600 Watt, 3d-printed, Halbach Array, brushless DC electric Motor

hi how are you here is my most recent creation it's a 3d printed brushless motor this is not my first motor maybe you have seen in my other videos that I already constructed another model for make see based on that knowledge I've now created a fully redesigned version all the main parts are still 3d printed except magnets copper wires ball bearings and some screws the new motor is clearly larger much more powerful and also more efficient the larger forces require several design changes compared with the Mexi motor however the most interesting modification is the arrangement of the magnets as holdback array which I will explain in a few seconds let's first have a quick look at the performance the motor is connected to a 30 volt battery with a 20 inch propeller which draws 20 amps and rotates approximately with 6,500 rpm the system efficiency including the ESC is 80% in order to calculate this efficiency as measured the input voltage and current at the ESC the rotation speed and the torque at the motor let's now inspect the rotor it is 3d printed and has slots for fitting the magnets as initially mentioned the magnets are arranged as haulback array neighboring magnets are rotated by a 90-degree angle and after four magnets the pattern is repeated the effect is an Augmented magnetic field on one side of the array and a much weaker field on the other side if you want to learn more about the haulback array you can find a great article in Wikipedia the rotor has the stronger side of the array oriented inside towards the copper wires of the stator before creating the final rotor I've made this smaller version with some spare magnets in order to check the construction the magnetic field viewing film shows the orientation but not directly the force of the magnetic field compared with a regular arrangement of the magnets the field inside the rotor appears to be more extended than outside in contrast to a regular hole back array the section of the magnets in this motor are not square but rectangular maybe my array is a bit less effective but it helps to reduce the total weight the main magnets of the rotor are 40 millimeter long 4 millimeter thick and 10 millimeter wide the rotor has 18 poles and the diameter at the air gap is 81 millimeter the forces between the magnets push two smaller magnets radially against the outer wall of the rotor and the larger magnets are pushed towards the rotation axis because I couldn't find 40 millimeter long versions of the small magnets I replaced them by two shorter versions these are laterally repelling each other and as long as the rotor late isn't closed the magnets sometimes can slide out of place with such a large rotor made of 3d printed plastic it is not a good idea to support it only on one side the centrifugal forces could cause wobbling on the portage side for this reason the new design has an additional large ball bearing the screws for the stator mount and the copper wire connections are fed through that ball bearing the stator core has 54 slots for the copper wires like the Mexi motor it is also printed with magnetic PLA from proto pasta the ferromagnetic material reduces the rotation speed and increases the torque but I don't know how it effects efficiency maybe I will test that later the special designed headers at the side of the state the teeth are guiding the overcrossing copper wires and simplify the manual winding work the winding pattern is fairly simple after winding the first three coils the scheme becomes obvious there are variations possible with the number of turns and the wire cross-section this allows to adjust the nominal voltage to the desired application the four threaded rods not only clamp the two pieces of the stator mount together but they also serve as a reinforcement for lateral forces executed to the shaft finally these rods are used to mount the motor on a chassis the motor is a regular brushless DC motor and therefore the three wires can be connected with a regular ESC for more information how a brushless motor works I again recommend to browse Wikipedia [Music] the new design demonstrates that it is possible to scale a 3d printed motor to different levels of power actually I find it quite impressive that a motor mainly made of plastic can perform almost with one kilowatt with all that power it is possible to drive an e-bike a skateboard RC planes or cars or many other devices I hope you like to support me and my work and maybe you want to make your own copy of this motor for this reason I will be selling the STL files for a reasonable price I'll also provide a parts list for the required hardware like magnets ball bearings and copper wire with sources where to buy it and there will be detailed assembly instructions please check the links in the video description

Channel: Christoph Laimer

Views: 523,642

Rating: 4.9563813 out of 5

Keywords: 3d-printed, halbach, brushless, motor, dc, electric, diy, makesea, neodymium, ultimaker, makerbot, pla, magnetic pla, petg, replicator, laimer, christoph, proto-pasta

Id: NFvMC3l3fGY

Length: 6min 25sec (385 seconds)

Published: Wed May 03 2017

Reddit Comments

[u/lxo96]

I think Christoph is one of the best people of pushing the actual uses of FDM 3D prints.

[u/fear_the_future]

what an amazing print quality

[u/cediddi]

How smart would it be to use this motor with a nylon or metal reduction gears to turn a bike into a ebike.

[u/spap-oop]

I'd imagine that the coils will eventually warm up, which will deform the pla and lead to a rapid unexpected disassembly event.

Still, very impressive!

[u/EisMann85]

Currently printing an earlier version of this motor. It's very impressive. My plan is to scale this up and use it for slow speed power generation.

[u/freelyread]

Christoph, that is amazing. Absolutely terrific work. Thanks for sharing this and for making your work available to others.

1 Kilowatt, this engines power, is about 1.3 Horsepower. For example, a powerful kitchen mixer.

[u/ShadowRam]

Pretty amazing,

IMO, $10 is a pretty reasonable price for a design like this.

[u/Godspiral]

Really interesting. Plastic casings and armatures save a lot of weight, but I was always told not to try because steel was required for "proper" magnetic field.

[u/meepstertron]

Hopp Schwiiz! Very nicely presented as well.