I have decided to make a quadrocopter from scratch. The rule is: spend as little money as possible and buy nothing unless you absolutely need to.
However, I am not experienced in making electrical motors. I have found this site http://www.flyelectric.ukgateway.net/motors.htm that I' ve found helpful, but I would appreciate if you could point me to another webpage or maybe a how-to. I also wouldn't mind reading a bit(or a lot :)) of theory on electrical motors, as I have a very rudimentary understanding of them at best.
Also, have you ever made your own motors? What problems did you face etc.?
brushless motors are different from most motors, and simpler mechanically. Alas to make one from scratch
requires access to lathe(s), and you'll have to get laminations stamped out, which is rather tricky without
access to relevant tooling. Perhaps look for getting a kit that can be rewound, or rewind an existing model,
but honestly RC brushless motors are mass produced and good value in the smaller sizes.
I was thinking of buying the parts you would make with a lathe(stator and rotor if I'm not mistaken).
I am aware that I can get a good brushless DC for as little as 10$, but I want to make one
myself in order to get an understanding of how they work.
The rule is: spend as little money as possible and buy nothing unless you absolutely need to.
I suspect you can buy a motor cheaper than you can build one. They manufacture the parts in bulk and assemble the motor on an assembly line with a couple minutes of cheap labor per motor. The marketing & distribution costs are probably more than the parts & labor. So they can sell it to you cheaper than you can make it, and still make a nice profit. That's capitalism, baby!
I think I might have made a motor as a science project when I was a kid. But, it didn't look anything like the ones on the flyelectric website, and it didn't have the efficiency of a "real motor" so it wouldn't have had the power-to-weight ratio to get off the ground. ...I remember winding wires around nails to make an electomagnetic, but I don't remember if that was part of a motor.
I think he is making this project as hard as possible on purpose. If that is the case, kudos, wish I had the time for that. I would say try re-winding/rewiring a motor that is like what you need and try and make it better. even if its not better than when you started, you can still say you made it. Maybe you will even find room for substantial improvment.
I am gonna beg to differ on that point, carburettors are a mix of fluids, mechanical engineering, magick, form, packing, and some flow parameters that somehow were conqured 50 years ago even tho we can't quite model it still today.
I made a motor when I was a kid. It came as a kit; All the parts were premade and I pretty much just wound the wire and snapped it together. It required one D cell and rotated with a squeaky noise. It was a good lesson on magnets, electricity, armature, and brushes. It was not a good lesson on horsepower or efficiency though... I could stall it very easily and the battery soon died.
If you want to learn how a motor works, find one in toys, electric mixer or drill, or fans. Take it apart. Learn what makes it go around. Appreciate how they are made, and realize that they are not simple devices. For a quadrocopter you would want small, efficient, and powerful motors... due to practical purposes, a homemade motor can only be one of those.
Grumpy_Mike:
Ever wondered why people don't make there own carburetor?
Or analog wristwatches!
If your planning on building a quad-copter you are already taking on a huge challenge and as the Asian DC brushless motors are very inexpensive for the power they deliver, I would think carefully about where you choose to spend your time, effort, and money to get the most bang for your buck. But do what makes you happy as that is the function of a hobby.
That name brings back memories. The refinery I worked at went through a 'quality improvement phase' in the mid 80s. Several of us were 'anointed' to become part time quality improvement coordinators, QICs. I even got to attend a training seminar taught by Dr. Deming in San Diego. Won't say the teaching took good and lasting hold at the refinery but there was some change in management style after some had exposure. Simple concepts, lots of logical thinking, but a whole lot harder to implement correctly then one can imagine.
Yep, I attended one of his seminars and it really made the light come on. Quite a challenge to get an entire organization to see it though. He would attend a regular meeting at GM once or twice a year, I would try to get to those when he was there. That might have been where the carburetor quote came from. Pretty tall guy, he could be quite imposing, and he just roared it. He then went on to explain that the reason for the disappearance of the makers of carburetors was because they were in the wrong business; namely, the business of making carburetors, when they should have been in the business of "delivering a stoichiometric fuel/air mixture to the cylinders".
carbs are just slow fuel leeks. electric motors are much more complex, though still not that hard to build.
take apart an old hobby motor and see for yourself. or hit up youtube.
That might have been where the carburetor quote came from.
Well if it did it was a coincidence, I just wanted to find an analogy for something that looked simple and basically is, once you have set up all the infra structure around the project.
I too have made my own electric motor, but there is no way it would deliver enough power to fly. The electrics of it as simple but the mechanics require precision much more accurately than ... so I came up with carburetor.
