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Old Apr 12, 2012, 09:36 PM
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United States, MI, Grand Blanc
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Originally Posted by Alpha_Geist View Post
Egads! Pappabatman in the PZ warbirds forum recommended that motor for a speed demon setup. I think he installed it in his Corsair and was clocked at like 111mph. Speed kills...lol
That's nothing lol. You should have seen it with the Hyperion Zs3026-1400. To be honest, which I try to be, the t28 reaches a point were its just not going to go any faster. I did put the 3026 in a pzp51 and collapsed the wings. It was great fun while it lasted. Should have glassed it. I even ran the 3026 on 6s once but, after reading the watt meter I decided 130a was a bit much for the mystery 100a ESC. It didn't cook the ESC though. Go figure.

What's great with the 3014 and 3020 is I can put around at 1/4 stick or lower for about 14 min (did that today) and my packs were at 11.34v. Of course most of the time I was climbing for short (but huge vertical) bursts and the floating around doing loops rolls and the like. Insanely fun.

Let's say some idiot was into punishing motors and let's say that idiot used cheap parkzone warbirds to do it in, what OS motor would you guys recommend? I have a ton of 42"ish planes.

Im leaning towards that 1200kv motor since it fits my WAY over 100w/lbs style.

Also what ESC are you guys having luck with? Im building. WWI bipe that may get one of these (not the 1200kv) if all goes well.
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Old Apr 12, 2012, 09:38 PM
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United States, MI, Grand Blanc
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Quote:
Originally Posted by Ron van Sommeren View Post
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 power by a factor two.

Vriendelijke groeten Ron
diy motor tips Drive Calculator
diy motor group Cumulus MFC
Get a life ... get a Watt-meter!!!
Couldn't have said it better.
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Old Apr 12, 2012, 10:04 PM
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United States, WI, Chetek
Joined Jul 2011
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Quote:
Originally Posted by Ron van Sommeren View Post

Nice O.S. thread, for your daily fix of paranoia:
http://www.rcgroups.com/forums/showthread.php?t=1611380

I think it's time I told you guys what contrails really are about
I don't need any paranoia.

I really hope your kidding about the contrails....because if you are not...you are whacked. Im one of those guys that makes those "scary" contrails. If you are joking...fine....carry on.
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Old Apr 12, 2012, 10:12 PM
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United States, MI, Grand Blanc
Joined Mar 2012
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Originally Posted by JurassicJet View Post
I don't need any paranoia.

I really hope your kidding about the contrails....because if you are not...you are whacked. Im one of those guys that makes those "scary" contrails. If you are joking...fine....carry on.
Im 100% positive he is joking.

The thread he referenced is hilarious, except some may believe the guy actually knows what's he's talking about.
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Old Apr 13, 2012, 12:34 AM
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United States, CA, Elk Grove
Joined Dec 2011
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Quote:
Originally Posted by lostinthesun View Post
That's nothing lol. You should have seen it with the Hyperion Zs3026-1400. To be honest, which I try to be, the t28 reaches a point were its just not going to go any faster. I did put the 3026 in a pzp51 and collapsed the wings. It was great fun while it lasted. Should have glassed it. I even ran the 3026 on 6s once but, after reading the watt meter I decided 130a was a bit much for the mystery 100a ESC. It didn't cook the ESC though. Go figure.

What's great with the 3014 and 3020 is I can put around at 1/4 stick or lower for about 14 min (did that today) and my packs were at 11.34v. Of course most of the time I was climbing for short (but huge vertical) bursts and the floating around doing loops rolls and the like. Insanely fun.

Let's say some idiot was into punishing motors and let's say that idiot used cheap parkzone warbirds to do it in, what OS motor would you guys recommend? I have a ton of 42"ish planes.

Im leaning towards that 1200kv motor since it fits my WAY over 100w/lbs style.

Also what ESC are you guys having luck with? Im building. WWI bipe that may get one of these (not the 1200kv) if all goes well.
You can do what I did and put the 1200kV in the PZ P-51 and the PZ F4F Wildcat. Go 4S with an 8x8 or 9x6.
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Old Apr 13, 2012, 02:58 AM
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United States, CA, Elk Grove
Joined Dec 2011
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Alright Ken,

I'm back home and I've looked through the 3820-1200 4S 9x6e data from my ICE Logs and wattmeter. Tests were done static in the P-51 airframe at WOT for at least 15 second sessions each. I took a break from testing after 2 consecutive 4S lipos in order to cool the motor down and prevent the magic smoke from releasing. Tests were done on the only 4S lipos that I own, so only 5 tests performed after a fresh charge of the battery.

