[NSRCA-discussion] cost of electric

Fred Huber fhhuber at clearwire.com
Mon Sep 18 15:43:37 AKDT 2006 

its a "rule of thumb" similar to the "trade 1 inch pitch for 1 inch dia to 
keep the same load onthe engine" (which is pretty accurate at a 10X6 to 
11X5)

If propped correctly, you will hit 1 lb static thrust when drawing 100 watts

But if your goal is 3D performance... you might go to a longer, lower 
pitch... which could result in a measurable increase in "static thrust" 
without an increase in watt draw.  (electric gets wierd...) Maximum level 
flight airspeed would most likely suffer some though.

You could also change to smaller dia and more pitch... draw the same watts 
and get a bit less static thrust (but be able  to keep providing "+" thrust 
at higher airspeeds...

When the plane is going faster than the prop "wants to" pull the plane... 
you are providing "-" thrust (braking)) (something the glow seems to do 
better than the electric...)


----- Original Message ----- 
From: "Jack Keiser" <jtkeiser at comcast.net>
To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
Sent: Monday, September 18, 2006 10:24 AM
Subject: Re: [NSRCA-discussion] cost of electric


> Fred,
>
> Not yet into the electrics but I've been following this discussion trying 
> to
> learn and help decide if I want to make the plunge. Your comment about
> "100w/#  approx equals 1:1 power:weight" has me confused. Did you mean
> thrust-to-weight ?  Or??
>
> Jack
>
>
> ----- Original Message ----- 
> From: "Fred Huber" <fhhuber at clearwire.com>
> To: <nsrca-discussion at lists.nsrca.org>
> Sent: Monday, September 18, 2006 5:49 AM
> Subject: Re: [NSRCA-discussion] cost of electric
>
>
>> Watts per pound is a very good indicator of electric model preformance
>> regardless of size.
>>
>> 100 watts per pound is appx equal to 1:1 power:weight.
>>
>> Thus, we can be compareing "apples to apples" regardless of the size
>> difference.
>>
>> Intermediate.. I would "reprop" the Quest to appx 1000 watts. (the power
>> system is capable of it.. its just a bit harder on the batteries.)  I 
>> have
>> a
>> 13X6.5 on the motor, and its rated for a 14X8  (for appx 1200 watts) on
>> the
>> batteries I am using.
>>
>> I made the prop choice to get 15+ min per charge "sport" flying the 
>> model.
>> Its closer to 11 min doing the Pattern.  Repropping for more power.  My
>> reading indicates that if you want the LiPos to last, you want 15 min
>> capacity.
>>
>> **********
>>
>> And... the main reason I responded to the topic was...
>>
>>>>>>> Wow,  That is a bit out of my price range!
>>
>> Maybe the lesser performance of a system that is sized for a bit lower
>> power:weight would meet his needs...  Entry level  (Sportsman) Pattern
>> need
>> not cost a couple of thousand $$$$.  a common 4 ch basic radio and an ARF
>> similar to the Quest is a good plan... for that level. (a much better 
>> plan
>> than some other planes I tried...)
>>
>> Being able to get the WHOLE PACKAGE in the air electric powered, with the
>> charger and even including the RC system for appx $1000 may make a
>> difference.
>>
>> ********
>>
>> BTW.. there's a power package (motor, batt and ESC) which would have been
>> appropriate to the Quest, (or other .90 size, light, low cost Pattern/3D
>> ARF's)  For Sportsman level (rated for 900 watts max on the motor and 
>> ESC)
>> which costs $150 less than the power packge I set up.  But.. You can't
>> re-prop it up for Intermediate...
>>
>> ----- Original Message ----- 
>> From: "Scott Anderson" <scott at rcfoamy.com>
>> To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
>> Sent: Sunday, September 17, 2006 8:47 PM
>> Subject: Re: [NSRCA-discussion] cost of electric
>>
>>
>>>I believe the Quest is a small plane (Specifications:)
>>> Wingspan: 68.5"
>>> Wing Area: 1000 sq. in.
>>> Ready-to-fly weight: 7.5 - 8.5 lbs.
>>> Length: 69"
>>>
>>> We are not doing a even comparison to a 2 meter plane..
>>>
>>> I fly intermediate and will be moving to advanced next year and its 
>>> still
>>> nice to have extra power...
>>>
>>>
>>> Scott Anderson
>>>
>>>
>>>
>>> ----- Original Message ----- 
>>> From: "paul.horan" <paul.horan at sbcglobal.net>
>>> To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
>>> Sent: Sunday, September 17, 2006 9:35 PM
>>> Subject: Re: [NSRCA-discussion] cost of electric
>>>
>>>
>>>> Scott,
>>>>    I have seen Fred's Quest fly - it is electric and it is more than
>>>> sufficient for sportsman and the beginning of intermediate.
>>>>    I believe he is correct in his statement.
>>>> Thanks,
>>>> Paul
>>>>
>>>> ----- Original Message ----- 
>>>> From: "Scott Anderson" <scott at rcfoamy.com>
>>>> To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
>>>> Sent: Sunday, September 17, 2006 8:17 PM
>>>> Subject: Re: [NSRCA-discussion] cost of electric
>>>>
>>>>
>>>>> Fred,
>>>>>
