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Old Oct 06, 2012, 05:17 AM
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Do you have a ling to that calculator?
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Old Oct 06, 2012, 06:22 AM
Jack
USA, ME, Ellsworth
Joined May 2008
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This is the link to it that was working up until yesterday:

http://www.powerditto.de/bewicklungsrechner.html

But you may get a 404:Page not found error on it right now. I went to the home page for that site: http://www.powerditto.de/ and is still there, when I google translated ir, the home page says that "..Due to maintenance and renovation work, the page is temporarily unavailable!..."

So I'm sure it will be back soon. Hopefully.

If you are using the upper and lower case winding scheme notations like A-b-C-a-B-c- you have to be careful when you use google to translate those pages. It does not understand the significance of the upper (CW) and lower (CCW) letters and will not get those right sometimes.

It took me a while to get comfortable with using that page but once I realized that it is always technically correct and also gives you some additional info about the winds, I pretty much stopped using anything else.

I got that re-wound again last night but social commitments kept me from getting any further. But it will be up and running again soon!

Jack
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Old Oct 06, 2012, 09:08 AM
homo ludens modellisticus
Ron van Sommeren's Avatar
The Netherlands, GE, Nijmegen
Joined Feb 2001
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Quote:
Originally Posted by jackerbes View Post
... If you are using the upper and lower case winding scheme notations like A-b-C-a-B-c- you have to be careful when you use google to translate those pages. It does not understand the significance of the upper (CW) and lower (CCW) letters and will not get those right sometimes. ...
The winding diagram calculator is available in English Jack. Just select 'en' instead of 'de' (dzjerman a.k.a. deutsch ).

Prettig weekend Ron
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Old Oct 06, 2012, 09:35 AM
What goes up must come down..
Canada, QC, Saint-Laurent
Joined Jan 2002
1,724 Posts
Ron,
How can i access that page?
I got still this all the time on the link:

http://www.powerditto.de/bewicklungsrechner.html

Error 404: NOT FOUND!
This domain name has just been registered.

This homepage was created automatically when you registered your 1&1 domain package or hosting package. This homepage is only temporary and can be replaced with a website you create at any time (please refer to point 3 below).

3. How can I create my own site?

A detailed description of how to create a homepage can be found in the 1&1 Help-Center. The MyBusiness Site offers a particularly easy and comfortable way to create your own homepage. You choose from over 125 business sectors templates and create your internet presence in just a few clicks. Try it for free.

so strange..I need help. I don't want to create a home page I just what to access the info's.

Roger
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Old Oct 06, 2012, 10:05 AM
Jack
USA, ME, Ellsworth
Joined May 2008
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Quote:
Originally Posted by Ron van Sommeren View Post
The winding diagram calculator is available in English Jack. Just select 'en' instead of 'de' (dzjerman a.k.a. deutsch ).

Prettig weekend Ron
I knew that, Ron. Been using it that way all along. And I am really glad that they take the trouble to do that.

But some of the German does not translate when you choose English. And there are some pages on the croco and ditto pages where google translating them will screw up those schemes. It is sort like it wants to see that as the first word in a sentence or proper noun and start it with a capital but won't follow the original pattern.

Jack
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Old Oct 06, 2012, 10:08 AM
Jack
USA, ME, Ellsworth
Joined May 2008
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Quote:
Originally Posted by rodair View Post
Ron,
How can i access that page?
I got still this all the time on the link:

Error 404: NOT FOUND!
This domain name has just been registered.

This homepage was created automatically when you registered your 1&1 domain package or hosting package. This homepage is only temporary and can be replaced with a website you create at any time (please refer to point 3 below).

3. How can I create my own site?

A detailed description of how to create a homepage can be found in the 1&1 Help-Center. The MyBusiness Site offers a particularly easy and comfortable way to create your own homepage. You choose from over 125 business sectors templates and create your internet presence in just a few clicks. Try it for free.

so strange..I need help. I don't want to create a home page I just what to access the info's.

Roger
I'm sure it'll be back eventually. They took it down to work on or something. Probably making it better for us!

I'm not sure that what I said above about the unbalanced wind is correct or not and I may be off target here. But I'll stay with what is working good for now.

I just finished the 4S testing on the rewind and it almost scaring me!

Jack
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Old Oct 06, 2012, 10:42 AM
Jack
USA, ME, Ellsworth
Joined May 2008
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OK, got that rewound and terminated again. It is running as well as or even better than the first I think, seems a little smoother and quieter.