Test #1 w/ Hyperion 4S 2100mAh 25C
ICE Log: 52.1A max & 745W max
Wattmeter: 53.28A max & 766W max

Test #2 w/ Hyperion 4S 2200mAh 35C
ICE Log: 53.8A max & 785W max
Wattmeter: 54.57A max & 795.7W max

Test #3 w/ Hyperion 4S 2600mAh 35C
ICE Log: 53.8A max & 777W max
Wattmeter: 54.02A max & 788.4W max

Test #4 w/ Turnigy Nano-Tech 4S 2650mAh 35C
ICE Log: 52.1A max & 745W max
Wattmeter: No data

Test #5 w/Turnigy Nano-Tech 4S 2250mAh 65C
ICE Log: 54.6A max & 789W max
Wattmeter: 56.93A max & 847.8W max

As you can see from comparing data from both ICE log and the wattmeter, there are slight variations in recorded current and power. Despite the variation, the data isn't very far off from each other. Plus, the max current never reached 60A, although it got pretty damn close. Considering the current was under the 75A max of the motor's limits, I think the setup is airworthy as long as there is ample cooling.

What I haven't tested yet is the flight times for such setup. I will know this Sunday when we get a break in the rainy weather we are having. I don't fly at WOT 100% of the time, just on some verticals and low level passes. I'll be happy if I can get some 5 minute flights on 4S. The nice thing is after I've used up my 4S packs, I can pop in some 3S packs in and enjoy a nice +7 minute cruises.

NOTE: Check out the RPM's for the Hyperion 2200 35C test. ICE recorded 104701 RPM's. How accurate this is, I can't say. What I can say is that prop might double as a secondary food processor.
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Old Apr 13, 2012, 07:01 AM
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United States, WI, Chetek
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Quote:
Originally Posted by lostinthesun View Post
Im 100% positive he is joking.

The thread he referenced is hilarious, except some may believe the guy actually knows what's he's talking about.
Whew. I was hoping so.
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Old Apr 13, 2012, 07:21 AM
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Ken Myers's Avatar
Commerce Township, MI
Joined Aug 2001
4,519 Posts
Alpha_Geist,

Looks like you forgot to set the poles for data logging on the ICE ESC to 14. That is why you got such an unusual RPM of 104,701.

The photos of your power meter shows that the captured numbers do not compute exactly.
Example: TURNIGY NANO-TECH 2250 65C 56.93A * 14.923V = 849.6W or looking at it another way 847.8W / 56.93A = 14.892v
That's not a huge problem at all, but I just wanted to note it.

Your motor closely matches my #2 motor. Drive Calculator results using 14.923V and the APC 9x6E prop:
56.1A, 837.4 watts in, 15,092 RPM, pitch speed 85.75 mph
Your readings show:
56.93A max & 847.8W max for the same voltage

If you look back at post #183 you'll see:
“Expected power meter readings for decent 4S pack and APC 9x6E
Near top of charge: 15.6v, 60 amps, 936 watts in, 15,550 RPM, pitch speed 88.4 mph
Reading after initial "run off": 14.8v, 55 amps, 814 watts in, 14,950 RPM, pitch speed 85 mph
Not such a good Li-Poly: 14v, 50 amps, 700 watts in, 14,350 RPM, pitch speed 81.5 mph”

Your readings were very close to Drive Calculator's prediction when I'd set the voltage to 14.8v, as I noted “after initial 'run off'”.

I combined the data from my two motors to create an “average motor” for Drive Calculator. Using that version with the 9x6E prop and voltage set at 14.923 yields the following:
55.8A, 832.7 watts in, 15,075 RPM, pitch speed 85.6 mph

Once again, close enough to be a good prediction tool. That why I like Drive Calculator so much. With accurate input, its predictions are very good.

Thanks for verifying my collected data.

Ken
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Old Apr 13, 2012, 07:42 AM
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Australia, ACT, Kambah
Joined Feb 2001
3,266 Posts
Ken,
from your measured data does DriveCalc allow you to estimate a Kv for the 3820-1200? The reason I ask is that the using the published Kv=1200 in ecalc seems to consistently underestimate the actual current I am seeing. Clearly your average motor in Drivecalc aligns much better with real world - but I'm not familiar with Drivecalc so I don't know it it's using a manually entered Kv or deriving it somehow. I guess now I've got better data sources it's time to learn to use DC

I've now got the emeter rpm sensor plugged into my motor so I should be able to get some 4S 8x6 and 8x8 readings soon

Thanks

Scirocco
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Old Apr 13, 2012, 08:40 AM
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Ken Myers's Avatar
Commerce Township, MI
Joined Aug 2001
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Drive Calculator does indeed calculate the Kv. I've attached an image of where to find it. It is NOT on the main page. The number noted as ns xxxx rpm/V on the main page is not the number to look at. It is on the Motor info window.

