Homebrew casting, 3D printing-with-Hexagon ideas

Roman_K2

(This branches off from the thread about the armored car-type military vehicle.)

Good idea about 3D printing. I haven't really looked at the stuff, or what's currently available, but I'm assuming that fairly durable materials and printed objects are within reach for for most serious hobbyists. I posted recently (early 2016) about this but my message generated zero comments so either we're off on a completely wrong track with this, or everyone else is either asleep or away from their computer!!!

I'm not real big on homebrew casting at the moment, although I am curious that plastic resin and molds are available again in my major center after an apparent abscence for several years. I think Pebeo is one of the manufacturers of that but I could be wrong.

When I did the molten aluminum thing in the 1970's it went like this: in the foundry room there was a smallish, cylindrical shaped furnace. It had a swinging door about the size of a beer can, that you could open to peek inside. The door was operated by a tool (or a set of tongs, I forget) that was at least 6 feet long and probably more like 7 or 8 feet. The heat ray that shot out from the opening was like something out of a movie. It resembled a reddish-orange laser beam and it stretched at least 20-25 feet across the room with no apparent dimishining in its strength or power.

Another process that makes durable stuff molds or small parts is ceramics, but those ovens go up to several hundred degrees if I'm not mistaken. I gave myself a nasty burn the other day with a couple of ounces hot water, let alone messing around with furnace-grade material ouch.

cdordoni

Casting can use molds that are single use, or reused.

In general, single use molds will give you parts that don't require draft angle or "pull" from the mold. The mold is destroyed to release the part, so the part can have almost any shape.

Molds that are reused will almost certainly require some draft angle to allow the part to easily release from the mold. This must be considered in the design of your part, as well as the
"parting line", when you have several mold sections that separate to release the part. The parting line can be a flat plane where mold sections come together. Generally this is preferred since it makes it easier to produce the mold.

However, some parts are better suited for a parting line that follows the contour of the part. A lot of cast or molded figures typically have parting lines that are not straight, to allow the figure to be more realistic.

Hexagon could be use to make a positive (or part the mold is generated from), or even the mold itself, with 3D printing. Unfortunately it does not have any molding specific tools, and will require some thought and care in modeling to provide proper draft if needed.