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Old Jan 18, 2011, 01:51 PM
Expo is built into my thumbs
Hance's Avatar
USA, ID, Niter
Joined Jul 2008
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Originally Posted by Truglodite View Post
Last time I checked, they came with a random mix of 9 and 10T stator poles (sometimes all have 10T... factory morale must change day to day), 4strand, 32awg trashwire (the stock choice for chinese multistrand winds), wound using the delta variant dLRK, and terminated delta. Let us know if there's glue on those wires please.

Kev

Glue on the wires ? As in glue holding the wire to the stator ?
I am about to make another hobbyking order its an addiction of mine. When I do I am going to get a couple of the Turnigy 2730 3000kv motors. I like the turnigy branded motors better than the no name ones they seem to be a little more durable in my experience.
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Old Jan 18, 2011, 01:58 PM
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Carmichael, CA
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Originally Posted by Hance View Post
Glue on the wires ? As in glue holding the wire to the stator ?
Yep... sorta. They have been using CA to hold the wires on (not just 3000Kv, lately the ABC winds have been coming glued too). The goal is to tack the last turns on with just enough glue so they don't pull loose; I do this on many of my 3-layer winds... I apply a small dot of black CA (about as thick as medium CA) where the termination lead pops out, and kick it with accelerator so it doesn't capillary in... accelerator also prevents fogging . The dot of glue keeps 3-layer winds from popping out up front or looping over the top of the hammer (sometimes a dot up front on top is needed to prevent looping), and it easily pops off with no stator residue if repairs are needed later on. The other benefit is the tighter windings vibrate and chafe a lot less than looser windings. The problem with the stock motor glue: at the factory they apply a heavy coat of thin CA and don't use accellerator (doesn't look like it anyways). So the CA ends up seeping though and getting all over the stator. This means cleaning/scraping work if you're shooting for a more packed wind. Some take more time to clean than others.

Kev
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Old Jan 18, 2011, 02:06 PM
Expo is built into my thumbs
Hance's Avatar
USA, ID, Niter
Joined Jul 2008
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Quote:
Originally Posted by Truglodite View Post
Yep... they have been putting CA to hold the wires on (not just 3000Kv, lately the ABC winds have been coming glued too). They usually goop it on so it ends up seeping though and getting all over the stator; this means cleaning/scraping work if you're shooting for a more packed wind.

Kev
Just poking and prodding the windings I am inclined to say yes they are glued. I don't know if I will rewind these motors or not. I really need to test their performance out with a 3s pack and a 4.75X4.75 prop on my adrenaline rush and see how they do. If they aren't blindingly fast then they are getting rewound.
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Old Jan 18, 2011, 02:10 PM
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United States, WI, Avoca
Joined Dec 2003
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Glue on Wires and a Question Relating

One of the guys in our club had/has two motors that came from HK. They both are 3530-11 with 12 stators and 14 magnets and posted as 1100kv
They both burned up one phase. They came wound with the "trash" wire multi-strand wire, and yes they had glued wires in them. They come with the base and pedistal as one unit, so I had to heat it up to get the stator group off. That really made a mess, as the glue melted, then re set when cooled. I tried to re-wind one of them so far, and the edges of the stators are sharp, and seem to cut through the insulation (shellac) real bad. I have tried different guages of wire and #of turns, and they all come up with at least one phase shorted to the stator. So far I have tried four times. I quit.
Any help, please ?
Prop s. aka Gary
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Old Jan 18, 2011, 02:15 PM
Expo is built into my thumbs
Hance's Avatar
USA, ID, Niter
Joined Jul 2008
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Originally Posted by Prop stitches View Post
One of the guys in our club had/has two motors that came from HK. They both are 3530-11 with 12 stators and 14 magnets and posted as 1100kv
They both burned up one phase. They came wound with the "trash" wire multi-strand wire, and yes they had glued wires in them. They come with the base and pedistal as one unit, so I had to heat it up to get the stator group off. That really made a mess, as the glue melted, then re set when cooled. I tried to re-wind one of them so far, and the edges of the stators are sharp, and seem to cut through the insulation (shellac) real bad. I have tried different guages of wire and #of turns, and they all come up with at least one phase shorted to the stator. So far I have tried four times. I quit.
Any help, please ?
Prop s. aka Gary

