linear direct 3d printer extruder drive. fusion 360.

Designed to directly replace NEMA17 in any 3D printer, high force-to-weight ratio, high continuous force and peak force weight 4. 2oz (119 grams)
My Pusa I3 and almost all 3D printers use the Scotch Yoke mechan extruder with high acceleration Halbach array magnetic system with stepping motors.
I decided to develop a 3-based-
Phase Linear actuator with magnetic Halbach array.
It is designed to replace NEMA17 directly in any 3D printer.
It\'s usually a linear drive (
Like VCA or similar)
Metal parts are required, so I focus on the applicability of 3D printing with minimal metal parts.
Such driving can be carried out almost at home.
The weight of the device is 119 grams, that is, almost 2 grams.
5 times easier than the NEMA17 used in my Prusa i3.
This drive needs 3-
An ARM microprocessor and a phase PWM driver.
The driving seat matches the NEMA17 31mm square and M3 screws.
The Assembly of the whole unit is also in the back of the M3 screw.
The shaft of the optical encoder is located in the same place.
Like any motor, this drive is run on the basis of the Lorenzo force equation.
After simplification, this force is directly proportional to the current strength, conductor length, magnetic field induction, and the sine of the angle between the induction vector and the conductor.
Halbach arrays were applied to increase the magnetic flux.
This will increase the magnetic flux from the conductor and reduce the magnetic flux on another non-conductorworking side.
No background required for Halbach array
The iron behind the magnetic system, which is good for the weight parameters of the equipment.
I made drawings and animations of all the operating principles in Fusion 360.
As can be seen from the video, the linear motion of the magnetic assembly is converted into circular motion using the Scottish coil.
This is a very simple and reliable solution to use in many devices.
The main body of the driver, as well as the brackets of the Halbach array and the details of the Scottish coil mechanism, are all made using a 3D printing method.
In addition, we use 3 625ZZ bearings and 2mm X 10mm pins as Scottish coils.
Magnets are an important part of the design.
We need 5 5X25mm N42 rare earth magnets. You can use composite magnets, they need 10 pieces.
The D5x 30mm, copper wire awg28 coil is wound around the 3d printing base.
The cross section of each coil is 4mm x 6mm.
After winding, wrap the coil around the coil with PTFE tape.
Two coils are formed in the auxiliary part, resulting in nested coils.
After forming, all coils are located in the groove of the housing.
The Assembly of the magnetic system is very simple, following the direction of the polarity of the magnet.
\"North-
It doesn\'t matter \"south\", the electronic driver will switch the original polarity of the coil to the desired direction.
Scotch yoke also has no difficulty in assembly, but the shaft of the gear and encoder must be firmly fixed.
To do this, apply the adhesive when assembling.
Next, we collect the equipment completely.
When rotating the shaft with your finger, there should be no mechanical resistance.
Otherwise, it is necessary to grind the surface where the magnetic system slides.
As an electronic driver, any 3-
Phase drives with optical feedback can be used.
It should be designed to have a current of at least 15 am times per phase and a voltage of 12 volts.
All the files are listed here. Filament ABS.
Do not use PLA and similar materials, as the drive coil is heated to about 60 degrees, which may result in deformation and wedges of the entire structure of the extruder.