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Posted by timocharis | Mar 04, 2010 @ 05:13 PM | 5,748 Views
Somebody sent this in the hopes I could save it. Not really sure I did (the mechanicals are less than ideal) but it does have some distinctions:

Thickest wire I've used: 17 awg.
Fewest turns: 4
Lowest Rm: 0.0061

Not sure if it's the highest Kv @ 3620. I'd have to go through the records. But it probably is. Look close and you'll see some kapton -- the stator insulation is horrid. I've only seen this crud on one other stator, and it cracked and exfoliated there too.


Dave
Posted by timocharis | Jun 13, 2009 @ 03:34 PM | 7,441 Views
After the excellent 20-turn result, I had to see if I could sneak on one more turn. Would the result be anywhere near as good?

Yup!

Tgy 21T 26g ABC Delta Kv 1435 Io = 0.61 Rm = 0.150
GWS 8040 Rhino 460 3S
10610 rpm @ 10.49 volts, 9.10 amps
Badcock: 577 grams 20.4 oz/thrust 80.3% Efficient
DriveCalc: 636 grams 22.4 oz/thrust 82.5% Efficient

That's some pretty serious power from such a small motor and battery, but even weirder at such a pleasant efficiency range. Gotta see what's possible dLRK, since I personally prefer that setup. But I doubt I can match this.
Posted by timocharis | May 20, 2009 @ 12:50 AM | 7,415 Views
Been meaning to put this up for a while. Pete wanted to shoot some shots that day, so I did a rolling circle by him. I guess I needed to get pretty angry at the plane -- okay, it's probably just concentration, but sheesh. The thing I like about it is he snapped the shot at one of those rare moments where I actually had all the control surfaces in the right place, and it looks like I actually know what I'm doing. Neat illusion!
Posted by timocharis | Aug 13, 2008 @ 02:07 AM | 9,443 Views
Another dang motor on the internet.

Been rewinding the little Hex 16-gram motors for some guys at the field -- we're into full-contact wing wars now. Foam abuse indeed!

So far, these are probably the top contenders for a power plant. It's an ABC motor with 11 turns of 24awg. Not an especially hard wind at all, and I think 23awg would fit but only if I go to a third layer. However, the motor won't tolerate it because the bell sits too close to the stator.

Ultimately it means the wires end up very, very neat. And there's something to be said for that.
Posted by timocharis | Jul 12, 2008 @ 01:44 PM | 9,741 Views
Last week's 12-turn is somewhat analogous to the dLRK 13-turn. Which implies that a little more efficiency could be scraped from the bottom of the barrel by adding one turn.

So of course I had to try a 13-turn. And of course, another record is set:

Hex 13T 24g ABC Wye Raw Kv 1335 (15889/11.92) Io = 0.61
GWS 8040 HD Tp 730 3S
9795 rpm @ 9.95v/7.37a 489 grams 17.2 oz/thrust 81.5% Efficient

Still strong at even higher power levels:

GWS 8040 HD Hex 620 3S
10362 rpm @ 10.83v/8.28a 549 grams 19.4 oz/thrust 79.4% Efficient

So there you have it. Either one is a great performer, but over 81% is worthy of note I think. Plus, the lower input of a 500 MAH-class battery means this motor is probably safe to run with that size.

Just for reference, that's over five efficiency points and two ounces better performance than the stock Blue Wonder.
Posted by timocharis | Dec 19, 2007 @ 10:05 PM | 10,427 Views
I suppose I'll just record the records as they fall. This one was completely unexpected -- just pursuing an earlier experiment. Tried for a neat, flat layout 12-turn 24awg ABC wind to see if it would at least duplicate an earlier effort that required a half-loop displacement to get the wire on.

Some reading I've done lately implied that neatness actually does count. Maybe not a lot, but having two neat layers apparently offers some advantages in the nature of the flux->magnet interaction.

Woohoo, something went right!

Hex#2 12T 24g ABC Wye Raw Kv 1435 (17201/11.99) Io = 0.73
GWS 8040 HD Tp 730 3S
10158 rpm @ 9.87v/8.39a 527 grams 18.6 oz/thrust 80.8% Efficient
GWS 8040 HD Hex 460 3S
10795 rpm @ 10.81v/9.43a 598 grams 21.1 oz/thrust 79.3% Efficient
GWS 8040 HD Hex 620 3S
10909 rpm @ 11.07v/9.59a 611 grams 21.5 oz/thrust 78.7% Efficient
GWS 8040 HD Tp 1320 3S
11077 rpm @ 11.3v/9.93a 631 grams 22.3 oz/thrust 78.1% Efficient

That first is the highest percentage efficiency I've recorded with one of these motors. I'm not "sold" on the idea that it's the neater layout, but it is possible (there are several mechanical factors to also take into mind, especially when the hardware tends to be -- shall we say -- a little variable).