Well thats just lovely. Guess what the other motor was in my hobbyking order. Yup the SK3530-1100 to put in my stevens aero groove 480.
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Old Jan 18, 2011, 02:19 PM
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Carmichael, CA
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Originally Posted by Prop stitches View Post
the edges of the stators are sharp, and seem to cut through the insulation (shellac) real bad.
Any help, please ?
Prop s. aka Gary
Apply a thin coat of black CA to the sharp exposed metal on the corners of the stator... use accelerator. If you accidentally goop too much on, it can be easily shaved with an x-acto. That should get you fixed up.

Kev

[edit: The other option is to wrap the stator poles with "fish tape"... if you can find it. I've also used kapton tape, but black CA is just easier.]
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Old Jan 18, 2011, 09:33 PM
Expo is built into my thumbs
Hance's Avatar
USA, ID, Niter
Joined Jul 2008
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Well I just hooked mister Eagle Tree up to my adrenaline rush with the custom wound 4500kv blue wonder. spinning a 4.75X4.75 prop on 2s I am getting 25,232 rpm. Thats a pitch speed of around 113 mph on a 24 inch wingspan plane.
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Old Jan 22, 2011, 01:18 AM
Foam, foam on the range....
didge's Avatar
Adelaide, Australia
Joined Feb 2009
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Originally Posted by Hance View Post
I am getting a little bit better but wow this is the sickest by far I have ever been from the flu

So people were wondering about the wind termination etc for the motors I ordered. Can you help a dummy out and tell me how figure it out ? Or is it easiest to just post photos ? I have rewound a few but I am really a beginner when it comes to this. Holiday today so I couldn't get the motors from the post office hopefully tomorrow I will be able to go get them first thing.
Sorry Hance, I missed this post. Good to see you're up and about again!

It's not the termination scheme I was wondering about - (DLRK and ABC can be either delta or wye), it's really just the magnet count that matters, 14 or 16. As these motors have 12 stator arms, 16 mags will be ABC, and 14 mags will be DLRK. Anyway, good to hear that they're still DLRK! Thanks.

Cheers
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Old Jan 22, 2011, 08:36 PM
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Originally Posted by Truglodite View Post
Apply a thin coat of black CA to the sharp exposed metal on the corners of the stator... use accelerator. If you accidentally goop too much on, it can be easily shaved with an x-acto. That should get you fixed up.

Kev

[edit: The other option is to wrap the stator poles with "fish tape"... if you can find it. I've also used kapton tape, but black CA is just easier.]
Thank You, Truglodite, I will deffinately do the CA trick. I have wasted enough wire already.
Prop s.
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Old Jan 24, 2011, 06:19 AM
Winging it >
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Joined May 2006
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part throttle efficiency

I have a Tricopter which uses three BW motors. I used 1500 kV motors since that is what I had and it is the motor I use on most of my small planes.

For the Tricopter I'm pretty sure a lower kV motor is going to give me longer flights. With the 1500 kV motors, lift greatly exceeds weight. The flying weight with a 1000 3s battery is 550 grams, so each motor/prop only has to produce about 180 grams of thrust.

Question #1: At part throttle will I see much improvement with a low kV rewind vs a stock 1300 kV motor? I'm trying to decide between buying some 1300's (lazy choice) or rewinding three motors.

Quesiton #2: Is there any efficiency gain going to 2s when deciding between 2 batteries with the same total energy... example 1000 3s vs 1500 2s assuming the 2s still provides the thrust required for hover? In both cases the thrust is the same; enough for hover.
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Old Jan 24, 2011, 10:39 AM
Dave North
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The answer to Question 1 is not so simple. Generally you'll see better efficiency as you approach full throttle, but how much at any given point is a fairly complex function. Short answer: I don't know.

