Search found 26 matches

by Thecoco974
Feb 18 2020 3:23pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

It look like an hybrid between a reluctance motor and an axial permanent magnet. The toroïdal stators are similar to some coreless motor we've spoken off before (but this Time they have an SMC core to loop back the field) and are interacting with the magnets I guess. And everithing else juste work l...
by Thecoco974
Jan 11 2020 5:46pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

The best way is to model your motor on FEMM and play with the back iron thickness, it's not a difficult programm too learn. Once you're model is set you just need to add thickness until all the flux line are in the back iron. I'have done that for my design and came out with a thickness of 4.8mm back...
by Thecoco974
Dec 02 2019 9:28pm
Forum: Motor Technology
Topic: Motor with Electromagnets on Stator and Rotor?
Replies: 2
Views: 1001

Re: Motor with Electromagnets on Stator and Rotor?

It's called an "wound rotor synchronous motor" and the stator is usualy powered with brushes.
If the stator is closed loop on itself it's called an asynchronous motor or induction motor and the stator doesn't need external powering

Envoyé de mon Redmi Note 3 en utilisant Tapatalk

by Thecoco974
Nov 22 2019 1:41pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

Looking good ! :) I don't know thé CAD software you're using. But all the one I have used si far used two different type off file for Part and assembly. Is this one similar ? If it's the case part are assembled using constrains and most of the time you can design a part directly on top of another on...
by Thecoco974
Nov 03 2019 8:48am
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

A properly cooled motor is an efficient motor as APL said. Why are you spliting the two ? A motor efficiency or figure off merit can be described by the torque constant divided by the root of the impedance. A cooler motor mean a lower resistance and more power for less coper, less weigth and by so a...
by Thecoco974
Nov 01 2019 8:31am
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

Thinking about it a little, aluminium seems to be not a so bad option for Big axial flux with high winding Space when conductor fill isn't a huge concern. But for coreless i'm not sure it's a good bet since we want the maximum conductor density in the smallest intermagnet space. For cost it means wi...
by Thecoco974
Oct 31 2019 9:38am
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

Ok now i see why you're looking into external fan cooling :) Trial is a very specific use case but actually a very good match for an electric swap (loads of low torque needed). You're talking about aluminium conductor on a coreless build ? That's really interesting ! Have you found a way to limit Ed...
by Thecoco974
Oct 31 2019 8:28am
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

i've thought about the lack of airflow at low speed as well, m'y conclusion on it is that a motor is quite heavy ans as a lot off thermal inertia, si when you design the cooling you need to look at the average speed it's going to turn, of course if you do stop and go at low speed it's not favorable ...
by Thecoco974
Oct 31 2019 5:58am
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

Sorry I haven't write it right ! When I said the sides it was seeing by the axle, like you said air doesn't want to be forced from thé outside to the inside (radially) it's counter intuitive. Lebowski actually notice a good airflow with his diy 3 rotor, the interaction between the air and the rotor ...
by Thecoco974
Oct 31 2019 12:27am
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

Of course the air need to come out of the motor by the sides. The way you can look at it is that when you make the motor spin, air want to spin with it, when it does, there is nothing counteracting the centrifugal force so it's flying outwards. The angle of the blades is a hard thing to calculate, i...
by Thecoco974
Oct 30 2019 2:54pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

I plan on doing something like this with my coreless build : v3.PNG The part with the blades is machined as one piece with the bake iron on a disc of steel. It makes sense for me since it's a rather thin motor but for you not so much ! Another thing to look at is that mine is made to turn all the wa...
by Thecoco974
Oct 10 2019 8:30am
Forum: Motor Technology
Topic: DIY Motor Dyno/load?
Replies: 24
Views: 2085

Re: DIY Motor Dyno/load?