19 turns with Tech Fixx 21 AWG wire, LRK A-b-C-a-B-c-, and Wye termination.

no load = 7498 @ 9.29 = 807 Kv
noload = 9499 @ 11.92 = 797 Kv

So I'll still think of it as a 800 Kv motor. Used a 5S A123 2300 mAh pack for 4S voltages and a 7AH sealed lead-acid battery for 3S voltages. I am sneaking up on things a little in view of the sparks and smoke last time...

APC TE 12 x 6 on 3S

4 seconds @ 1,410 RPM, 12.09V, 0.54A, 7W temp 68F to 69F
9 seconds @ 2,521 RPM, 11.94V, 1.35A, 16W temp 68F to 69F
17 seconds @ 3,440 RPM, 11.73V, 2.64A, 31W temp 69F to 70F
9 seconds @ 4,595 RPM, 11.38V, 5.63A, 64W temp 69F to 71F
then to full throttle
40 seconds @ 5,540 RPM, 10.85V, 9.97A, 108W temp 70F to 74F

4S testing

19 seconds @ 2,764 RPM, 17.67V, 1.24A, 22W temp 71F to 74F
18 seconds @ 3,375 RPM, 17.33V, 1.90A, 33W tem 71F to 73F
23 seconds @ 4,216 RPM, 16.77V, 3.28A, 55W temp 74F to 74F
29 seconds @ 4,924 RPM, 16.33V, 5.19A, 85W temp 72F to 74F
31 seconds @ 5,955 RPM, 15.72V, 9.22A, 145W, temp 74F to 77F

motor was allowed to cool, then did a full throttle run

51 seconds @ 6,354 RPM, 15.43V, 11.39A 176W, temp 70F to 79F

there was some impression that the last few click of throttle travel was not adding to the RPM so I backed off the throttle until motor slowed a little, then took back up until RPM peaked. At that point I was about 2-3 click back from full throttle:

15 seconds @ 6,083 RPM, 15.30V, 10.03A, 153W temp 79F to 81F

Those numbers are the averages for the stated durations. On the full throttle run the A123 cells were down around 3.06V which is perfectly normal for them. With a decent quality 4S LiPO pack (I don't own one) the voltage would have held a little higher.

So this motor does not get the RPM that Trug's 780 Kv Half Parallel dLRK wind did out of that same prop. His reported numbers were

APC 12x6e on Impulse 4s3000 battery - 8, 370 RPM, 13.72V, 28.73A, 68.5 oz. thrust

But I am somewhat amazed in that the LRK wind is doing what it did on 10A of current and is barely even warm yet. Looks to me like a 5S LiPO would have this motor probably equaling Half Parallel dLRK wind and doing it with a lot less current and battery capacity.

My biggest prop is the APC 14 x 10, I'll spin that one up eventually too and see what that does to the numbers.

I've got to build a plane for this motor, and I'm thinking it needs to be bigger than anything I've built recently.

Jack
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Last edited by jackerbes; Oct 06, 2012 at 12:58 PM. Reason: correct turn count
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Old Oct 06, 2012, 09:31 PM
low tech high tech
vtdiy's Avatar
Southern Vermont
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Rodair, check your spelling of the site address.
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Old Oct 07, 2012, 01:53 AM
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manuel v's Avatar
Mexico, BC, Mexicali
Joined Aug 2004
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Jack
I think this motor is not suitable for your purposes, driving a propeller 14x10 to good efficiency.

Input putting only 19 turns 21AWG LRK, Vs 18 turns of 22AWG DLRK.
There is a big difference in capacity of copper to favor DLRK.

This makes the engine unduly inefficient.
It's like to rewind 18Turn 25AWG DLRK motor.

Full throttle motor gives the numbers below 60% NLS, or very few revolutions per volt.
Typically this motor is above 74%. when in DLRK.

For a 14x10 APC to the Kv should 3slipo walking about 650 and about 580 4s lipo. but possibly would benefit from improved efficiency with between 50 and 80 Kv less
But in wind DLRK.
This engine does not have enough separation between stator and front bell for wind in LRK.

I think.

Manuel V.
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Last edited by manuel v; Oct 07, 2012 at 02:16 AM.
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Old Oct 07, 2012, 02:02 AM
Dave North
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USA, CA, San Jose
Joined Apr 2004
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Sounds right to me also, Manuel.

