[F3A-Discussion] Rule proposals

Dave Lockhart davel322 at comcast.net
Thu Sep 1 16:22:15 AKDT 2016


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>; f3a-discussion at lists.f3a.us
Cc: Derek Koopowitz <derekkoopowitz at gmail.com>; Ramsey Don <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

 

On Sep 1, 2016, at 1:47 PM, DaveL322 via F3A-Discussion <f3a-discussion at lists.f3a.us <mailto:f3a-discussion at lists.f3a.us> > wrote:

 

Yes.  Volts don't kill.  Amps do.

 

The potential for high amperage rates increases as voltage increases.  I don't recall the specifics, but the amount of amps generally transmittable at 42v is significantly less likely to cause (human) harm than 50v....and that is where the 42v limit originally came from.

 

I understand the technical benefits of using higher voltage power systems.  That said, if we are going to obsolete 10s lipos, motors, and chargers.....and accept the increased health risk of 50v.....why stop at 12s?  All the benefits of 12s (vs10s) would be further realized by going to 14s or 16s.

 

1, 3, 4, 5......all good.

 

Regards,

 

Dave

 

Sent from my Sprint Samsung Galaxy Note5.

 

-------- Original message --------

From: Derek Koopowitz via F3A-Discussion <f3a-discussion at lists.f3a.us <mailto:f3a-discussion at lists.f3a.us> > 

Date: 9/1/16 1:19 PM (GMT-05:00) 

To: Don Ramsey <donramsey at gmail.com <mailto:donramsey at gmail.com> > 

Cc: f3a-discussion at lists.f3a.us <mailto:f3a-discussion at lists.f3a.us>  

Subject: Re: [F3A-Discussion] Rule proposals 

 

Thanks Don! 

 

BTW, if anyone has some additional thoughts on why going to 12 cells isn't going to harm someone (voltage wise), please let me know.  I had heard (old wives tale perhaps) that moving above 50v of direct current increases the risk of death - actually I believe it is more the number of milliamps (current) that is lethal versus the voltage.

 

On Thu, Sep 1, 2016 at 10:08 AM, Don Ramsey <donramsey at gmail.com <mailto:donramsey at gmail.com> > wrote:

Nice job Derek.  I would hope all are approved.

 

Don

 

From: F3A-Discussion [mailto:f3a-discussion-bounces at lists.f3a.us <mailto:f3a-discussion-bounces at lists.f3a.us> ] On Behalf Of Derek Koopowitz via F3A-Discussion
Sent: Thursday, September 1, 2016 11:17 AM
To: f3a-discussion at lists.f3a.us <mailto:f3a-discussion at lists.f3a.us> 
Subject: [F3A-Discussion] Rule proposals

 

Hi everyone,

 

I've created 5 rule proposals that I will be submitting to CIAM to be considered for our next rules cycle.

 

1.  Rule clarification on rolls in the same direction

2.  Modify electric to use 12 cells instead of 10

3.  Change the number of judges from 20 to 16

4.  Allow a junior WC to fly in the next WC as a defending WC provided they are still a junior

5.  Clarify the definition of a pilot/caller as a team

 

See the attached.

 

Let me know your thoughts ASAP so that I can get these submitted.  BTW, if you'd like to see other rule changes, let me know and I can work on getting it submitted, if it makes sense.

 

-Derek

 

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