Search found 474 matches

by mxlemming
Sep 23 2021 3:04pm
Forum: Motor Technology
Topic: FLIPSKY new 20s 100A tiny controller (vesc based)
Replies: 39
Views: 811

Re: FLIPSKY new 20s 100A tiny controller (vesc based)

IMG_20200901_214317.jpg Lol at that ti note. That's a ti csd19535 with a200A package limit. The thin section of the leg and PCB just vaporized with a 40A fuse in the battery line. Photos pre burning show it was soldered well. Not masses of solder but well enough. Yes there was a firmware issue that...
by mxlemming
Sep 23 2021 10:37am
Forum: Motor Technology
Topic: FLIPSKY new 20s 100A tiny controller (vesc based)
Replies: 39
Views: 811

Re: FLIPSKY new 20s 100A tiny controller (vesc based)

john61ct wrote:
Sep 23 2021 9:11am
So rated for drawing 100A continuous from BATTERY

does that mean 180-200A is possible to the motor when low RPM is dictating say 36V internally?
No.
by mxlemming
Sep 23 2021 6:47am
Forum: Motor Technology
Topic: FLIPSKY new 20s 100A tiny controller (vesc based)
Replies: 39
Views: 811

Re: FLIPSKY new 20s 100A tiny controller (vesc based)

So guys do you think it will allow to set max motor AMP to Somewhere around 160A? Just a suggestion: Ask them :). They've responded to my emails pretty fast. Probably better than speculation, at least than MY speculation anyway :) So ill stop speculating before I say something dumb again. :) Br, I'...
by mxlemming
Sep 23 2021 3:24am
Forum: Motor Technology
Topic: FLIPSKY new 20s 100A tiny controller (vesc based)
Replies: 39
Views: 811

Re: FLIPSKY new 20s 100A tiny controller (vesc based)

OK I was making assumptions about that 84V, 75V÷20S is 3.75V figured close enough to li-ion nominal. Well, good news! Flipsky replied to my inquiry and it seems it really is 20s capable. So you were quite a bit closer to the truth than me! As this esc is based on vesc (Benjamin Vedder esc opening s...
by mxlemming
Sep 23 2021 2:02am
Forum: Motor Technology
Topic: New ground-up ESC - MESC_FOC_ESC
Replies: 173
Views: 9882

Re: New ground-up ESC - MESC_FOC_ESC

Hi mxlemming, Thank you for the detailed response. As for the MOSFETs; I'll try to pick one from your recommended list and report my findings here. Generating the Gerber files will hopefully give me a chance to brush-up my KiCAD as well. If I understand the KiCAD workflow correctly, one starts with...
by mxlemming
Sep 22 2021 5:30pm
Forum: Motor Technology
Topic: New ground-up ESC - MESC_FOC_ESC
Replies: 173
Views: 9882

Re: New ground-up ESC - MESC_FOC_ESC

Hi all, First of all thanks for the incredible work by mxlemming and everyone who contributed to this project. I'm not sure if this thread is still active but I wanted to ask a few questions: 1. The github repo consists of a number of folders (R2 Outputs, R2.1 Outputs, R2.2 Outputs V0.5 Outputs) wh...
by mxlemming
Sep 22 2021 1:52pm
Forum: Motor Technology
Topic: True FOC: definition and examples
Replies: 115
Views: 8476

Re: True FOC: definition and examples

john61ct wrote:
Sep 22 2021 1:26pm
Tiny and cheap VESC 72V 100A (phase amps or battery? )

viewtopic.php?p=1677954#p1677954

Question, being VESC, automatically means yes "true FOC"?
VESC = true FOC. Yes.
by mxlemming
Sep 21 2021 3:01pm
Forum: Motor Technology
Topic: DIY Toroidal Axial Flux PM
Replies: 226
Views: 8394

Re: DIY Toroidal Axial Flux PM

Also, in googling the subject of using FOC to drive low inductance motors. I came across a video of a gentleman Benjamin Vedder that shows he is able to drive a very low inductance, and large motor using FOC in a VESC 75 controller. I saw it on the internet, so it must be possible :) fbK2dcoYS7g It...
by mxlemming
Sep 21 2021 6:08am
Forum: Motor Technology
Topic: FLIPSKY new 20s 100A tiny controller (vesc based)
Replies: 39
Views: 811

Re: FLIPSKY new 20s 100A tiny controller (vesc based)

This looks really good and flipsky aren't jokers... The thing that stands out to me as problematic is it's listed 75100 which implies it's based on the 75300 which uses components not capable of 20s. That needs clarifying. When you get it, please rip apart and get photos of the innards., that will q...
by mxlemming
Sep 21 2021 3:57am
Forum: Motor Technology
Topic: DIY Toroidal Axial Flux PM
Replies: 226
Views: 8394

Re: DIY Toroidal Axial Flux PM

Low inductance for our kind of motors is usually a problem rather than a help. If you consider 30kHz switching, 50%duty, that's about 15us with half the bus voltage going into winding up the inductance (the other half pushes against back EMF) So consider say a 50uH motor (like on my bike)... 50Vrai...
by mxlemming
Sep 19 2021 12:37pm
Forum: Motor Technology
Topic: Building a motor
Replies: 52
Views: 1497

Re: Building a motor

I can imagine possibly worse transferring of heat to the stator from the wire with LRK although never heard of that as a reason not to use it (with good airflow transfer heat right off the wire and forget transferring to the stator.). The reason I hear for why not used is due to it having slightly ...
by mxlemming
Sep 19 2021 11:19am
Forum: Motor Technology
Topic: DIY Toroidal Axial Flux PM
Replies: 226
Views: 8394

