Need Advice Rewinding BL Motor To Get Higher KV

[phupper]

I have a dead 3530-10 25A BL motor I bought from HeadsUp RC. It was sold as an 1100KV motor, and spins a 10x5E prop at about 24A. It has 12 poles and 14 magnets, but I don't know how many turns per tooth. I believe it's a DLRK wind.

I'd like to rewind this motor for a higher KV so it can turn a 6 inch prop at about the same 24A.

How many turns per tooth, and what termination would accomplish this?

Thanks!

Phil

[ron_van_sommeren]

See my answers in this thread:
http://www.rcmf.co.uk/4um/index.php/topic,67286.0.html

Vriendelijke groeten Ron

[phupper]

Thanks Ron,
I have wound a few motors with varying success, but am still confused by the formulas.

I found that the Axi 2808/20 is nearly identical to my 3530-10. It uses a 10t DLRK, so I'll wind mine with a 9t DLRK wind and try that.

I'm surprized there's not more data available on the configurations (polls, magnets, turns) of popular motor brands. Maybe learning the formulas makes that unnecessary.

Thanks!

Phil

[phupper]

I rewound this motor 4 times. I don’t have any way to test thrust or RPM, so I’m just going by current draw and prop size.

In case anyone’s interested, here are my results.

3530-10 BL Motor from HeadsUp RC
12 Poles 14 Magnets 25A 1000kv

Original 3530-10 Prop Data
AMPS PROP
15A - 8x6E
19A - 9x6E
20A - 10x5E

My Winding Data
Trys -Wire Gauge -- TPT -Wind -Turns -Amps -Prop -Term --Notes
1ST -1 strands #22 - 9 --DLRK --18 ---50A ---8x6E -Wye
2ND -5 strands #30 -11 - DLRK --22 ---7A ---10x5E -Wye
3RD -4 strands #30 -10 - DLRK --20 ---10A --10x5E -Wye
3RD -4 strands #30 -10 - DLRK --20 ---30A --10x5E -Delta -Gets Warm
4TH -5 strands #30 -11 - DLRK --22 ---28A --10x5E -Delta
4TH -5 strands #30 -11 - DLRK --22 ---25A ---8x6E -Delta -Close Enough

Phil

[flydiver]

I'm assuming the [10] designation for the motor is 10T. I'd be guessing at the gauge and strands. For that KV I'd hazard that it was Wye.

Was it a glued together mess? I'm always on the hunt for good candidates.

What is TPT? turns per tooth?

I find the 1at and 2nd tries having wildly different amp draws odd. There's a few more turns but that seems like a lot of discrepancy.
Also the 4th try dropping prop size pretty significantly only dropped 3A.

[phupper]

"I'm assuming the [10] designation for the motor is 10T. I'd be guessing at the gauge and strands. For that KV I'd hazard that it was Wye."

I'm not sure. I know Jeff at HeadsUp uses a different numbering system than most. I found no data for the original wind on the web.

"Was it a glued together mess? I'm always on the hunt for good candidates."

No not at all. It's assembled with set screws

"What is TPT? turns per tooth?"

Yes, I added that to avoid any confusion because it's a DLRK wind. So much for that idea.

"I find the 1at and 2nd tries having wildly different amp draws odd. There's a few more turns but that seems like a lot of discrepancy.
Also the 4th try dropping prop size pretty significantly only dropped 3A."

My bad. The first prop was 8x6 not 9x6 and second was a 10x5. Still that shouldn't make that much difference. It seemed odd to me too as I was testing it. Could be I made a mistake on the 7A wind. Also there's 2 ways to WYE terminate this motor, I don't remember which one I used (if that would even make a difference).

The 3530-10 is a good motor to begin with. The new wind with a 10x5 makes my GWS FW190 go vertical with ease.

Phil

[ron_van_sommeren]

Don't mix up your starts and ends of a wind, and how you connect them.

Vriendelijke groeten Ron

[phupper]

"Don't mix up your starts and ends of a wind, and how you connect them."

Could you elaborate on that Ron?

I'm still a bit confused on this, I've seen 2 ways to wye terminate.
1) Twist 3 adjacent wires together
2) Twist every other wire together

As I recall one of these is not recommended for 12 poles and 14 magnets.

Phil

[ron_van_sommeren]

Originally Posted by phupper

... 1) Twist 3 adjacent wires together ...

That would be 'star'.

Originally Posted by phupper

... 2) Twist every other wire together ...

That would be 'delta'.

Imagine you hooked up the phases correctly. Now switch the beginning end ending of one phase and hook it up again. That would be wrong, the voltage are not spaced 120 degrees anymore.

