of everything but injection lines. You'll see how the U shaped tubes knit the part together

The post was from a week ago. Must have been refreshed by the algo (or admins) for more visibility. Originally never got any comments.

Have you looked at the code or tried the binaries? I can assure you it very much exists as described.

Maybe I should have spent more time on the docs. I had LLM write some of the settings pages and other boring stuff.

> The problem that the author is describing is that the plastic is actually far too hot when injected and causes wall collapse. This is because the author isn't taking into account that FDM walls don't handle the required pressure near/above glass-transition points.

Yes exactly. And it may be a solved problem.

I need someone with a dual nozzle printer to try injecting something like PLA in a CF-Nylon part. I anticipated this and added support for dual nozzle and multi-material with a different material selectible for the injected channels. But be warned, it hasn't been tested it at all.

The filament is injected into tiny triangular U shaped channels, about twice as wide as the filament diameter. The depth of the channels is configurable and you can go as shallow as ~4mm. If you inject at a high rate that's not nearly enough time for the filament to cool off.

I actually had the opposite problem in testing. Plastic has bad thermal conductivity and the large volume of plastic in the channel was melting the top of the cell. That's why I asked for testers with dual nozzle printers. So they could try injecting a low melting point material into the channel while printing the rest of the part with something like Polycarbonate or CF-Nylon.

Some of the docs were written by LLM because writing docs is boring. Did you look at the code or try the binaries?

> Reading any of the research on that should make it obvious that you can't "inject" molten plastic into larger cavities, though.

There is quite a bit of research on injection molding. The pressure at the tip of a regular 3DP nozzle is around 200psi. That's actually high enough to inject a reasonably large cavity.