Dave
Posted by timocharis | Dec 17, 2007 @ 06:22 PM | 10,389 Views
Good power, decent efficiency. Six turns 22awg. Runs well. But really I just love the way it looks. I almost never do a single layer ABC.
Posted by timocharis | Dec 16, 2007 @ 12:42 PM | 10,261 Views
I've tried a lot of setups to get the best power and efficiency I can out of a 5043 GWS HD prop running 2S under 10 amps. Goes easy on the TP 730 2s and/or Hex 620 2S batteries and works well with either a Phoenix 10 or Tbird 9. The motors go on combat wings where power is sort of nice, but not hyper critical. Light weight, control, durability and reliability are more important.

Still, why not do the best you can?

I've tried most of the small motors, and up to now the best was the Hex 16-gram wound 11 turns 24awg. But this motor tops it handily, by over five efficiency points. It's a 10-mag 8-turn 22awg Spike Wire monster. I won't be making any more because (a) it's a drag to seat the 10 magnets and (b) the 8 turns of 22awg is not easy.

But it's great fun to have done once. Here's the numbers:

Hex 8T 22awg dLRK 10-mag Wye Kv 19736/7.24 = 2725
GWS 5043 DD Hex 620 2S
16269 rpm @ 7.27v/9.65a 365 grams 12.9 oz/thrust 75.6% Efficient

Canna do 14T 24g delta captain (see below) but I might reprise it as a 14T 25awg delta just to see what happens. I do not look forward to setting the mags again, but that's life.
Posted by timocharis | Dec 15, 2007 @ 04:37 PM | 10,351 Views
After winding quite a few Hextronic 24-gram motors, my numbers started to indicate that a 14-turn 24-gauge dLRK Wye variant would probably be where the magic curves cross: the best combination of power and efficiency.

The problem was that 14 turns of 24awg wire just sticks up too much for the motor design. On some stators you can get the wire to fit, but the can rubs (or comes so close that just about any mishap will probably ruin the motor).

I thought about shimming the can forward, but just sort of backburnered the whole thing until ... one day ... the perfect stator/bearing tube combo arrived.

I savored it for weeks, then wound it up. Even let it sit for a day before soldering and testing. Here's what popped out:

Hex 14y 24g dLRK Raw Kv 1300 (15641/12.05) Io = 0.61 @ 12v
TP 730 3S 8040 *D:
9663 rpm @ 10.09v/7.05a 475 grams 16.8 oz/thrust 80.5% Efficient
Hex 620 3S 8040 *D:
10427rpm @ 11.23v/8.16a 557 grams 19.6 oz/thrust 79.2% Efficient

While it's true the 15-turn was able to hold 80.6% efficiency (and is the only other Hex 24-gram to break 80% it on my stand) it was at a significantly lower power level -- over 1.5 ounces less thrust. And to be just a hair under 80% efficiency at almost 20 oz of thrust is just too nice.

The 13-turn, done properly, produces a hair more thrust but gives up about four points in efficiency.

So the 14-turn 24awg is neither the most powerful nor the most efficient, but easily the best combination of both. Definitely the Hex 3S motor to beat.

Alas, there can be only one.

So far.


Dave
Posted by timocharis | Dec 13, 2007 @ 08:18 PM | 10,311 Views
Pete Johnson decided to get a candid shot of me dancing with my Tribute. I never did really like the plane, but I did like the way this shot turned out. Probably the best thing about it was the Microdan 2510. I wound it 13T 23awg for a 1060 GWS HD prop -- way over 80% efficiency and strong as a truck.

It lives on my Flash now. The Tribute was killed in a midair, which was something of a mercy. Crappy plane.


Dave
Posted by timocharis | Dec 13, 2007 @ 12:51 AM | 10,431 Views
My arm got a little twisted to do one of these, and it's a darn good thing. Just got the test results and this sucker broke records both 2S and 3S. Don't know what to make of it, but I'll have to do at least one more to see if it's repeatable.

Test results? Oh yeah, here they are:

Hex 15T 25awg Spike dLRK Wye Raw Kv = 1215 (9040/7.43):
GWS 8040 DD TP 730 3S
9250 rpm @ 10.22v/6.07a 434 grams 15.3 oz/thrust 80.6% Efficient
GWS 8040 DD Hex 620 2S
7497 rpm @ 7.77v/4.12a 281 grams 9.9 oz/thrust 81.2% Efficient
GWS 0843 RS Hex 460 2S
6844 rpm @ 7.56v/5.18a 353 grams 12.4 oz/thrust 70.5% Efficient

First repeatable break of the 80% barrier with a Blue Wonder (Badcock database for the 8040). The calculated thrust figures are slightly higher than observed, but the difference is tiny and my rig is probably variable. The 0843 results are about 0.1oz higher than observed, for example, and are taken from Drive Calculator rather than Badcock because their result was closer to the observation.

It's not a powerhouse, but it's extremely versatile and efficient. Gonna have to make another for meeeeee.


Dave