Originally Posted by phupper

... As I recall one of these is not recommended for 12 poles and 14 magnets...

Star is better, no recirculating currents due to possible differences in the phases.

Prettig weekend Ron

[phupper]

Ok, I was getting my facts mixed up.
As per the diagram below, WYE termination would be S1, S2, and S3 pigtailed together. Delta termination would be E2 and S1 twisted together, E3 and S2 twisted together, and E1 and S3 twisted together.


“... 1) Twist 3 adjacent wires together ...”

I think I saw that pattern for a different wind and 16 magnets.

Thanks!

Phil

[kyleservicetech]

phupper
Take a look at my article in Wattflyer per below: (Dry testing brushless motors)
http://www.wattflyer.com/forums/showthread.php?t=35216

Ron mentions "Getting your phases reversed". I built up 6 of the gobrushless motors, was very careful in getting the windings straight, still got two with reversed phases.

The above post covers shorting all three motor wires together, then rotating the motor slowly with a battery operated drill. If you've got a winding with reversed polarity, you will have very obvious "Chugging". Proper windings will have very smooth "drag".

If you've got a winding backwards, simplest way to find it short of an oscilloscope, is to mark all six wires from the three phases as 1,2,3,4,5 and 6. Reverse first 1,2, try the chugging test. If not, put 1,2 back in order and reverse 3,4. And if not, 5,6. If none of these are it, you've got a problem.

[phupper]

As it turns out, the battery I used for all those tests was weak. Now with a new battery things make more sense. I rewound to get the original 1000Kv and 25A using the data here:

Wire Gauge --TPT --Wind --Turns --Amps --Prop ----Term --Notes
1 strand #22 ---7 ------DLRK --14 -------25A ----11x5.5E -Wye ---Good Batt
1 strand #22 ---7 ------DLRK --14 -------20A ----10x5E ---Wye ---Good Batt

The single strand gives a better fill than the original multi-strand wind.
The motor runs great!

Phil

[Sparrowhawk]

Originally Posted by phupper

As it turns out, the battery I used for all those tests was weak. Now with a new battery things make more sense. I rewound to get the original 1000Kv and 25A using the data here:

Wire Gauge --TPT --Wind --Turns --Amps --Prop ----Term --Notes
1 strand #22 ---7 ------DLRK --14 -------25A ----11x5.5E -Wye ---Good Batt
1 strand #22 ---7 ------DLRK --14 -------20A ----10x5E ---Wye ---Good Batt

The single strand gives a better fill than the original multi-strand wind.
The motor runs great!

Phil

What determines the max continuous current? Wire gauge, stator, or magnetic flux (or a combination?)

I have this same motor & it has been sitting unwound for a while - I was wondering if I could turn it into a 1400kV 45A motor.

I haven't seen any discussion on this. Thank you for the great thread!

Dave

[kyleservicetech]

sparrowhawk
What determines the max continuous current? Wire gauge, stator, or magnetic flux (or a combination?)

As far as maximum current rating and corresponding temperature rise of the windings, it would be mostly the wire gauge, and just how effective the cooling system is for removing the heat from the windings.

[Sparrowhawk]

Originally Posted by kyleservicetech

sparrowhawk
What determines the max continuous current? Wire gauge, stator, or magnetic flux (or a combination?)

As far as maximum current rating and corresponding temperature rise of the windings, it would be mostly the wire gauge, and just how effective the cooling system is for removing the heat from the windings.

I'd assume the efficiency would drop quite a bit with an increase in current flow? Could it be so much so with this cheap motor that it might not be worthwhile to make a high current motor from it?

I'll give it a shot, but it is nice to talk to experts in the field.

[kyleservicetech]

sparrowhawk
I'd assume the efficiency would drop quite a bit with an increase in current flow? Could it be so much so with this cheap motor that it might not be worthwhile to make a high current motor from it?

Ah Ha
Maximum current rating is different from motor efficiency. I'm not a motor expert, but have rewound a number of brush and brushless motors over the past for to many years. Finally found that Hacker motors were far better than any I could ever make.

One item of concern on rewinding inexpensive motors is the quality of the stator steel laminations. The higher quality motors use much thinner laminations in the stator, and also use a much better grade of steel in these laminations.

The problem is, that any varying current value in the motor creates varying magnetic fields in the motor. These varying magnetic fields in them selves generates "short circuit current" in the steel laminations. Technical term is "eddy currents". That's why the stator with the windings is not made from a solid block of steel. Those steel laminations also have a very thin layer of insulation that separates each lamination from the other laminations, to reduce these eddy currents.

