[NSRCA-discussion] 12S for F3A

Mon Nov 14 17:11:56 AKST 2016

Watts in the air?  On the ground?  At what temperature?  Beginning of flight?  After flight?  How do you apply the same limit to glow/IC?

We have a hard enough time now checking sound and weight.  

Regards,

Dave

From: cahochhalter [mailto:cahochhalter at yahoo.com] 
Sent: Monday, November 14, 2016 9:06 PM
To: Dave Lockhart <davel322 at comcast.net>; General pattern discussion <nsrca-discussion at lists.nsrca.org>
Subject: Re: [NSRCA-discussion] 12S for F3A

Maybe if we promise.

What if we limit watts? But 12s.

Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: Dave Lockhart via NSRCA-discussion <nsrca-discussion at lists.nsrca.org <mailto:nsrca-discussion at lists.nsrca.org> > 
Date: 11/14/16 7:20 PM (GMT-06:00) 
To: 'General pattern discussion' <nsrca-discussion at lists.nsrca.org <mailto:nsrca-discussion at lists.nsrca.org> > 
Subject: Re: [NSRCA-discussion] 12S for F3A 

Below is a partial snip of a thread earlier this year on the F3A discussion list.

The long and the short of it is that going from 10S to 12S might help in the short term, but, will be yet another round of escalation in the long term.

Regards,

Dave

From: F3A-Discussion [mailto:f3a-discussion-bounces at lists.f3a.us] On Behalf Of Dave Lockhart via F3A-Discussion
Sent: Thursday, September 01, 2016 8:20 PM
To: 'Atwood, Mark' <atwoodm at paragon-inc.com <mailto:atwoodm at paragon-inc.com> >; f3a-discussion at lists.f3a.us <mailto:f3a-discussion at lists.f3a.us> 
Subject: Re: [F3A-Discussion] Rule proposals

I’ve been flying pattern since the early 1980s….and have come to be fond of a couple answers to one question –

Q – How much power is enough?

A – Way too much.

A – More.

A – I’ll let you know when I find it.

In the last 30 years of pattern history, the power used has always been the most available.  Zero exceptions.

The history of power limits as it were –

Max engine size – 60 cubic in – everyone ran 60s with pipes (and many pushed high nitro low oil fuels for more power).

Max engines size – 60 2C or 120 4C.  This was to allow more diversity, lower noise, “friendlier” power, etc.  Didn’t happen – everyone ended up running more expensive 120 4Cs (and many pushed high nitro for more power).  

Unlimited engine size - Again, to allow more diversity, lower stressed powerplants, cheaper cost, etc.  Didn’t happen (again)  – everyone ran a limited number of purpose built more expensive 2C and engines (and many pushed high nitro for more power).

Specific YS evolution – 120, 120AC, 120SC, 140, 140L, 140DZ, 160, 175, 185…….and running 30% nitro the entire history.

Specific Electric evolution – (really the batteries) – ThunderPower 10s4p8000 4-6C, TP10s4p5300 10-12C, TP10s2p5400 18-20C, then several generations of 25C up to the current ProLite X (and similar offerings from other brands).  The promise of every successive generation was more power, lower operating temps, and longer lifecycles.  In just about every instance, more power was realized (and used)….and operating temps and lifecycles were not dramatically changed (since about generation 4 of about 8 generations).

Any time the opportunity to escalate power (and costs) was available, it happened.

All of Mark’s points are valid IF the power level remains CONSTANT.  IF the power level INCREASES (and it will), the advantages Mark notes will not be realized…..but the detriments will be – increased cost to change motors, chargers, and lipos, and a reduced secondary market to which the 10S setups can be “recycled”.

The nature of competition is to push the envelope and exploit any possible competitive advantage.  12S will be a competitive advantage, and the power level will go up.  I see no reason why the historical trend of pattern and/or competitive nature will change.  Given a suitable transition period, the power systems will all be 12S, and just as stressed as they are now with 10S. 

Regards,

Dave

From: Atwood, Mark [mailto:atwoodm at paragon-inc.com] 
Sent: Thursday, September 01, 2016 2:44 PM
To: DaveL322 <DaveL322 at comcast.net <mailto:DaveL322 at comcast.net> >; f3a-discussion at lists.f3a.us <mailto:f3a-discussion at lists.f3a.us> 
Cc: Derek Koopowitz <derekkoopowitz at gmail.com <mailto:derekkoopowitz at gmail.com> >; Ramsey Don <donramsey at gmail.com <mailto:donramsey at gmail.com> >
Subject: Re: [F3A-Discussion] Rule proposals

So to chime in here… 

Yes, Amps kill… but the body has natural impedance that requires sufficient voltage to push through it.  Right now if you accidentally short a 10S pack, (and I’m guessing many of us have) we don’t feel the jolt even though over 200amps have likely passed, but rather we typically just get burned on the skin (and melt a connector).  This is because the resistance in your skin prevents the amperage from traveling through you.  50V won’t meaningfully impact that.  Yes, it’s an increase, but not a dangerous one.   It’s pretty universally accepted that 50v DC is safe at any amperage (from it being lethal) up to and including putting electrodes under the skin.  Not something I’d advise trying.

There are a number of strong upsides to this. We currently run our equipment very hard, and very hot.  Up-ing the voltage by 20% would significantly reduce both and significantly increase the efficiency and tolerance of the systems in play.   Weight would not be impacted as you would run lower capacity, higher voltage cells that would weigh roughly the same, but run cooler, last longer, and provide equal or longer flight times.

The clear downside as mentioned would be a bit of retooling for those that want to change.   Motor’s have to be wound differently, so a 12S Pletty is different from a 10S Pletty, though it’s the same motor casing and such, so it would be plug n play in the airframes.     

Batteries we buy pretty steadily just like we did fuel… so I would imagine most would simply replace motors when they put together new airplanes and phase in new batteries as a result.  Charges would indeed be a brand new expense if you don’t currently have a charger that can handle 12S (many do as F3C and many others already run 12S.)

Overall I would be interested in this simply due to the current excessive wear on our equipment from the high amperage loads and heat.  Running 55amps vs 70amps reduces the strain on everything all the way down to the gauge of wire we run.

MARK ATWOOD

o.  (440) 229-2502

c.  (216) 316-2489

e.   <mailto:atwoodm at paragon-inc.com> atwoodm at paragon-inc.com

Paragon Consulting, Inc.

5900 Landerbrook Drive, Suite 205, Cleveland Ohio, 44124

 <http://www.paragon-inc.com/> www.paragon-inc.com

Powering The Digital Experience

From: DaveL322 [mailto:DaveL322 at comcast.net] 
Sent: Friday, November 11, 2016 1:25 PM
To: S. McNickle <nelson_jett at comcast.net <mailto:nelson_jett at comcast.net> >; General pattern discussion <nsrca-discussion at lists.nsrca.org <mailto:nsrca-discussion at lists.nsrca.org> >; Larry Diamond <ldiamond at diamondrc.com <mailto:ldiamond at diamondrc.com> >
Cc: Hansen, Ron <rcpilot at wowway.com <mailto:rcpilot at wowway.com> >
Subject: Re: [NSRCA-discussion] 12S for F3A

100% correct.

I previously made a lengthy post to the F3A mailing list and will repost to this list when I am home after the weekend (f3p contest).

Regards,

Dave

Sent from my Sprint Samsung Galaxy Note5.

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