Building a wax extruder using Lost wax casting
I used my 3D printer and downloaded the extrusion screw that Siemen Cuypers designed and posted to Thingiverse. I then edited the file so it had a hollow center (better for metal casting) and a different base where I could machine in a keyed shaft into the base. I then printed it out at 5% infill in PLA with 2 layer walls. I made the screw 80 mm in diameter and almost 2 feet long to account for shrinkage and machining. Then glued the 3 parts of the screw together for the final size.
I coated the print in ceramic shell and via the lost wax method I poured and cast a bronze copy of the screw which is what you can see in the photos. For some reason I can only add 3 pictures in a post?
Anyway, the next step is to machine the sides of the screw so it will fit inside a 3 inch bored hydraulic cylinder (like the ones that power back hoe digger machine arms). Then I’ll connect it up to a 1/3 hp motor with a 20:1 gear reducer. I will have a variable speed controller on the machine and I have two PID temperature controllers to vary the temperature of the tube in two different regions. I bought band heaters to warm up the wax as it passes through the cylinder. I will cut different shapes into steel end caps. These will become dies for the wax to come out of. One thing I wonder if I will need is a breaker plate? Do you think a breaker plate is necessary or helpful in extruders? I see them on commercial units but I am not really sure what their purpose is or how necessary they really are at the hobby level.
Thanks. Yes the bearing has tapered walls so when it is pushed on at 90 degrees from the axis of the wheels it just forces the bearing further into the socket.
I’m packing up my car to drive back to my workshop now. I’ll start work on welding the frame for the extruder tomorrow or the next day.
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