Transporting true hot pipes

The extruding part have to be hot for pumping to extrusion, in order to avoid wax to cool and solidify.

So I have 3 pipes : 1 carrying the melted wax, one for hot liquid  – water for first tests – coming from the pump, and one for liquid returning to the hot tank.

At first, I imagined hot pipe wounded around wax pipe and the third pipe next to the others. But the heat transfer will be harzardable and.. pretty uggly !

I decided to design a more complex but beautiful carrying all pipes into the hot pipe from pump. That way, we’ve got a single pipe and thermal transfer is perfect, included smaller heat dissipation because the returning pipe is also heaten.

Design

The principle

In one hand, the wax is meltedand pumped with precision through a pipe to be deposited with a 0,2mm nozzle.

In the other hand, the entire piping is warmed by a second circuit, with hot water if wax melts under 90°C. The water is pumped with Drinted – forget the uggly « 3D printed »… please ! – with Drinted piston pump driven by a DC motor. You’ll see my first attempts will be easy for ALL to craft, and it’s the only purpose ! (So please, keep me away from « poor guys crafted » thing… it’s all the way I like to design ! Craft from nothing is good !)

The head

I made the head into a M10 rod, normal steel NOT Stainless steel. Stainless steel is not a good heat conductor. To avoid rusting, I have the absolute trick : the carcinogenic Phosphoric Acid from your coke 😉 (I did restore several fuel tank with that !) or phosphoric acid rated at 75% if you can buy it. A very small amount will keep any steel and iron away from rust. WaXeM will probably use glycol to allow 125°C, and this does not cause any corrosion.

The pipe is directly connected at the stop, and will feed the extrusion.

At the bottom, I use a brass nozzle taken from another hot end, with M6 connection. The nozzle is easy to drill with 0,2mm, easier that steel.

I will show you the entire process to craft it, the tricky part is how to drill in axis.

Piping

there is two keys to assemble and separate pipes : the carriage flowing and nozzle feeding and the pumps connection.  so I designed the most simple parts that I can ! here you ave 3D view of carriage, pumps end box and also a simple schematic :

WaXeM Carriage
by jpabraham
on Sketchfab

Separing pipes
by jpabraham
on Sketchfab