>>>>> 100 watts per pound is marginal for pattern..
>>>>>
>>>>> And I don"t fly Masters !
>>>>>
>>>>> Just my 2 cents..
>>>>>
>>>>> Scott Anderson
>>>>> Team Tanicpacks.com
>>>>> Team Castle Creations
>>>>>
>>>>>
>>>>> ----- Original Message ----- 
>>>>> From: "Fred Huber" <fhhuber at clearwire.com>
>>>>> To: <nsrca-discussion at lists.nsrca.org>
>>>>> Sent: Sunday, September 17, 2006 9:12 PM
>>>>> Subject: Re: [NSRCA-discussion] cost of electric
>>>>>
>>>>>
>>>>>> The costs they listed are for a plane competitive at Masters or 
>>>>>> above.
>>>>>> Sportsman simply doesn't require the same performance from the model.
>>>>>> (each
>>>>>> successive level demands more from the plane and pilot)
>>>>>>
>>>>>> Sportsman (flying the schedule used the past couple of years) level
>>>>>> needs
>>>>>> appx 100 watts/ lb and you can get a decent e-power plane set up for
>>>>>> close
>>>>>> to half the cost. (probably less, as prices are comming down)
>>>>>>
>>>>>> It depends on the performance level you want or need.  I believe the
>>>>>> setup
>>>>>> Nat recommends approaches 200 or 250 watts/lb in an 11 lb plane...
>>>>>> Desireable for the HUGE verticals with rolls on up lines at Masters
>>>>>> and
>>>>>> FAI
>>>>>> level.
>>>>>>
>>>>>> *************
>>>>>>
>>>>>> BEST is to charge the LiPos at no faster than 1C rate... so it takes 
>>>>>> 1
>>>>>> hr
>>>>>> for a fully depleted pack.
>>>>>>
>>>>>> don't forget to get a cell ballancer, and a Wattmeter.  Adds appx $75
>>>>>> to
>>>>>> the
>>>>>> bill. ($25 for Astro Blinkey... and $50 for the wattmeter).. but the
>>>>>> ballancer increases the life of the LiPos, (and makes charging safer)
>>>>>> and
>>>>>> the wattmeter allows you to test the power draw with assorted props,
>>>>>> to
>>>>>> ensure you aren't overloading something.
>>>>>>
>>>>>> ----- Original Message ----- 
>>>>>> From: "Kelly Regan" <kelly.regan2 at verizon.net>
>>>>>> To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
>>>>>> Sent: Sunday, September 17, 2006 7:44 PM
>>>>>> Subject: Re: [NSRCA-discussion] cost of electric
>>>>>>
>>>>>>
>>>>>>> Wow,  That is a bit out of my price range!
>>>>>>> My Brio on gas idea is looking better!  ;)
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Nat Penton wrote:
>>>>>>>> Kelly
>>>>>>>> My experience (from memory):
>>>>>>>>
>>>>>>>> Plett EVO and ESC                 About   $800
>>>>>>>> TP 5300 5S 4P                       Check Website
>>>>>>>> 2 - Astro 109 chargers                           280
>>>>>>>> 12v Iota power supply                              90
>>>>>>>>
>>>>>>>> If you use 75% capacity it will take 35 to 45 minutes to charge the
>>>>>>>> batteries. 2C charging will not hurt the batteries but you cannot
>>>>>>>> get
>>>>>>>> more
>>>>>>>> than 8amps out of the Astros. I still like the Astros and, when in
>>>>>>>> the
>>>>>>>> shop,
>>>>>>>> charge the batteries in parallel. Balancing is no problem.
>>>>>>>>
>>>>>>>> The Iota is a great piece of equipmment and will easily handle four
>>>>>>>> Astro
>>>>>>>> 109s.                        Nat
>>>>>>>>
>>>>>>>> ----- Original Message ----- 
>>>>>>>> From: "Kelly Regan" <kelly.regan2 at verizon.net>
>>>>>>>> To: <NSRCA-discussion at lists.nsrca.org>
>>>>>>>> Sent: Saturday, September 16, 2006 5:40 PM
>>>>>>>> Subject: [NSRCA-discussion] cost of electric
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>> Can someone post the cost of a 2 meter electric setup.
>>>>>>>>>
>>>>>>>>> Motor
>>>>>>>>>
>>>>>>>>> Speed Control
>>>>>>>>>
>>>>>>>>> Battery size and cost
>>>>>>>>>
>>>>>>>>> Also how long does it take to charge one battery pack at a
>>>>>>>>> reasonable rate, something that won't kill the battery life.
>>>>>>>>>
>>>>>>>>> Thank you for the help.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> -- 
>>>>>>>>> Kelly Regan
>>>>>>>>> Visit the Georgetown Branch: http://mysite.verizon.net/vze6uror/
>>>>>>>>> Freestate Aeromodelers: http://www.freestateaeromodelers.org/
>>>>>>>>>
>>>>>>>>> _______________________________________________
>>>>>>>>> NSRCA-discussion mailing list
>>>>>>>>> NSRCA-discussion at lists.nsrca.org
>>>>>>>>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> -- 
>>>>>>>>> Internal Virus Database is out-of-date.
>>>>>>>>> Checked by AVG Free Edition.
>>>>>>>>> Version: 7.1.405 / Virus Database: 268.11.7/437 - Release Date:
>>>>>>>>> 9/4/2006
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>> -- 
>>>>>>> Kelly Regan
>>>>>>> Visit the Georgetown Branch: http://mysite.verizon.net/vze6uror/
>>>>>>> Freestate Aeromodelers: http://www.freestateaeromodelers.org/
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> NSRCA-discussion mailing list
>>>>>>> NSRCA-discussion at lists.nsrca.org
>>>>>>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>>>>>>>
>>>>>>>
>>>>>>>
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>>>>>>
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