Re-wind of a turnigy 80/100 (Now-tutorial w/Video)

[Danny Mayes]

Nope, that didnt work...

How do i embed an image??

All my bench testing shows these motors really don't like to spin above 9500 rpms. There is a huge spike in the heat generated at that point I can only assume is Iron loss/core loss. doesn't seem to matter the wind...

Thats good info to know. harmony really goes out the window when you get too fast with those motors. I think it's real wise to gear for top speed just shy of 9500. I am going to plan for that. Gold info indeed

Wrt the 3 speed, my secret plan was to do some 3D fiddling with it. If and when it's OK with you of course :wink: . I would love to see how it works. I can get the 2 speed easy enough but have no idea how to implement a 3rd gear...

D

 

[Ludo91]

hey folks! some calculation about temeprature of these motors!

I`m rewinding it again in 5T (I failed at doing it 6t, was my first rewinding and I did a bad job. It happens, just do it again!), various calculatios shows that it will have 15mohm resistance in delta and 26 in star.

that means in 250 watt dissipated @ 120A and 486 @ 180 in delta and 432, 840(!!!) in Star.

Therefore, I`ll limit its current to 180A when in delta and 120 when in star.

so, to be pessimistic, 490Watt to dissipate in heat.

copper termic capacity 385j*k/kg

I got 150 g copper, that means that at 490 watt dissupation the Tcopper rises of 8c/ seconds.

i may need those peak powers (180A @ 36 v is 6.4KW, pure hell on a bmx!) for about 10 secs once in a while, will the motor survive??? what it its thermican dissipation capability to the armature?? I`m thinking more and more setiously of watercoolin it

 

[hydrus]

Hello!
I'm a first time poster here but have been reading this forum for quite a while now (and specially the non-hub and motor technology sub-fora)

I was wondering if anyone had tried rewinding a turnigy with copper foil instead of wire. Something like 0.1mm thick and as close to 16mm wide as possible.
I have this technique in my mind where I would solder a normal magnet wire to the foil at the wire-outlet end of the stator and wind the foil round the stator and that wire (the magnet wire which would come out of the windings radially)

The turns would be isolated with a strip of kapton or mylar in between.
Copper foil is used in high end audio transformers and some radio equipment and I don't see why it couldn't work in a BLDC.

This way it would be possible to make really low Kv motors (I believe 20 turns would be possible in a 80-100)
Is their anybody who thinks I made a huge mistake and it's definitely not possible or should I give it a go and see what happens?

 

[Lebowski]

Hello!
I'm a first time poster here but have been reading this forum for quite a while now (and specially the non-hub and motor technology sub-fora)

I was wondering if anyone had tried rewinding a turnigy with copper foil instead of wire. Something like 0.1mm thick and as close to 16mm wide as possible.
I have this technique in my mind where I would solder a normal magnet wire to the foil at the wire-outlet end of the stator and wind the foil round the stator and that wire (the magnet wire which would come out of the windings radially)

The turns would be isolated with a strip of kapton or mylar in between.
Copper foil is used in high end audio transformers and some radio equipment and I don't see why it couldn't work in a BLDC.

This way it would be possible to make really low Kv motors (I believe 20 turns would be possible in a 80-100)
Is their anybody who thinks I made a huge mistake and it's definitely not possible or should I give it a go and see what happens?

What would be the intended goal of using copper foil ? What would be 'extra' as opposed to using 20 windings of thin wire ?

 

[bearing]

This is such an excellent thread!Thank you for sharing.

On page three Biff posted an analysis of the motor, and also some FEMM simulation scripts. Those attachments are now broken. I messaged him about it, and he suggested that I ask here for the files.

Did any of you save those files, and could you please re-upload them?

I would appreciate it, thanks.

Here is the FEMM simulation, and the 3 different lua scripts I use to evaluate it, and the spreadsheet all in a .zip file.

-ryan

 

[Miles]

I was wondering if anyone had tried rewinding a turnigy with copper foil instead of wire. Something like 0.1mm thick and as close to 16mm wide as possible.
I have this technique in my mind where I would solder a normal magnet wire to the foil at the wire-outlet end of the stator and wind the foil round the stator and that wire (the magnet wire which would come out of the windings radially)

We've discussed something similar before, in a different context. You can also have 2 contiguous, side by side, flat section coils, starting the wind in the transition between them (see pic). The thickness of the copper section needs to be significantly greater than that of the the insulation layer....

Leaving aside the practical difficulties, I'm doubtful a single flat coil would give a better fill for the Turnigy slots? The technique is more suited to axial flux stators.

 

[Bazaki]

Not many people read the Watercraft forum I believe so I post a link in here.

http://endless-sphere.com/forums/viewtopic.php?f=39&t=33547

I am looking for a way to get about 2400 RPM speed out of the Turnigy 80/100, I did not read all these pages in this topic, but rewinding to about 51 rpm/v is possible ?

Another solution is maybe a gearbox to reduce the high rpm, but how or where to get a gearbox?

Or maybe another big brushless motor with a diameter of 100mm ?