The 2S vs 3S issue is tricky. If you're using the BEC, the voltage drop for 2S is smaller than 3S, so you get an efficiency gain there. Weirdly, and counter to what's logical, we often see better efficiency from 2S motors than 3S (though peak power is usually lower). This is less surprising than meets the eye. While it's true that the same wattage at a higher voltage will come with lower resistance, it's also true that the winding for a 2S motor headed for similar RPM will have lower internal resistance. The 3S should be better, but often it does not test out that way.

This is usually not a huge number either way.


Dave
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Old Jan 24, 2011, 12:54 PM
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Originally Posted by timocharis View Post
The answer to Question 1 is not so simple. Generally you'll see better efficiency as you approach full throttle, but how much at any given point is a fairly complex function. Short answer: I don't know.

The 2S vs 3S issue is tricky. If you're using the BEC, the voltage drop for 2S is smaller than 3S, so you get an efficiency gain there. Weirdly, and counter to what's logical, we often see better efficiency from 2S motors than 3S (though peak power is usually lower). This is less surprising than meets the eye. While it's true that the same wattage at a higher voltage will come with lower resistance, it's also true that the winding for a 2S motor headed for similar RPM will have lower internal resistance. The 3S should be better, but often it does not test out that way.

This is usually not a huge number either way.


Dave
Thanks Dave.

I'm going to try and test a few different motors at the thrust level I need to see how they compare. I'll report back.
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Old Jan 24, 2011, 07:42 PM
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Dave, factor in the differences in Io*V, and it gets even worse. Regarding efficiency vs throttle... my test spreadsheets are capable of easily fitting a curve to efficiency vs throttle, but only a few of my tests actually include partial throttle data. I suspect that the equations for that curve will vary a lot; prop size, max rpm... just think how bad it could get.

I haven't had a project where 2s & 3s were both usable, and thumbing through my data I found no tests that would shed light on this subject. Looking forward to seeing your results leadfeather.

Kev

[edit: leadfeather, since you're using this on a quadcopter, you want to maximize efficiency at the exact RPM where lift=weight... leaving excess some amount of thrust to climb/recover. Perhaps designing the motor to reach a lower excess thrust will mean greater efficiency at hover... the limit being that there's enough thrust to recover from an emergency. How much (%wise) excess thrust is necessary? This subject is fairly new, and lots of testing can be done to further the quadcopter cause.]
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Old Jan 24, 2011, 08:34 PM
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Test data

I did my very first motor/prop testing. I built a really simple test rig that seemed to work well. The thrust measurement was very steady. The volts and amps were bouncing around a bit, I did my best to get good average readings.

I tested two motors. The first is a stock 2730-1500 Black and Red wonder. The second is a Blue Wonder rewound by Mike Bergy at 1050 kV. All results were measured at 200 grams of thrust steady state.

I tested the props I had on hand that were reasonable to test with these motors.

Results:

1) Stock 2730-1500 Black & Red

..Watts..Prop used

30.8 ..... GWS 8043
30.3 ..... GWS 8040
30.0 ..... GWS 9050
30.1 ..... Haoye 1047
40.1 ..... GWS 1147

2) Bergy 1050 BW

23.0 ..... GWS 8043
22.8 ..... GWS 8040
22.1 ..... GWS 9050
21.8 ..... Haoye 1047
24.5 ..... GWS 1147

Based on these results the kV has a major impact on efficiency for this part throttle test. The lower kV shows significant power saving for the same thrust.

The prop is also important but to a lesser degree.

In all cases there was excess power/thrust available if I advanced the throttle.

OK, now I need three low kV motors for my Tricopter! Any motor winders out there for hire?
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Old Jan 25, 2011, 07:25 PM
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Found these 1000 kV BW's for $13.
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