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Nov 29, 2007, 10:48 PM
GFBurke's Avatar

Whatt Meter testing.

Every test done with the Astro 101, Castle ESCs and CSRC lipos

SlowStick power setup test.
(this setup)
BP 08 motor, 3s lipo 1600mAH, 9x4.7 prop = 8.4A @ 91W WOT
(.1A generated from 2 LEDs)

JGF 450XT, 3s lipo, 10x4.7 prop = 13.2A @140W
JGF 450XT, 3s lipo, 9x4.7 prop = 8.4A @ 95W

Reno Racer power setup test
(this setup)
BP A2208-12 motor, 2s lipo 1250mAh, 8x4 E prop = 11.0A @ 75w WOT

Brushless FP belt power setup test
(.. ok scary test).
Arc110 motor, 3s lipo 800mAh, M24 blades = 5.7A @ 64W WOT
(.1A generated from 2 LEDs)

Pico Tiger Moth brushless power setup test
HXT 28-22-azj 7A 1400Kv motor, 8x3.8 prop, 2s lipo 800mAh = 6.0-6.3A @45W WOT

HyperFlea power setup test
Stock motor, stock prop, 2s lipo 1250mAh 10c= 12.0-12.4A @73W WOT
Stock motor, 6x4 Windsor black/square prop, 2s lipo 1250mAh 10c= 10.1A @67W WOT


Lynx power setup test
EDF x-Fan setup, 3s lipo 1500mAh 15c= 21A @220W WOT


SuperFly power test
this setup
- 3s lipo: 3s lipo 1500mAh 15c= 16.2A @160W WOT
- 2s lipo: 2s lipo 1250mAh 10c= 9.3A @62W WOT


36in FS RiteWing lightning
Arc 110 with 4.5x4.1 prop
- 3s lipo: 2200mAh 15c= 16A @160W WOT


Stryker power test
TowerPro 2409-12T motor
7x6E prop
Mystery 2200 15C 3s lipo
= 17.5A @170W WOT
(coke bottle cap method of mounting the TP 12T )
Last edited by GFBurke; May 25, 2008 at 01:41 PM.
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Nov 30, 2007, 12:24 AM
The "K"minator
Crazy Eight's Avatar
I see you got your whattmeter,sweeeeeet!
Nov 30, 2007, 12:38 AM
GFBurke's Avatar
Hehe.. ya.

The instructions say I can swap it in reverse and see how much I put back into the pack during charge.. I just need to figure out how to make/get some balance lead connectors to make an adapter..
(although with the calculations on draw, I can figure that out anyways.. I guess..)
Nov 30, 2007, 12:44 AM
The "K"minator
Crazy Eight's Avatar
Yea,you'll need a double male for one end,and a double female for the other.
It's nice to see what it actually takes to recharge.Calculations only work good with one throttle setting,not varying.
Nov 30, 2007, 12:54 AM
GFBurke's Avatar
Well this thing tells me how much in total I have pulled from the lipo during a session. It will tell me the amps per hour, watts per hour, and current state V of lipo. Here is the manual:
Your smarter on that stuff though.

Here is a pic of my adapters I made so far because I use Deans and mini Deans.
Nov 30, 2007, 12:10 PM
Registered User

Whatt meter

This is exactly what you need for propping data.
Nov 30, 2007, 12:14 PM
GFBurke's Avatar
I added mAh count. Now is that all the data needed to guestimate flight time assuming WOT all the time?
Last edited by GFBurke; Nov 30, 2007 at 12:46 PM.
Nov 30, 2007, 12:36 PM
The "K"minator
Crazy Eight's Avatar
Yep!But you don't use the total mah of the battery for the total mah you will use in flight.80% is about normal.
Nov 30, 2007, 12:39 PM
GFBurke's Avatar
Yep.. So.. what's the math involved again? It's early still.
Figure out %100 used, then reduce to 75-80% that should be used, then I can adjust figuring I wont be WOT constantly.

I'm sure the weight of the bird has some play too.. but I did these tests while holding them all down.
Nov 30, 2007, 12:48 PM
The "K"minator
Crazy Eight's Avatar
Here's a simple example; 800 mah pack at 100% usage,drawing 8amps = 6min.
this translates to; .8a divided by 8a =.1hours
Nov 30, 2007, 12:56 PM
Registered User

Prop data

This is what I found interesting from the link to the manual you provided.

"• Use it to choose the right prop to load your motor for best Amps.

Next install a propeller that is about 1 inch smaller then the recommended prop for the motor and throttle up slowly using the servo tester to command the speed control. Observe the current and do not exceed the manufacturer’s recommendation. If the amps are too high, pick a smaller prop and try again.

If you do not have a prop recommendation, start with a small prop and work you way up until you find a prop that loads the motor properly with the recommended battery. Remember larger props will draw more amps and smaller props will draw fewer amps. Higher battery voltage will draw more amps, lower voltage fewer amps. The Whattmeter will display the amps drawn, the battery voltage and the power delivered by the battery. If the Amps, Volts and Watts are close to the manufacturers data sheets and the RPM is ok then your motor is OK."

Now you can measure the load on the motor which affects the motors longevity. In another thread you talked about the increase in stability with higher headspeed. You also want headroom for bailing out of a potential crash. You also talked about doing tests on a variety of props.
Using this thing with each prop and your impression of its performance will help each of us make a choice. A prop with greater stability would be better for me as a learner as opposed to Chris with more experience. Data points on a spreadsheet would develope a lot of info for prop selection. Whack the ends off and reduce the diameter (reduce load) and see what happens. Cut the trailing edge down reduce DAR (reduce load) and see what happens, hell you could become Mr. Propellerhead (sorry about that, couldn't help myself.)
Do you remember where you got those bevel cut washers? Put one washer on top of the other and rotate one relative to the other and you change the pitch. Exciting stuff now that you can quantify what results.
Cool tool.
Last edited by hill0046; Nov 30, 2007 at 01:01 PM.
Nov 30, 2007, 01:36 PM
GFBurke's Avatar

I also have a digital scale so I could setup a motor/prop and a flat to get thrust in grams/oz.. hmm..
Nov 30, 2007, 01:36 PM
The "K"minator
Crazy Eight's Avatar
your SS setup would be 1.6 divided by 8.4=.19hours.x60=11.4 min
Nov 30, 2007, 01:39 PM
The "K"minator
Crazy Eight's Avatar
And then you'd know watts per gm/oz of thrust.
Nov 30, 2007, 04:24 PM
GFBurke's Avatar
Talking to a friend now. We will see about making an app for this.
What should this application figure? I know there is some online now, but we think we should do it.

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