And, the faster you turn the motor, and the higher currents you apply to the motor, the higher these eddy currents become. And, the eddy currents, resistance losses in the copper windings, and also something called hysteresis in the steel laminations are all involved in efficiency.

[phupper]

"I have this same motor & it has been sitting unwound for a while - I was wondering if I could turn it into a 1400kV 45A motor."

I think you could rewind to get the 1400kv, but for 45A you may need a larger stator.

Phil

[Sparrowhawk]

Thanks much Kyle, that was an awesome intro to motors in that post

I'm usually turn and burn in an unstructured setting, so have not been extremely interested in how to compute efficiency. Till now I guess. I know Hacker and EFlight motors last forever, put out more power, and probably give longer flight times than the Turnigys or Tower Pros.

I am getting more interested in the minutiae of the hobby, which was why I'm interested in rewinding.

Dave

[Sparrowhawk]

Originally Posted by phupper

"I have this same motor & it has been sitting unwound for a while - I was wondering if I could turn it into a 1400kV 45A motor."

I think you could rewind to get the 1400kv, but for 45A you may need a larger stator.

Phil

Actually I was powering the 3530-1400kV at 42A with a 3S for about 7 or 8 flights. Till it spectacularly failed.

Maybe I'll try 20 gauge and 45A. Let's see what happens Thanks!

[ron_van_sommeren]

Originally Posted by Sparrowhawk

... which was why I'm interested in rewinding ...

Motor (re)winding 101, must read:
www.gobrushless.com/kb
-> basic overview (1-5)

Diy motor tips & tricks, checks and tests, may save you from frying your controller and/or newly wound motor.

More useful links in this thread, starting with this post:
http://www.rccanada.ca/rccforum/show...809#post586809

Vriendelijke groeten Ron

[son of alpea42]

Do you guys know how many turns a Eflight 370 1080kv?

[Sparrowhawk]

Originally Posted by ron_van_sommeren

Motor (re)winding 101, must read:
www.gobrushless.com/kb
-> basic overview (1-5)

Diy motor tips & tricks, checks and tests, may save you from frying your controller and/or newly wound motor.

More useful links in this thread, starting with this post:
http://www.rccanada.ca/rccforum/show...809#post586809

Vriendelijke groeten Ron

I've seen many of your posts, Ron; here and on RCGroups, thanks for taking the time to help newbies out. I guess I'll do some reading before I power up my new creation with an 11x7 I'm building a ViVi right now.

Dave

[warhead_71]

Chiming in... I need help rewinding a HeadsUp 3530-11. (I don't even see a 3530-10 at headsuprc.com... but this one is 1100kv - so maybe the same motor?)

http://www.headsuprc.com/servlet/the...lectric/Detail

When I took the old wire off I couldn't count the original number of winds... they were melted together. I think it was 7 strands of 30ga... but I could count the TPT.

I want to swing an 11x7 with as much ooomph as reasonable. I can just fit 10TPT of 22ga... but that seems like too many turns compared to your 7TPT for an 11x5.5 prop. I might try 8 or 9TPT... any suggestions?

[kyleservicetech]

Originally Posted by warhead_71

Chiming in... I need help rewinding a HeadsUp 3530-11. (I don't even see a 3530-10 at headsuprc.com... but this one is 1100kv - so maybe the same motor?)

http://www.headsuprc.com/servlet/the...lectric/Detail

When I took the old wire off I couldn't count the original number of winds... they were melted together. I think it was 7 strands of 30ga... but I could count the TPT.

I want to swing an 11x7 with as much ooomph as reasonable. I can just fit 10TPT of 22ga... but that seems like too many turns compared to your 7TPT for an 11x5.5 prop. I might try 8 or 9TPT... any suggestions?

Be sure to try out both "Y" and "Delta" winds on your motor. "Y" is when one lead from each winding is connected together, and the other three motor windings are connected to the ESC. "Delta" is connected all three windings "end to end", and those are connected to the ESC.

Delta winding will turn noticeably faster than "Y" connections, using the same exact windings in both cases.

Note that these windings do have to have correct polarity. This is noted in the thread listed below.
http://www.wattflyer.com/forums/showthread.php?t=35216

[warhead_71]

I plan to terminate WYE...

Wire Gauge --TPT --Wind --Turns --Amps --Prop ----Term --Notes
1 strand #22 ---7 ------DLRK --14 -------25A ----11x5.5E -Wye ---Good Batt
1 strand #22 ---7 ------DLRK --14 -------20A ----10x5E ---Wye ---Good Batt

Based on these results, I'm wondering if I need and extra wind for an 11x7. 8 turns of 22ga? I can fit 10... but that would decrease my KV. I could use multiple strands of 26ga or 30ga otherwise.