Oil Bath

I was sitting here minding my own business when a thought struck me. I took a small piece of both HDPE and UHMWPE into the kitchen and dropped them into cooking oil. both sank extremely slowly. When I repeated this with dimethicone instead of cooking oil, the HDPE was actually buoyant. The UHMWPE still sank but just barely.

Why was I doing this? It occurred to me that, if you had a liquid bath of roughly the same density as your build material, a support material becomes unnecessary. You could also draw lines in 3-space (i.e. all 3 axes moving at once), rather than just on an XY plane.

Of course, extruding plastic in an oil bath introduces all sorts of logistical problems: anchoring, heat dissipation, general messiness. Probably causes more problems than it's worth, really.

Still, if and when I get my machine built, I might have to try it, just once.

Steve,

That's an interesting idea. Has anything like that been done before? I mean to ask, will you have to completely invent a new process or can you use previous work?

Demented

Hmm, can't tell if anyone's done this before. The closest I could find was a selective curing process where the liquid medium is also the build material.

... most liquid-curing RP-systems activate the surface of the liquid epoxy through an UV-laser or LCD-beamer-focus, so you build slices on slices as normal - but you have to build supports too, or your hardening parts would crumble, if you move the basis-platform in the bath and move the washer to make the surface plain after overfilling ...

I had similar thoughts - when the curing area would be a small point directly before a tool-tip (laser-head or high-frequency-microantenna for heat-curing), then i could flood the working area completely and move the curing-spot 3-dimensional inside the liquid to make a free form.

But i have to build supports too, if through turbulences while moving the builded structure would be waving ...

Viktor

At the very least, doing that might increase the angle you can build at. For example you could probably build an upside-down top-hat shape.

Whether it's worth the limitations in building materials is another question though.

Interesting, although there doesnt seem any reason to stick to solely support materials. You could make the bath a polyol and then extrude liquid hardener into it, making a quick and dirty (and I mean really DIRTY) protoyper with no need for support mateial and the ability to build in X Y and Z at the same time.

Mike

The views expressed in this post is not that of my employer. Attempts at implimenation are at your own risk.

Mike I thought along the same lines as you.

having a vat with the cheap catalyzer I'm developing and printing Furfuryl Alcohol or Furfural threads on top of it, then dropping the layer a level. it would make for a ruff prototyper if we can solve the problem of enclosed volumes in the 3D models.

It's like a SLA (stereo lythography) but without lasers.