 

[Thud]

A 12 turn single 14g terminated in wye yeilds a kv of 55. close enough?
[youtube]DpM2McmM1ms[/youtube]

 

[Bazaki]

Perfect ! Do you think the motor can run at 100a for about 3minutes ? And could a big Ebike controller take care of this ? Thanks.

 

[Miles]

Do you think the motor can run at 100a for about 3minutes ?

3 mins is a long time for such a small motor. It's unrealistic to expect it to be able to sustain 17Nm.

 

[bearing]

Hi again, I'm bumping this. About 50 people downloaded "For-Thud.zip", but it's broken now. Could you re-upload it, please?

On page three Biff posted an analysis of the motor, and also some FEMM simulation scripts.

 

[Thud]

Perfect ! Do you think the motor can run at 100A for about 3-minutes ? And could a big Ebike controller take care of this ? Thanks.

100 amps at what voltage?

Ive been running these motors with the 12-FET controllers & I have been winding with 18 cells in mind without issue. (other than the time it takes to re-wind & fit the hall sensors) The important thing to remember is these motors are optomistically mis-represented in the hobby world...I am finding the practical limits of any of the 80-100 motors to be in the 4 or 5 Kw range for continuous operation...for a 3 minute insane speed run you can ramp up the loadings & see where the set-up leads you before the thermal critical point gets you.

I doubt even my modded 12-FET controllers will take 100 amps for 3 minutes....going to need bigger for that.

*bearing, I think those files were lost in a server change-over...I don't have a copy on this computer. maybe Biff has it saved some where accessable.

 

[Bazaki]

Thanks, well I want to run it at 44v 12s lipo. And need about 2500rpm. 6000watt so i need 2 motors at one shaft and 2 controllers

 

[bearing]

bearing, I think those files were lost in a server change-over...I don't have a copy on this computer. maybe Biff has it saved some where accessable.

I asked Biff, and he was very busy. He said he could maybe search for it in some weeks, and suggested that I instead asked in this thread. I replied that he didn't need to bother searching for it, because I thought he had done enough producing it in the first place, and I was sure that someone in this thread would have it... =)

 

[Thud]

I thought i had it saved on a USB.....Can't seem to find it now. (most of the info was over my head anyway & a little out of context...) but its gone for now. Sorry.

 

[etard]

Hey T,
I'm having a hard time trying to find out the torque output of your custom wound motors, do you know the newton meter output at say 5kw? Is it 17kw as Miles stated earlier? The reason I ask I that I am debating on tryin to slim down the drive further by mounting one of these inside a jackshaft pulley after a 2:1 reduction so I'll need twice the output rating as the motor:

http://www.vxb.com/page/bearings/PROD/One-Way-Bearings/Kit10970

 

[Thud]

Here's a SWAG at it.
looks like nearly 15 Oz/in per amp as Kt...soooooo, at 100 amps your makin' 1500 oz inches or effectivly 8Nm of torque at the motor shaft.

multiply that by whatever your reduction is & you'll need a bearing rated at 10x that for reliability.

(scientific wild ass guess)

 

[kfong]

Bearing, I went through my notes is this what your looking for?

 

[Bazaki]

After rewind, would it be possible to add watercooling ? And has someone done this before or any idea how this can be made ?

 

[Thud]

B,
there is a long discussion about cooling these motors starting on page 7 (it continues for 7 pages) lots of ideas & a test....but we definitely need more testing & ideas, if limits are to be explored further.

 

[Ludo91]

guys... As I told ya in my topic "help in building my own bldc controller" I put the "hot stuff" about my ebike on the shelf in order to be able to work hard for college... but still I cannot resist to do some little works on the bike, one of these days Im gonna try to put a ductjed fan on the top of the motor to see is forced air cooling does something cool... i`ll keep u up to date... it may be a while tho :wink:

 

[bearing]

Bearing, I went through my notes is this what your looking for?

Yes! those are the files.
Many thanks man=)

 

[etard]

I am in the middle of training hamsters to fan the motor with feathers, but now that you mention it, a ducted fan sounds almost as easy. :lol:

But why even have an external motor when a fan can just be mounted on the shaft? Hey Thud, weren't you working on something similar? Of course you know my thoughts on the subject which imay have to incorporate on the Racer X build.

By the way guys, I just got two of Thud's latest winds and the pro winder is starting to become a Jedi, so save yourself some headaches and have him message you motor.

 

[RWP]

...By the way guys, I just got two of Thud's latest winds and the pro winder is starting to become a Jedi, so save yourself some headaches and have him message you motor.

OK then, tell us - show us what you got What winds and such - and pics to match

 

[etard]

Ok then Roy, you asked for it!!

Then one just to make you jealous, there's over 15 kw of potential there:

I'm thinking of sending this 80-85 in for a wind, I actually want to bump up the KV a bit closer to 200 with better bearings to take the abuse along with hall sensors for the ultimate option.


One thing I must say, be sure to get the Thud 4 1/2" shaft cut off signature! I do believe the guy carries extra cutoff disks in his wallet where condoms used to reside. :lol: :lol: