Author Topic: Rules for Electric in Size limit events? (Read 930 times)

Rudy Taube · « **on:** June 19, 2007, 12:54:46 AM »

More "Rules" .... Fun Fun Fun!

This is an issue that was touched on by Dick, and Pat in the Elec. 1/2 A subject. I wanted to make a new subject so as not to hijack the 1/2A thread.

In CL PA we only have two size limit events that I know of, P-40 and 1/2A. It looks like the P-40 problem will resolve itself in a year or two because of the movement toward removing the power size limit in this event nationwide. We are moving in that direction here in the SW, and it looks like this will be the new rule for 2008 contests in SoCal. But for now many CDs still enforce the .40 size.

I just encountered such a CD in Northern California. I wanted to sign up my electric P-40 in their P-40 event at their August contest in Woodland. The CD was very nice, but said NO, electrics were allowed in his P-40 event, but welcome in CLPA.

We had a pleasent exchange of emails. His main reason for his "NO" ans. was a good one:
"..... as a CD I have no way of knowing what electric motor/battery combination is equivalent to a IC .40". He went on to suggest that we (elec. flyers) should get the CL contest board, and or the AMA to give CDs a written guideline on Elec. motor size to IC engine size. I agreed that he has a very good point.

I would appreciate any input from our elec. group and rules experts. ..... Keith? Dean? or?

We do have a rule that may help us with this P-40 issue. The CLPA rules are .91 limit for IC engines and 42 Volts for elec. systems. If we just stay with the VOLTS as the size limit this means that a .40 IC = an elec motor powered by 18.46 VOLTS. This means our standard AXI/13V to 15V system should be allowed in a .40 IC size limit event. ... What do you guys think??

Fortunately, here in SoCal I have entered three different contests with three different CDs and they all have accepted my contension that my setup (using approx. 70% power) is = to a .40 size IC engine. I showed them that it turned the exact same prop at the same RPM and the same lap times as my Aero Tiger .36, and it flew like the other .40 size planes .... (well my plane flew like the other planes, but sadly, the maneuvers reflected the poor flying skills of the pilot. ;-)

Unfortunately the above VOLTS % formula does not seem to be uniform throughout the entire spectrum. I came out with 2.25 Volts for a 1/2A when using a simple % of .91 VS 42 Volts ratio. This would not fly a 1/2A plane, but the .40 to 18.46V sounds about right (actually elec. @ 18V may be about = to a good Randy Smith .40 IC ? This would still be legal in P-40)

Any input would be greatly appreciated. We have several more contests here in CA this year, and I, and maybe some others would like to fly elec. in P-40, and spread the word on ECL. And we would like to have something in writting to help CDs with their decisions on electric planes in their contests.

I will leave combat, carrier, speed, etc. to others.

Regards,

Kim Doherty · « **Reply #1 on:** June 19, 2007, 02:55:42 PM »

Rudy,

I am sure that you realize that there is no one on the face of this earth that supports your right to fly electric model planes that conform to the rules of a particular event more than I do. I think you have actually gone a long way to answering your own question when you acknowledged that the P40 issue would take care of itself in the next couple of years. (through a rules change) While I think everyone involved would welcome your participation in the event, I am equally sure that you would be (or could be) competing with an unfair advantage not addressed in the current event rules. If you are really serious about flying in the current P40 event, perhaps you could build a plane that met the rules as they are now written. I realize that you can try to convince a CD to let you do just about anything but that is not IMHO in keeping with the spirit of the rules or good sportsmanship.

When I decided to enter an electric plane at the W/C's last summer, I did so with the full blessing of the rules. When the stunt rules in my own country did not support electric flight I took the steps necessary to make the required changes. In short, I support the existing rules for any event in their entirety.

On the subject of equivalents in the electric world to cubic inch displacement categories, I do not believe that they can exist in any easily measurable or enforceable manner such that they (electric powertrains) can be utilized in a fixed or limited displacement event without making a rules change. There is no question in my mind that they would have a potentially unfair advantage.

Your assumption that 42 volts is the linear equivalent to 0.0 cubic inches to .91 cubic inches of displacement is not correct. My powertrain setup with Orbit 30-12 and Thunderpower 5S2P 4200 battery is pretty much the equivalent of a .91 cubic inch setup (should I desire to work it that hard) yet it puts out only 18.5 volts! (5 cells X 3.7v/cell) The problem with trying to determine an electric equivalent based on voltage is that it is only one of two very important inputs to the power equation.

I am positively giddy about the number and variety of models that are now being or about to powered by an electric powertrain. I have no interest however in forcing others to abandon the rules of an existing event just so I can have my way and fly the technology of my choice. Have patience my friend.

Kim.

Paul Smith · « **Reply #2 on:** June 19, 2007, 03:37:03 PM »

I agree with Kim's posting 100%.

42 Volts is not a horsepower limit, but an arbitarty threshold below which death by electrocution is not (considered to be) a factor.

