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Old Dec 26, 2012, 05:01 PM
Aka: Tom Jenkins
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Palm Beach County, Fl.
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Modisc and All,
Success! I tested as many wire combinations as I could figure, between each other, wire to stator then bundle to stator and tails etc as I went along. My optical tach bit the dust, I pulled out my trusty mechanical tach and get right at 8100 rpm on 12.35v, does this make it around 600 + Kv ? no load amps were 1.8 - CC180, 0 timing, 12Hz PWM - nano 2.2 65c 3s
Holly Cow , I grabbed the bell with a glove with slight pressure and read 3850 watts @ 30amps for a moment, that's on 3s!
Thanks Guys!
Tom
it ain't over neither,,,,,
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Old Dec 26, 2012, 10:16 PM
Jack
USA, ME, Ellsworth
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Sounds good, Tom! But 3850 Watts? I don't think so! 30A at 12V would be 360 Watts...

Jack
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Old Dec 27, 2012, 12:47 AM
Aka: Tom Jenkins
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Originally Posted by jackerbes View Post
Sounds good, Tom! But 3850 Watts? I don't think so! 30A at 12V would be 360 Watts...

Jack
Probably not, as that eflight meter only has one view at a time, that's what the batt read before I switched over, I'm just saying what I saw on 3s when grabbing the bell, pretty darnd powerfull!
fresh Endfest 300 with a bit of lint from the wind storm.
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Old Dec 27, 2012, 02:23 AM
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Congratulations Apex.
Very nice wind.

Manuel V.
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Old Dec 27, 2012, 08:52 AM
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Originally Posted by ApexAero View Post
Probably not, as that eflight meter only has one view at a time, that's what the batt read before I switched over, I'm just saying what I saw on 3s when grabbing the bell, pretty darnd powerfull!
fresh Endfest 300 with a bit of lint from the wind storm.
very nice job, but i still prefer your 2nd winding job.
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Old Dec 27, 2012, 05:08 PM
Aka: Tom Jenkins
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Originally Posted by modisc View Post
very nice job, but i still prefer your 2nd winding job.
I should rework the propellers I used, they got pretty chewed up and thin, also when I bent the nodes over it pushed some wire back a fuzz. I'll use a ball-peen the next time! lol I just finished gluing the wires and a wind storm with 30mph gusts blew lint and dust everywhere. Now to wind fast, neat and with precision!
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Old Dec 27, 2012, 07:16 PM
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I should rework the propellers I used, they got pretty chewed up and thin, also when I bent the nodes over it pushed some wire back a fuzz. I'll use a ball-peen the next time! lol I just finished gluing the wires and a wind storm with 30mph gusts blew lint and dust everywhere. Now to wind fast, neat and with precision!
Great work anyway. Looking at the coils, I cant think of that it will be burnt from excessive current ^^

Rewinding will be an enjoyment, if you can do a winding job like what you have done.
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Old Dec 28, 2012, 02:15 AM
Aka: Tom Jenkins
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Modisc, here's some nice motors!
http://slowflyworld.de/artikeldetail...3E+Scorpion+HK

Also I got 9500- 10000 rpm on 18.4v why is it so different with mor voltage?

Jack, pliers are ready.
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Old Dec 28, 2012, 04:23 AM
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Originally Posted by ApexAero View Post
Modisc, here's some nice motors!
http://slowflyworld.de/artikeldetail...3E+Scorpion+HK

Also I got 9500- 10000 rpm on 18.4v why is it so different with mor voltage?

Jack, pliers are ready.
Very nice looking winding job with flat wires. But as Powercroco tested, if i remember correctly, round wire can also be as good. I do not own an 45XX series scorpion, but I got a 4225 kit, and here is what i achieve: http://www.rcgroups.com/forums/showt...=4225+scorpion
original post in Chinese: http://bbs.5imx.com/bbs/forum.php?mo...91&pid=8228520

I used 1.4mm wire, and achieved 13T (6+7) using standard STSD technique. copper fill in one slot is : 1.4 X 1.4 X3.14 X 13 / 4 = 20mm^2.

The best on the link you provided for 45XX stator is 22.8 mm^2.

A rough comparison is that for my 4225, converting to 45XX: 20X 45X45/42/42 = 22.96 mm^2.

For flat wires, the wires size has to be very fit to the slot size, to achieve a good copper coverage: for example, the tooth length need to be multiple of the length of the cross section of the wire.

These flat wires looks nice though ^^. But I still prefer round wires. With proper wire size, using STSD, very amazing copper fill can be achieved.
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Old Dec 28, 2012, 08:12 AM
Jack
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Originally Posted by ApexAero View Post
Modisc, here's some nice motors!
http://slowflyworld.de/artikeldetail...3E+Scorpion+HK

Also I got 9500- 10000 rpm on 18.4v why is it so different with mor voltage?

Jack, pliers are ready.
OK, I'll PM you on the details...

Jack
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Old Dec 28, 2012, 03:21 PM
Aka: Tom Jenkins
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Palm Beach County, Fl.
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Modisc,
I still have the technical question to ask and need your input. when I test the new motor on 18.6v I get around 9500 rpm, 12.4v it gets 7812 rpm, I use a mechanical tachometer for testing, CC180, 0 timing, 12Hz PWM. What are your Kv predictions?
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Old Dec 28, 2012, 03:53 PM
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Modisc,
Still have the question as to when I got 9500- 10000 rpm on 18.4v and why the reading for Kv is it so different with more voltage?
I dont follow. Comparing with what, you say "so different"?

If you mean calculated Kv based on rpm / voltage is different, if you change the input voltage, then it is normal as

Motor RPM

RPM = Kv * (V - Vloss)
Vloss = Iin * Rm


http://www.rcgroups.com/forums/showthread.php?t=587549

If you mean your scorpion's Kv is very different from scorpion factory's 11T 4035 12N10P, then what I experience is that for 12N8P HK 40XX scorpion factory motors, if it is labelled 10T, then it should be viewed as 12T, due to factory winding issues. I am not very sure the same thing happens for 12N10P motors.
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Old Dec 28, 2012, 05:51 PM
Aka: Tom Jenkins
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What I mean is on the new motor I'm trying to access the Kv value and get two numbers from two tests, their not even close!
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Old Dec 28, 2012, 06:25 PM
Jack
USA, ME, Ellsworth
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Originally Posted by ApexAero View Post
Modisc,
I still have the technical question to ask and need your input. when I test the new motor on 18.6v I get around 9500 rpm, 12.4v it gets 7812 rpm, I use a mechanical tachometer for testing, CC180, 0 timing, 12Hz PWM. What are your Kv predictions?
Looks to me like the Kv is somewhere between 510 and 630 by just dividing the RPM by the volts.

You want read the both the voltage and RPM while at full throttle. I get them bot simultaneously with an eLogger but even if you had to go to full throttle and read one, then stop and do it again to read the other, that should give you good numbers. The higher the voltage the higher the no load RPM of course but the Kv's should stay similar.

Jack
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Old Dec 28, 2012, 10:10 PM
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Originally Posted by ApexAero View Post
What I mean is on the new motor I'm trying to access the Kv value and get two numbers from two tests, their not even close!
like Jack said. You must measure full throttle no load rpm, of course....Kv should be very close by only changing the voltage using the same ESC.
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