Foam Printing[edit | edit source]
This is a quick-and-dirty attempt to print foam using pressure-canned PU, commonly available in hardware stores.
Canned foam is used in building industry to seal insulation around doors and windows and such. Foam comes in a variety of types. Basic model expands a lot after spraying (200%?) and hardens. Some types remain elastic.
Obvious applications for foam printing are custom packaging and structures that need material attributes of the foams. For example, RF fields are absorbed by dense materials, airy PU may be usable as constructing unintrusive structures for RF measurements.
Initial prototype will use commercial metal tool, clamped on to a control motor.
Tips received from professionals:
- Foam tends to dry and lose stickiness. This could affect FDM printing so that layers wouldn't stick. A workaround for this is to spray water on the foam to delay the drying of the surface.
- Foam sticks everywhere and will clog the nozzle. Nozzles will be single-use or can be flushed with a cleaning fluid.
- Foam hardens faster when heated. Consider adding heat blower or IR heater. Heated bed will not likely be enough.
Project Status[edit | edit source]
- Building the delta printer, 80% done 13.4.2018
- Designing foam extruder prototype, measurements taken, playing around in OpenSCAD. 20% done 13.4.2018
- Test extruding foam manually. Waiting for weather to warm to be able to do it outside.
- Latest Hexagon AO hot-end doesn't fit the printed end-effector part, even with "considerable force". Ordering the correct model. Todo: adapt design for Hexagon AO, print, glue magnets and try out..
- Bought wrong number of slide bearings. Ordering more.
- Melzi 2.0 is impossible to find. Everyone who tells you they have it, actually sells you overpriced ebay-clone of Melzi 1.0.
- Peltiers for vacuum hot-end. Push heat to nozzle, cold to frame? Net-effect is heating anyway.
- Printing materials for space: how about glass? Glass objects are difficult to launch intact. The material is amorphous, thus plausible to print?