A 12 Volt electric starter motor can crank over a 400 cubic inch V8, so voltage is obviously not a measure of performance.

I can readily accept electric motors in the "unlmiited" events, like F2b, F4b, Class II Carrier, etc. But the use of unlimited electric power in events conceived as a refuge from unlimted money and power is completely wroing.

Rudy Taube · « **Reply #3 on:** June 19, 2007, 04:36:02 PM »

Hi Kim,

Thank you for your input. Your right, patience will be required. I was just hoping we could get a workable set of rules on "limit" events sooner than later. ;-)

Like you, I respect rules and I always try to stay within the spirit as well as the letter of the rules. But when new technologies come along that were never considered when the rules were written, then we have to work to modify the rules to fit the modern world we live in.

I am not asking any CD to "bend" the rules for electric power. As the CD in question said, he just needs some written guidelines to go by. We just have to provide him with these guidelines.

I agree with you that this is not an easy task, but it can be done. I fully understand that voltage is just one part of the power equation. I only used my example because voltage is the only unit of measure used in our AMA rulebook. This is an age old problem that we are dealing with. It has been true in racing (cars, boats, planes, etc) and many other events.

I only want to move the discusion forward and come up with a solution that is as fair as possible, and one we can all live with. This is not rocket science. The CDs will except any reasonable solution, as long as it is in writing from a governing body that will give them a solid reference to refer to when and if a protest comes up.

Like Bob and Dean said before, when they brought out the dreaded "pipe", many said it was illegal etc. .... We just need to counter the NO you can't with: here, this may help you say YES. :-)

The next time we have another battery improvement we will begin to see electric in combat (Oh the horror of it, sacrilege!!!

) carrier, speed, etc. So we will have to find a doable formula sometime. Right now the AMA 42 volts does seem rather high. But it has been accepted, and it is the present rule. They may have to allow the IC guys to go to 1.60 size engines, or bring that 42 down to 30 or??? (just kidding

).

Fortunately there really is no problem at the upper power limit setting. The line length, and plane size limits make the power limit moot. ......A .91 4 stroke, .91 piped 2 stroke, and as you said 18V elec. are all more than enough to power the largest plane allowed. Field size will continue to keep that plane size, line length limit about where it is for at least as long as we keep our spaceship so overcrowed.

BTW: I tried to look up the word "patience" in my USA dictionary, and it was not there?? I think most people in your country would say "how true!"

Again, thanks for your comments.

Regards,

Paul Smith · « **Reply #4 on:** June 21, 2007, 08:36:00 AM »

The ancient opposition to the "dreaded pipe" was not entiredly unfounded.

Turned pipes succeeded in increasing the horsepower of any given engine size. This increased speed and line pull, which triggered (well-justified) rules changes in the name of safety.

The end result was more expensive, highly complex models whose performace was dialed down to what it was before. Some progress!

-------------------------------
If we want to mix totally dissimlar equipment in the same events, maybe just using total aircraft weight (with gas and batteries) is the way to go.

Just have weight classes: "1/2A" under one pound, "A" two pounds. etc, etc.

Dennis Adamisin · « **Reply #5 on:** June 21, 2007, 06:07:42 PM »

Rudy:
Interesting question, I think Kim & Paul both nailed the answer on the equivalency queston. Heck there is big time dis-equivalence in just electric to electric much less elec to slimer!

I am sure the folks who fly P-40 had their reasons to "kill" that event (by removing the engine limit) The question I have about this new "unlimited P-???"; how is it different from just another profile stunt event event? If it is just profile stunt - with no engine limit - then your electric equivalency question is pretty much answered.

Is a "10 pt bonus for no flaps" enough to justify another event?

I think we need to be looking across the street to our RC pattern brothers; Their event has morphed into several different classes for almost any kind of bird - and nobody flies RC Pattern anymore, at least no one in any of the clubs I've belonged...

PatRobinson · « **Reply #6 on:** June 21, 2007, 09:14:48 PM »

Hi guys,

Rudy, and gentlemen I kinda started this rules stuff in the 1/2 A electric thread , so I felt responsible to try to get some accurate info on this subject so I went to the rulebook and then conferred with Keith Trostle by e-mail
to confirm and clarify what I found and what I found out was interesting and
directly effects how to frame the discussion of these rules. I put my findings
in the 1/2 A stunt thread where I started all this rules stuff. I hope it helps
everyones perspective the way it did mine. Rules or no rules, it still looked like Bob and Dick were having a blast with those little airplanes and we should all be so lucky. Till next time,
Pat Robinson

Author Topic: Rules for Electric in Size limit events? (Read 930 times)

Rudy Taube

Rules for Electric in Size limit events?

Kim Doherty

Re: Rules for Electric in Size limit events?

Paul Smith

Re: Rules for Electric in Size limit events?

Rudy Taube

Re: Rules for Electric in Size limit events?

Paul Smith

The "dreaded pipe",,,

Dennis Adamisin

Re: Rules for Electric in Size limit events?

PatRobinson

Re: Rules for Electric in Size limit events?