I know the 4 quadrant of motor operation, It appears I havent' understand it as well as you did ^^ For me when torque and rotation are in opposite direction it mean that the motor is producing negative work or generating power. But you tell me that the controler can actively drive the phases 90 degr...
by Thecoco974
Oct 09 2019 9:59pm
Forum: Motor Technology
Topic: DIY Motor Dyno/load?
Replies: 24
Views: 2085

Re: DIY Motor Dyno/load?

shaman I just dont understand when you and Peter are saying : "the second one also in drive mode with lower torque, that would rotate backwards" For me BLDC being synchrnous motor (and it apply to other motor technology) you cannot just run it in opposite direction of the driving motor, either they ...
by Thecoco974
Oct 09 2019 8:12am
Forum: Motor Technology
Topic: DIY Motor Dyno/load?
Replies: 24
Views: 2085

Re: DIY Motor Dyno/load?

to be clear I'm not intending to use the alternator as an alternator. I would convert it to a motor that would then oppose the motor under test. That's what I call a generator or alternator :P. Same hardware, positive energy. Of course the best is to dump back the energy in the battery. If you're p...
by Thecoco974
Oct 08 2019 5:58pm
Forum: Motor Technology
Topic: DIY Motor Dyno/load?
Replies: 24
Views: 2085

Re: DIY Motor Dyno/load?

Yes, it's a good way of doing it. But might become expensive very quickly since the generator-controler combo must be a least capable of handling the max power of the motor tested. If there is no need to control the load precisely, like you said an oversized industrial motor with a massive load is o...
by Thecoco974
Oct 08 2019 8:46am
Forum: Motor Technology
Topic: DIY Motor Dyno/load?
Replies: 24
Views: 2085

Re: DIY Motor Dyno/load?

If you just want to load your motor and don't need any power data, the quickest methode I can think of is simply braking it, either by using the brakes on the vehicule it's mounted on or putting some disks brakes on an axle. (May not work for long before overheating though) Envoyé de mon Redmi Note ...
by Thecoco974
Oct 06 2019 10:38pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

Thecoco974, those U clamps could be made of composite, and there wouldn't be any 1T short, I think. I'm still not sure which is better, steel, or an aluminum ring,.. but we can try both, they're bolt on's. Yes they can be made with composite, but aluminium would give better heatsinking capabilities...
by Thecoco974
Oct 06 2019 11:47am
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

APL, I see the one turn short too and it need to be taken out of course. Like you said one way is by making the plate electricaly and magneticaly in the same circuit by using magnetic materiel and having an electrical contact between the disk and the core, but that way it make the magnetic circuit o...
by Thecoco974
Oct 04 2019 10:03pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

Actually you were right Fechter, if the screw head is sufficiently buried flux wont go much trough it : screw_flux.PNG Here the simulation is with N52 magnet (20x5mm), 5mm screw heads ans 4mm body, 20mm wide core face, and 10mm wide core. I might have made it too narrow, but it shows that depending ...
by Thecoco974
Oct 04 2019 9:18pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

Flux need to go from one magnet through the first core, trough the ring then the other core and the opposing polarity magnet. If the cores are touching each other on the side away from the rotor, all the flux will pass to the adjacent cores instead of through the support ring. The support ring will...
by Thecoco974
Oct 04 2019 3:41pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

The support ring for the cores should go all the way to the outer edge for the most support. If the support ring was fairly thick aluminum, it could be used to carry heat away from the cores if it was attached to the housing. Water cooling could even be done by having channels or tubes on the suppo...
by Thecoco974
Sep 23 2019 12:19am
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

One thing to keep in mind is the spacing between the two rotors needs to be fairly small compared to the width of the magnets or else the flux will fringe (short out) to the adjacent magnet instead of going to the magnet on the other rotor. MFEA models are pretty good to see how this works but I do...
by Thecoco974
Sep 20 2019 4:53pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

Sorry, my explanations are not the best ! When looking at max torque production, the magnetic field of the magnet and the magnetic field of the coil should be 90° as shown here with a very large airgap : https://uploads.tapatalk-cdn.com/20190920/54fa44ae4c230dd16221cb5ef6e178bc.jpg We can see that w...
by Thecoco974
Sep 19 2019 11:04pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

How I understand it is that there is two ways of looking at how the torque is produce, one way is using the Laplace forces (Lorentz same thing) as Lebowski said. The torque is at his max when a magnetic field is crosing the more activ turns in wich current is flowing in the same direction, so when t...
by Thecoco974
Sep 17 2019 4:44pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1015
Views: 86162

Re: APL's DIY axial-flux motor

I think that as you said using a single rotor on the inside make sence for lowering the magnet mass without massive torque losses, but it also mean the use or a back-iron on either side or as you said rotating Steel disk to close the magnetic circuit. If the rotating disc have some slot milled-out m...