You'll note that DC calculates the Kv at 1245.9

I used the drill press method to calculate the Kv on both motors:
For my composite motor, data based on both motors is calculated to 1245.6
Motor #1 1242
Motor #2 1249

A conclusion that I reach in my review is that the Kv is about 1245 NOT 1200.

All of my data will be online soon, with my review, but I'm off to Toledo now for the Weak Signals RC Expo.
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Old Apr 13, 2012, 10:31 AM
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United States, CA, Elk Grove
Joined Dec 2011
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Quote:
Originally Posted by Ken Myers View Post
Alpha_Geist,

Looks like you forgot to set the poles for data logging on the ICE ESC to 14. That is why you got such an unusual RPM of 104,701.

The photos of your power meter shows that the captured numbers do not compute exactly.
Example: TURNIGY NANO-TECH 2250 65C 56.93A * 14.923V = 849.6W or looking at it another way 847.8W / 56.93A = 14.892v
That's not a huge problem at all, but I just wanted to note it.

Your motor closely matches my #2 motor. Drive Calculator results using 14.923V and the APC 9x6E prop:
56.1A, 837.4 watts in, 15,092 RPM, pitch speed 85.75 mph
Your readings show:
56.93A max & 847.8W max for the same voltage

If you look back at post #183 you'll see:
“Expected power meter readings for decent 4S pack and APC 9x6E
Near top of charge: 15.6v, 60 amps, 936 watts in, 15,550 RPM, pitch speed 88.4 mph
Reading after initial "run off": 14.8v, 55 amps, 814 watts in, 14,950 RPM, pitch speed 85 mph
Not such a good Li-Poly: 14v, 50 amps, 700 watts in, 14,350 RPM, pitch speed 81.5 mph”

Your readings were very close to Drive Calculator's prediction when I'd set the voltage to 14.8v, as I noted “after initial 'run off'”.

I combined the data from my two motors to create an “average motor” for Drive Calculator. Using that version with the 9x6E prop and voltage set at 14.923 yields the following:
55.8A, 832.7 watts in, 15,075 RPM, pitch speed 85.6 mph

Once again, close enough to be a good prediction tool. That why I like Drive Calculator so much. With accurate input, its predictions are very good.

Thanks for verifying my collected data.

Ken
Ah! Thanks for pointing out about about the RPM and pole count settings. I completely forgot about changing the kV and pole count in the data log. Yeah, 104k rpms made me scratch my head when I saw it too.

I'm not sure why the wattmeter values (P=IV) didn't exactly match. Maybe because of a variable rate of change of voltage when given the first burst if throttle? Even the ICE logs report slightly different values too, but are only off by 3-5 watts. Then again, voltage is given in tenths as opposed to hundred thousandths compared to the watt meter.

I'm downloading DriveCalc right now. Hope to play with it later this afternoon. Have fun at the Expo!
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Old Apr 13, 2012, 03:32 PM
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Commerce Township, MI
Joined Aug 2001
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I haven't uploaded the .25 yet. I'll do it right now. It takes Christian Persson a few days to get the program updates out, so maybe look for it in a week.
The O.S. 32 is in there now though. I put it in last fall some time.

Just walked in the house from coming back from Toledo, OH at the RC Expo. Nothing too great there and only picked up a Sanyo Eneloop receiver pack for my new project.

I just did a screen capture of the data for this motor. You can just add a new motor to Drive Calculate (see the help file) and copy in the data from this screen capture, that way you can "play" with it before the update gets out.
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Old Apr 14, 2012, 01:59 PM
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Ken Myers's Avatar
Commerce Township, MI
Joined Aug 2001
4,519 Posts
Review Ready

I just finished up and posted my review of the OMA-3020-1200 at

http://www.theampeer.org/OMA-3820-12...-3820-1200.htm

As always, comments are welcome.

Ken Myers
The Ampeer: http://www.theampeer.org
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Old Apr 14, 2012, 02:10 PM
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Gary, IN, USA
Joined Jul 1999
994 Posts
I was at the Toledo Show on Friday and couldn't find the O.S. motor anywhere on the main floor. There was a booth but they only had the wet engines. Saw nothing really new in electric power at any vendor. Lots of Hacker motors in various booths. Where ever I looked, there were higher prices. Same number of occupied vendor booths as last year. I think I found a LHS that has the motor to check out.
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Old Apr 14, 2012, 02:41 PM
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Commerce Township, MI
Joined Aug 2001
4,519 Posts
Jim,

Be sure to go over the review before purchasing the OMA-3020-1200. It may or may not be what you are after, and is really designed to a single purpose using Li-Poly batteries.

It works out wonderfully for me using a 3S "A123" 2300mAh pack and Master Airscrew 10x8 G/F 3 series prop. Just what I was looking for.

Personally, I was totally underwhelmed with Toledo this year, but that is just me, old, jaded and crotchety.
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