Dave
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Old Oct 07, 2012, 06:31 AM
What goes up must come down..
Canada, QC, Saint-Laurent
Joined Jan 2002
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Jack,
that was fast and nice rewind + already with results that even better!

Thanks for sharing these, as for the upper limit clicks that doesn't do much in change of te RPM, I think I had to bind once with the throotle stick @ WOT (without prop) that brimg ot back to zeo turn off everthing re-install the prop and that cure the problem on an EFLT 30A esc..

Manual and Dave thanks for coming in you had so much good results with DLRK windings, I guess I'll order some wires and redo one this winter, but neverless I am impress Jack on how low the amp ~12 A turning an APC TE 12 x 6 on 3S @ 6,354 RPM and having only 81F recorded that leading to 176 Watts!

I have no idea on how much thrust this motor would do on a little Bipe (570 gr.) and with the prop I have suggested to you PKZ1005 or with an APC 11 x 5.5e or 11 x 7e on 3S 2200 mAh max.?

The possibility to run lower weight 3S LIPO (133 gr.) and smaller 30A ESC (37gr) with std. 3,5 mm connectors and wires for longer time on smaller ships and still having the ground clearance for the prop when I land with low temp. for the bearing inside are for sure all + so close to 200 Watts pulling 18A possible with LRK winding and 1:1 thrust no?

I am close with my "frankenstein look" winding of 2 wires #24 AWG 18 Turns LRK Y any I have 300 flights + logged with it and had one set of bearing changed so far + one ESC due to miss handling.

I fly a lot, 3S lipo @ 1300 to now 1500 mAh, are the "weight target" for my ship and equipement I already own using the DAT motors on all my planes is now std. and it was my first time at rewinding, thanks to you, with some success.

So if you can try for me, I know it sounds "egoistic", some 11" dia. props and post some results I can then see if this wouldn't be close to an ideal winding for me and that would be LRK for easy winding, less than 16 Amp @ WOT with a 10" x 8 -11"x 8 prop size on 3S 1500 mAh lipo, your's the way it is, sound close to this give or take few turns.

It is always interesting to read you all here! I hoping to fly this afternoon weather permit and have some fun.

Roger
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Last edited by rodair; Oct 07, 2012 at 07:20 AM.
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Old Oct 07, 2012, 07:18 AM
Jack
USA, ME, Ellsworth
Joined May 2008
17,138 Posts
I guess I don't know enough about motor efficiency. I better go off and study that some. I have never looked at efficiency at all when I rewind motors and those graphs make my head hurt a little.

I'll start here...

http://www.peakeff.com/Default.aspx

"..This engine does not have enough separation between stator and front bell for wind in LRK..."

The mechancal clearance between the windings now (inside, widing to bell) is about 3mm. It is about the same as with the factory wind or even a little more.

Jack
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Old Oct 07, 2012, 08:11 AM
Jack
USA, ME, Ellsworth
Joined May 2008
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Quote:
Originally Posted by rodair View Post
Jack,
that was fast and nice rewind + already with results that even better!

Thanks for sharing these, as for the upper limit clicks that doesn't do much in change of te RPM, I think I had to bind once with the throotle stick @ WOT (without prop) that brimg ot back to zeo turn off everthing re-install the prop and that cure the problem on an EFLT 30A esc..
I don't think it was a calibration issue, more that the prop and power had matched and there was no perceptible RPM gain.

I usually calibrate the throttle on the Phoenix 80 I'm using each time I power up. That is just a case of starting with the throttle partially open, then going to full, and then back to closed. The ESC then uses those full and zero endpoints.

Quote:
..I guess I'll order some wires and redo one this winter, but neverless I am impress Jack on how low the amp ~12 A turning an APC TE 12 x 6 on 3S @ 6,354 RPM and having only 81F recorded that leading to 176 Watts!
I guess my ignorance of efficiency is making me happy with something I should not be happy with. It will be good for me if I can come to grips with the all of those numbers and graphs and better understand motor efficiency.

