A Moineau pump based paste extruder.
suited for printing different pastes.
The moineau design has been tested with chocolat. For this model: wax, ceramic clay and moldable plastic will be possible aswell.
for the actual printing of chocolate a double walled part/module will be prefered to allow heating of the parts. (or use a resistance wire with an attached temperature controler)
Edit: the rotor and Oldham-Midle will be re-dimensiond to allow a smoother functioning when printed with a lower resolution.
This paste extruder printhead is inspired on the Moineau extruder thingy from Ttsalo and redesigned for use with other pastes than chocolate.
(where cleansing with boiling water is not possible)
It is a modular design so feel free to edit any module to adjust these to the paste you want to use it for. and will save costs if a part needs to be replaced due to wear & tear, or due to an unsuccesfull cleaning of a used paste. Especially the stuts and mountbase will require an other design for fitting on different printers: the mounting points on the inlet part are intended to be used for different adapters (in this case studs) to allow the fitting on different printers.
The parts are printed using a Dimension 1200ES, which allow for small spacings between the rotor and stator 0,245mm. printers with a lower accuracy may need a larger spacing.
For the assembly 35 M3x10 bolts are needed with M3 nuts.
(the same as are used for attaching the Stepper engine.
The insert is designed to allow the material to be pushed in with the aid of a plunger.
If u use the Repman based foot a threaded rod is required to use for the action of the z-axis switch (the foot is made as the standard bolt tends to miss the z axis on rare occasions causing problems.
As you might notice the stepper-motorshaft hole has a flatened edge.
this is done as the axis of our stepper engine has a side filed of to increase grip and avoid the snapping of a clamped part design.
THe use of pressurized air is not (yet) possible: the printed parts tend to be semi-permeable and let water and air run through "solid" walls.
a surface coating or impregnation could solve this problem but has not yet been tested.
.ipt parts will be added later to ease re-design and creation of additonal modules.
The O-ring grooves are designed for 22mm x 2.5 mm O rings but near similar sizes can be used aswell.