Re: DIY Toroidal Axial Flux PM

Low inductance for our kind of motors is usually a problem rather than a help. If you consider 30kHz switching, 50%duty, that's about 15us with half the bus voltage going into winding up the inductance (the other half pushes against back EMF) So consider say a 50uH motor (like on my bike)... 50Vrail...
by mxlemming
Sep 19 2021 10:31am
Forum: Motor Technology
Topic: Building a motor
Replies: 52
Views: 1497

Re: Building a motor

I have never really considered this single layer winding option, no one ever seems to do it, so I assume it must be bad, but I can;t really see why. If anything, and particularly with this N and P option, it looks intuitively like a really good wind, and less fiddly (though the same amount of turns ...
by mxlemming
Sep 19 2021 3:49am
Forum: Motor Technology
Topic: DIY Toroidal Axial Flux PM
Replies: 226
Views: 8394

Re: DIY Toroidal Axial Flux PM

I don't quite understand but that looks quite serious. Another question... Did you measure the inductance of your motor? I'm worried it might be crazy low. If you've not got an ESC that can measure you can put a capacitor (PP or ceramic, few uF from memory) across two of the legs and give it a littl...
by mxlemming
Sep 18 2021 2:55pm
Forum: Motor Technology
Topic: Building a motor
Replies: 52
Views: 1497

Re: Building a motor

I bought the only stator I could, this: 36n stator.PNG I am going to try to assemble the motor like this, with a halback array to avoid back iron, which will be PITA to get. Unfortunatlely, this ends up with about 600g of magnets, but it's still far easier than getting back iron in the exact radius....
by mxlemming
Sep 18 2021 7:17am
Forum: Motor Technology
Topic: A Small 6 fet Vesc 6 Design
Replies: 19
Views: 704

Re: A Small 6 fet Vesc 6 Design

It's only meant for 30 amps and I will thicken up the exposed solid regions with extra copper. I managed to get those capacitors on the top side of the board and also became aware of a missed connection which I fixed. Huge thanks for that. The ncp5183 requires too many external components which I c...
by mxlemming
Sep 17 2021 9:16pm
Forum: EBike Build Threads
Topic: The Wood Chopper
Replies: 17
Views: 893

Re: The Wood Chopper

This is why i love this forum, the weird and wonderful creations people make.

I don't understand why anyone would ever think making a bike from plywood is a good idea, but you've done it and the execution looks fantastic.

How fast is it?
by mxlemming
Sep 17 2021 9:03pm
Forum: EBike Build Threads
Topic: Giant Trance Belt drive with MESC @ few kW
Replies: 22
Views: 830

Re: Giant Trance Belt drive with MESC @ few kW

In other news, I programmed the MESC to have a power limiter so despite this upcoming power, I will be able to run it in some kind of eco legal mode at 250W and get something like 100km range if all goes well...
by mxlemming
Sep 17 2021 8:56pm
Forum: EBike Build Threads
Topic: Giant Trance Belt drive with MESC @ few kW
Replies: 22
Views: 830

Re: Giant Trance Belt drive with MESC @ few kW

So having given up on the neumotor, I found this (well hummina pinned me to it): Ant innovation at12070 with 120mmOD and 102mm stator. It's more than I'd ever intended to part with for this project but it should turn this into a complete monster. Screenshot_20210918-022716.png This is a pic of them ...
by mxlemming
Sep 17 2021 7:15pm
Forum: Motor Technology
Topic: A Small 6 fet Vesc 6 Design
Replies: 19
Views: 704

Re: A Small 6 fet Vesc 6 Design

This will probably work, but I don't think it'll be great for high power. There are a few thin areas though i guess you plan on adding copper to them. I'm not sure why you've got 3 random bootstrap caps on the back of the board. They can easily go on top. Check your battery+line. It looks to me like...
by mxlemming
Sep 17 2021 2:54pm
Forum: Motor Technology
Topic: Building a motor
Replies: 52
Views: 1497

Re: Building a motor

Using the freewheeling crankset with this double freewheel drilled so can use the 17tooth. Have a frame being custom made w this motor mount in the seat tube. I havent wound the motor yet so maybe will wind for lower kv and will see the no-load draw at around 9000 rpm. And then with voltage sag and...
by mxlemming
Sep 17 2021 2:32pm
Forum: Motor Technology
Topic: DIY Toroidal Axial Flux PM
Replies: 226
Views: 8394

Re: DIY Toroidal Axial Flux PM

Am also quite confused by jrbes model.

Could you put some magnets and copper in it to explain?
by mxlemming
Sep 17 2021 2:25pm
Forum: Motor Technology
Topic: Kelly Controller power ratings
Replies: 7
Views: 169

Re: Kelly Controller power ratings

From a rating perspective phase current is the important one, battery current is kind of irrelevant. Phase current is what the motor and MOSFETs see. For bldc at max speed phase = battery current, for sinusoidal there's some sqrt3s in there. At zero speed, battery current can be tiny and phase huge....
by mxlemming
Sep 17 2021 2:02pm
Forum: Motor Technology
Topic: Building a motor
Replies: 52
Views: 1497

Re: Building a motor

https://www.anttilehikoinen.fi/technology/electrical-engineering/pole-count-good-bad-ugly/ https://www.rcgroups.com/forums/showthread.php?2934319-motor-with-more-poles-give-more-torque-again I’m also wondering what’s an ideal rpm range for efficiency but figure it’s a toss up depending how heavy ha...
by mxlemming
Sep 17 2021 11:08am
Forum: Motor Technology
Topic: Building a motor
Replies: 52
Views: 1497

Re: Building a motor

will core losses increase with higher current even before saturation? makes sense but never see it mentioned and seems skipped in rc plane calculators or simulators I think not necessarily, since the permanent magnets provide the most significant field at lower current, and the current induced fiel...