First of all, THANK YOU ALL for the recent 1000 subscribers! Here's to another 1000! Secondly, I hope you enjoy this little project! I know I had a fair bit of fun with this one. And if you want to replicate the project or just take a look at the STL files of the 3d printed parts, then the link to the Printables page is in the video description! Unfortunately I had 2 projects in a row fail/go on the backburner for now, and then ontop of that, for the past 2 months I have been troubled with some health problems, hence the long upload break. The next video is likely to take a similarly long amount of time... sorry :/
This is very impressive!! Good for you! You should be proud. I love how you work the numbers into the video in a way that those who want to can stop and look, and those who don't won't be discouraged from watching further or bored. You've gained a subscriber, keep it up!
Lots of epoxy is needed! Super cool project. Would you mind explaining more of the build process and numbers? Id happily watch much longer videos from you. This one was...suggestive. Loved it.
Shouldn't need any epoxy for this one (unless you mean to try to hold on to the electromagnets a bit better :D), just a bit of superglue will do. I didn't test this motor for things like efficiency because I knew it would be very poor and due to eddy currents as well as saturation in the electromagnet cores would mean the motor couldn't function at optimal speeds without destroying itself (as shown at the end of the video) anyways. There are assembly instructions on the Printables page in the description for a step-by-step build process.
Try halbach array on the next one. It deals better with large air gap than the usual style, and functions as a substitute for the iron ring behind the magnets to conduct the magnetic field. 1/8 x 1/8 x 1/4" magnets would be convenient so they can be used radial and tangential facing, or you could use 1/8 x 1/4 x 1/4" for the radial facing ones if they'll fit. Draw a little arrow on the end of each one pointing toward the north pole face to keep track of orientation.
On my axial flux motor, I made the rotors as a halbach array. This particular motor was supposed to be as simple as possible, so not a single advanced topic (no special windings eg. AaABbBCcC, no halbach array, no iron backing, no sensors, etc...) When I get to making my next electric motor (probably sometime in summer), I will attempt to employ some more advanced techniques.
Nice! It would be interesting to make something like this as a generator - as efficient as possible. I believe there’s different things to optimise for that.
Parts looked like you could easily make with better material and home grade cnc. Very well done. I’d like to make hub motor for robot wheels but with gear reduction or somewhat low rpm and high torque. Subbed to fellow tinkerer 🫡
I want to one day make an e-bike motor, which also needs to be a low-rpm-high-torque motor... And yep, a cnc mill and/or a lathe would be awesome to make parts out of better materials... my current living accommodations doesn't allow me to have such equipment though :/... not to mention such tools are quite expensive.
The voltage drop on the PSU is simply because it is not that great of a power supply. It's rated for 33V, 10A or 66V, 5A. But we all know how cheap Chinese import machines behave - once it's getting close to maxing out anything, it's going to start struggling. On my newest video, I use a LiPo battery (which I *did* in-fact buy for the money made from RU-vid videos, thank you very much!) to prevent voltage drop. Such batteries can usually supply many tens of amps before seeing any significant voltage drop.
@@BirdbrainEngineerYes, I understood. My point here is we should match motor to ESC and mechanical load. If we have high kV rate, then it produce less torque and consume higher current. In my opiinion, we should avoid high current if we could. I just want to add one more varible to you to consider. Nice project BTW, love your video. just subscribed.
It's a trade-off of course... Want lower kV? Need more poles or turns, meaning you have to either fit a smaller gauge wire or make the motor physically larger. Physically larger motor is heavier, thus power-to-weight ratio could suffer. Use smaller gauge wire, and your motor can handle less current due to resistive losses. Want the motor to be able to handle more current? Need larger gauge wire, meaning you end with a higher kV or a physically larger motor. With size, once again problem is power-to-weight ratio, and with higher kV the problem is, as you already stated, proportionally lower kT. The e-bike motor I will be making I will actually do proper calculations beforehand to figure out how many turns I need and how much heat generation I expect at any given load and so on. Thanks for the subscription!
