Search found 37 matches

by Thecoco974
Jul 31 2020 2:21am
Forum: Motor Technology
Topic: Understanding QS205 efficiency and power
Replies: 10
Views: 324

Re: Understanding QS205 efficiency and power

I'm not sure how it come up with that, if it is setup with the same current the thrust off the 5T should stay higher longer. But efficiency Makes sense, you can see the 5T is more efficient at lower speed. It all come up to your use case. If you need range and city rinding 5T might ne better, if you...
by Thecoco974
Jul 29 2020 3:24pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1176
Views: 105006

Re: APL's DIY axial-flux motor

You're bearing choice isnt' Bad, forces are going to be radial (chain tension) and no axial forces as they should be an equilibrium through the spacers, one bearing should no be all the way one his shoulder for this to happen without loading the bearing. The stator must be stiff enough to resist onl...
by Thecoco974
Jul 27 2020 12:58am
Forum: Motor Technology
Topic: Understanding QS205 efficiency and power
Replies: 10
Views: 324

Re: Understanding QS205 efficiency and power

To make it really simple, Power out = BEMF*phase current. BEMF is linear with speed, so with a higher KV motor, at the same RPM, for the same power out you put more current in your motor. For the same motor a higher KV also means more copper cross section of windings and theoricaly everythings is li...
by Thecoco974
Jul 21 2020 3:02pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1176
Views: 105006

Re: APL's DIY axial-flux motor

Do you have some pics of where it's bending ? and how it looks ? Glassfiber board if dense enough shouldn't be that much less stiff than Aluminum ( glass fibers have a young modulus of approximatly 72 GPa and 6060 aluminum 70 GPa, considering a 60% dense fiber board it should still be 45 GPa) Can yo...
by Thecoco974
Jul 02 2020 4:24pm
Forum: Battery Technology
Topic: 14S3P SPIM08HP passively-cooled pack design
Replies: 0
Views: 114

14S3P SPIM08HP passively-cooled pack design

Hello everyone ! I’m in the process of building a pack out of those SPIM08HP cells. Thought I might share the process here. They have been presented in some other threads I think. I know they are not that good of a cell but at the price we can get them it was the cost-effective option for the power ...
by Thecoco974
Jun 25 2020 12:14am
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1176
Views: 105006

Re: APL's DIY axial-flux motor

Anyway, should have something to show pretty soon. In the meantime, I was looking at the cores today, with the mounting hole I drilled in the middle, and it stuck me,.. did I make a one turn short out of each core by putting a hole in them? Hope not. It's been a long time since you made this decisi...
by Thecoco974
Jun 24 2020 10:20am
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1176
Views: 105006

Re: APL's DIY axial-flux motor

A variable magnetic fields induce a voltage in a conducting path 90° from his vector direction. So a rotating magnetic field induce a voltage in radial lamination. If the isolation is perfect no current is flowing, so all good, but in reality it isn't perfect so small currents are flowing and causin...
by Thecoco974
Jun 24 2020 12:44am
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1176
Views: 105006

Re: APL's DIY axial-flux motor

Having a larger core means more lenght of copper to achieve the same turn counts so more resistive loses, I agree with that, but it also means linking the flux of a larger magnet more efficiently (shorter flux Line) so more flux passing through overall. It all come down to a another compromise we ha...
by Thecoco974
Jun 11 2020 3:59pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1176
Views: 105006

Re: APL's DIY axial-flux motor

Sorry to interrupt so late in the discussion, but to my understanding passing from delta to star configuration is not a x2 increase in phase voltage but x √3 so x 1.73 because when one phase is producing his pic voltage the magnet are 60 electical ° off for the other one hence producing less. Maybe ...
by Thecoco974
Jun 10 2020 5:42am
Forum: Motor Technology
Topic: Regen and voltage rating
Replies: 2
Views: 147

Re: Regen and voltage rating

Thank you for your reply ! That's what I was afraid could happen ... I might need to use some switchable load resistor or use an other controller :cry: Do you have some recommendations for a controller with higher voltage capabilities and good enough control software ? I think nothing is as good as ...
by Thecoco974
Jun 09 2020 8:29am
Forum: Motor Technology
Topic: Regen and voltage rating
Replies: 2
Views: 147

Regen and voltage rating

Hello everyone ! I'm currently working with a three phase generator and looking for a Vesc 75/300 integration for energy conversion. I know a lot off you guys have a really good understanding with those kind of controller, so I come here to seak a little bit off help :roll: . My application is using...
by Thecoco974
Feb 18 2020 3:23pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1176
Views: 105006

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: 1176
Views: 105006

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: 1048

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: 1176
Views: 105006

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: 1176
Views: 105006

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: 1176
Views: 105006

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: 1176
Views: 105006

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: 1176
Views: 105006

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: 1176
Views: 105006

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: 1176
Views: 105006

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: 1176
Views: 105006

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: 2478

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: 2478

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: 2478

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...