Better 3D Printing Overhangs? Dive! Dive!

If you want better 3D-printed overhangs, you need better cooling, right? What would be better for cooling than printing submerged in water? It turns out [CPSdrone] tried it, and, at least for overhangs, it seems to work pretty well. Check it out in the video below.

Of course, there are some downsides. First, the parts of the 3D printer don’t want to work in water. The guys used deionized water to minimize water conductivity and also sealed open connections. Some components were replaced with equivalents that were less likely to corrode. However, the bearings in the stepper are still going to corrode at some point.

There’s no free lunch, though. Cooling is good for some parts of 3D printing. But for the hot parts, it could cool down too much. They encased the hot end in a large silicon block to help prevent this. They also potted the controller board, which works but makes future maintenance and upgrades painful. Initial tests looked promising.

They finally put the modified printer in a water tank and got some prints. Overhangs were good — especially extreme overhangs — but layer adhesion, as you might expect, suffers. They speculate that heating the water could help. However, the parts looked usable. There were a few trials along the way, but they solved all the problems, at least for a short time.

In the end, bridges didn’t look much better, and, as a side effect, the prints were full of water when they came off the bed. The next obvious test is to do the printing in a public swimming pool. It is doubtful that is any better, but it certainly makes a good conversation starter at the local pool.

We are a sucker for novel 3D printers. Of just anything that mixes unusual items with 3D printing.

28 thoughts on “Better 3D Printing Overhangs? Dive! Dive!

  1. “They encased the hot end in a large silicon block…”

    Silicone. Too tired and too irritated at yet another person who should know the difference to come up with anything witty.

  2. It’s not stupid. You might say “it won’t work”, but you won’t know until you try it and either prove that it does, or demonstrate that it doesn’t. Until then you can merely speculate.
    Sometimes a crazy idea gives spectacular new insight into something that we wouldn’t have had if the idea was dismissed. Even if something doesn’t work it’s good data, and the next guy can save time by not trying it, thus getting onto the next discovery sooner.

    1. Yeah, the fact that this works at all is in my opinion enough justification for having tried it out. Of course submerging the whole printer is probably more for youtube clicks than actual function, and any real implementation would just have a water container for the print volume.

      1. he should change it so that only the bed move in Z and most of the X/Y and print head is out of the water imho, a bit like resin printer works with the part barely submerged… reduces all the corrosion and heating losses…

        1. That’s what I was thinking. Print just at or below the water line.

          I flashed back to the 70’s when we made “water candles” by pouring molten wax into a container/base then slowly submerging it while simultaneously pouring more wax to keep a molten puddle going at the surface.

        1. That seems doable. PLA has a density of 1.25 g/cm3, water 1.00, and saturated brine 1.20g/m3. So adding salt to the water will make the water approach the density of PLA. But brine would cause corrosion. A Delta printer might actually be more resistant as only the head would have to be covered.

    1. As soon as i saw this idea I thought the same thing. It’s less thermally conductive than water so the printed parts are stronger, non corrosive, abd electrically insulative so the printer doesn’t need to be sealed. Perhaps the concern was some oil getting stuck between layers and affecting adhesion? Or perhaps mineral oil is too dense and the filament would want to float instead of droop, inverting the problem this was meant to fix.

  3. Would be interesting to do it with a Voron 2 instead. Put the electronics on top and use a pump and tank to keep the water level at the current Z-height.

    Would remove all electronics from the water and hopefully increase layer adhesion while retaining the benefit of using the water as support.

    1. But you don’t want thermal conductivity. You want that hot spot on the hotend not to dissipate far from where plastic is melted.

      In fact, they could have used powder instead of a liquid to limit conductivity. Wait a minute…

  4. If you are so worried about overhangs, just add layers of sand or other easy to take out fine material, like many other 3d printing methods do. It will also help with warping and many other problems
    I think at that point it would be easier to go this route that that one

  5. This is a cool concept but it isn’t well thought out. Most plastics warp or crack when cooled too fast, it’s not much of an issue with PLA but you can see it’s mechanical properties suffer here too.

    I doubt anyone would go through all this just to print decorative parts and any structural or functional parts will not do well with the lower layer adhesion and probably lots of internal stresses due to the rapid cooling.

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