Quote:
I have no idea on how much thrust this motor would do on a little Bipe (570 gr.) and with the prop I have suggested to you PKZ1005 or with an APC 11 x 5.5e or 11 x 7e on 3S 2200 mAh max.?
I don't measure thrust so, when I am curious about it, I have been using the prop data at flybrushless.com to estimate thrust. And your HZ prop is not in there. Maybe I'll send that prop on to Dr Kiwi (if he wants to have it) and it will eventually get some data into the tables there

Quote:
The possibility to run lower weight 3S LIPO (133 gr.) and smaller 30A ESC (37gr) with std. 3,5 mm connectors and wires for longer time on smaller ships and still having the ground clearance for the prop when I land with low temp. for the bearing inside are for sure all + so close to 200 Watts pulling 18A possible with LRK winding and 1:1 thrust no?
Bearing overheating has not been an issue for me as much as the bearing simply wear out quicker and damage easily due to their smaller size. I just keep them lubricated and replace them when I think they are getting noisy and worn. They are cheap enough...

Quote:
I am close with my "frankenstein look" winding of 2 wires #24 AWG 18 Turns LRK Y any I have 300 flights + logged with it and had one set of bearing changed so far + one ESC due to miss handling.
I realize now that your wind is almost exactly the same as mine. Two strands of #24 (0.205 mm2 x 2 = 0.410 mm2) has the same surface area as does one strand of #21 (o.410 mm2). So the only difference in our motors is that yours has two strands and one turn less. So it has a little higher Kv, maybe 840 or 850 or so.

Quote:
..<snip>... So if you can try for me, I know it sounds "egoistic", some 11" dia. props and post some results I can then see if this wouldn't be close to an ideal winding for me and that would be LRK for easy winding, less than 16 Amp @ WOT with a 10" x 8 -11"x 8 prop size on 3S 1500 mAh lipo, your's the way it is, sound close to this give or take few turns.
I think since you have the props you should just get some wire, explore this, and report back here. I say that with no mean spirited intent, it is going to be your first hand impressions that will decide the best deal for you. And if the experts think you or I should not be enjoying this wind we can just ignore them!

If I reduced the turn count and raised the Kv some, in theory, I could get more RPM out of this motor with props in the size range you mention. Maybe that is what you or I should do? I've almost used up my spool of Tech Fixx green 21 AWG wire, I'll order the amber (not the red) wire next time because it has a higher temp rating (200C) than the green (155C). I think the coating on the amber is a little tougher too.

I've been just running the props I happen to have and looking at them from the view point of how I use them. I gave Manual the impression that I wanted to fly with an APC 14 X 10 and that is not the case. It was just a bigger load that I had on hand. I have not been flying the bigger APC TE props at all since the planes those were used on (the SIG Rascal 40 and the Coroplast SPADet) went away. Almost everything I fly gets a Great Planes slow fly except for the folders on the gliders.

Jack
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Old Oct 07, 2012, 08:30 AM
homo ludens modellisticus
Ron van Sommeren's Avatar
The Netherlands, GE, Nijmegen
Joined Feb 2001
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Quote:
Originally Posted by jackerbes View Post
... I have never looked at efficiency at all when I rewind motors ...
Don't sell yourself short Jack, you are too modest a guy apparently You have looked at efficiency, all the time. Because right from the start of your motor (re)winding career, your cared about maximum power and maximum current

Efficiency governs power/weight ratio
Higher efficiency does not only mean that the motor makes better use of the batteries' power, it also means the motor is able to handle a higher power input before hitting its maximum temperature mark i.e. a the power/weight ratio will be higher.

An example
Say the motor has an efficiency of 70% and it can handle 50Watt input. That means it can get rid off 30%*50=15Watt excess heat. Now, by cramming in thicker wire (and/or using better stator-iron, segmented magnets), efficiency increases to say 75% (I'm a bit optimistic here). The motor's ability to loose those 15Watts has not changed (by radiation, convection and conduction). This means the motor now can handle 60Watt before it hits the 15Watt (25%*60Watt) losses mark. An efficiency increase of 5% gives an increase in the power to weight ratio of 20% (from 50Watt to 60Watt). That's why efficiency plays such an important role, in any motor design: efficiency governs maximum power. The motors weight may have increased a bit due to more copper.
A rather extreme example, just for calculation's sake/fun: going from 80% to 90% efficiency would increase the input power the motor can handle by a factor two (a.k.a. 2).
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Old Oct 07, 2012, 08:38 AM
Jack
USA, ME, Ellsworth
Joined May 2008
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Thank you! I am beginning to see the light already!

I think that is the explanation that I needed to get started with.

Jack
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