I have not yet made it, I am planning it out slowly, and probably will end up building it early next year; Winter is coming in the Northern hemisphere, so the seasonality isn't great for publishing an "e-bike" video for the next few months. Until then, I will have some non-electric motor videos planned, including the third air pressure engine design.
Thanks! Next few videos will be about less mechanical things; Haven't touched on programming-related stuff for a while now, so next one is probably on that ;)
It would burn up within seconds... For now my motor making effort will go into making the axial flux e-bike motor, probably some time early-ish next year. But I definitely am thinking of maybe trying to actually make a structurally (obviously control electronics and a battery would not be possible to 3d print haha) fully 3d printed drone after the e-bike project...
man you are amazing, thank you very much! fore sure i would enjoy more videos like this and especially a follow up on the axial motor with stole's too!! :))
I have been curious about making my own ultralight brushless motor for sometime now...maybe I will start with something small like this first. Cool channel!
Good luck! For an actually useful motor you'll need to do a bit more work than what is shown here but this video will give you a solid foundation to understanding how to make one and improve upon.
I was inspired to make my own. My magnetic cores are made of 10.9 alloy steel bolts with a thin 3d printed jacket to prevent damaging the isolation. It seems that the magnetic permeability was good, and retentivity was good enough when testing with a magnet, but I similarly am running into hysteresis heating issues. Luckily the "cores" are screwed directly into a large washer I found in the street so the heating won't immediately destroy the motor.
Yep, construction mild steel is really not that good of a material for magnetic cores, especially when it is a bulk material like that. For the future I have a different design in mind that should have much less hysteresis and eddy losses.
Magnetless (guessing you mean permanent magnet-less) motors are quite common - starter motors in cars are a perfect example! The main advantage for such motors is that they are cheaper and can't break due to demagnetization (which would often happen at a much lower temperature than what the copper wire insulation can handle). There is another application for magnetless motors... well... generators. A large majority of large electric grid generators (think in dedicated power plants) use electromagnets instead of electromagnets. And once again the reason is that it is cheaper and actually also allows for a little bit more control over the amount of power the generator produces.
The assembly manual is unbelievably well done ! This is really high quality stuff, provided for free ! You must have spent so much time making it. BTW how did you get those gorgeous renders ? The texture on the 3D printed parts is immaculate.
I use Blender for rendering :) And yeah, I try to get better with documentation every time - writing the first batch of documentation for my next project as we speak haha.
A dual-rotor set-up for a radial flux motor is highly unusual and absolutely not a "simple" thing to do. I actually can't recall ever having seen a commercial dual-rotor radial flux motor before. For axial flux it makes more sense.
This is awesome! You were able to get 11.4v at 5 amps, which is basically a DIY 50 watt BLDC motor?! I wonder if some of your screws that fit the pieces together can be replaced by plastic clamps, perhaps using a compliant mechanism that holds things together tighter with stronger rotation. Resulting in a lightweight superefficient motor where the only metal is bearing, coils and magnets.
The 5A can only be held for some time... eventually the coils would heat up too much and the PLA would melt. Should use something like polycarbonate next time, which would melt only at ~140C
The point of this motor was to be extremely easy to make, so using parts that are in basically any hardware store. Pure iron nails or screws or rods, whatever have you, are actually not that common, let alone proper electrical steel (unless you rip the stator out of an old motor, but that kind of defeats the purpose anyways lol... at that point you are basically just rewinding and adding a new rotor)
Awesome! I'm really interested in 3D printing, smaller projects like this look really fun. I have an idea for something that needs gear torque multiplication to help with leverage, if you'd like to see it let me know👍.
You can make a motor with 2 phases, or indeed, even just a single phase! However, such motors will have worse power output characteristics (eg. the torque will be quite varying throughout the electrical rotation). If one makes a 2 phase motor or a 1 phase motor then the distribution of electromagnet poles and magnets is different as well, so it's not as simple as just simply using this design with simply 2 phases.
Haha... yeah I am just trying out variations on the style of commentary and editing and so on with nearly each video... One day I will find some style that I like...
