hello all. I work as a researcher in a rocket propulsion lab.

hello all. I work as a researcher in a rocket propulsion lab. In order to make paraffin fuel grains for hybrid rocket engines I was wondering if there exists 3D printers that print paraffin?

None that I’m aware of currently. Maybe you could develop the technology. There have been experiments, but nothing solidified.

I’m going to look into it next year. Thanks for the info

PLA burns away clean for making lost wax molds… Would you consider constructing a hybrid from PLA? I was actually just discussing this with @Jake_Guepe , PLA with NOX, coat the PLA with carbon fiber resin after printing.

@Paul_Chase I don’t think this is for lost wax. If you notice, he says “paraffin fuel grains” - this is actually fuel as far as I’m aware. For a hybrid rocket engine.

Yes, Anthony. PLA as fuel in a hybrid rocket engine. For a hybrid, you need something that burns in the presence of oxygen (or nitrous oxide for the cheapies). Fortunately, almost /anything/ will burn when you pass oxygen over it :slight_smile:

Makes sense I guess. PLA is an oil afterall. I’d love to see someone attempt this and document it. We’re doing hybrid rockets @ our lab.

I’ve seen videos of ABS burning pretty violently, so you might also try that as a possible alternative to paraffin (just don’t breath the fumes).

it could certainly be done.
maybe look into the chocolate or ceramic ie paste extrudes stick that on any reprap and you’re good to go.
might want to maybe chill the build plate instead of heating it…

you could even mix anything you like into the paraffin as long as it was paste at temperature.

course you’d have to watch fire (and explosive?) hazard. make sure the whole setup is in a safe place. but if you’re messing with that stuff you know this already :-p

You may need to design an extruder for the softer material but I see no reason why existing hot ends would not work at 60 or 80 degrees Celsius.

the chocolate one should work perfect.

But the pneumatic valves cost a fortune.

I don’t know if it’s ever been built but the reprap wiki has a page on some sort of wax vacuum. Basically a hot tube to act as a milling head for wax, and suction takes the melted wax away.

You don’t want to heat wax to mill it. You want to cool it to get any reasonable surface finish.

@Marcus_Wolschon , what @Nick_Parker is talking about is a cooled piece of wax, with a very hot needle tip. As the needle tip passes through the wax, it sucks it up. The heat is acting as part of the tool. The rest of the wax is cooled down. Benefit being you don’t have wax chips all over the place. :slight_smile: