Maximum Motor Size

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Lee Liddle
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Re: Maximum Motor Size

Post by Lee Liddle »

boiler wrote:That has never been determined. An electric motor manufacturer suggested either the displacement (volume of the motor) or the weight of the motor would be the best factor. I plan to submit something to the AMA this rules change cycle. Any help from the electric gurus would be appreciated.

No war here Bob, just a little boarder defense.

I agree with what your answer to Todd`s original question 100%. I`ve even offered my suggestion of 10oz for the max weight of the motor. That was several years ago. Since 2007, I have flown very little Open B, because there hasn`t been enough local interest to gear up for it.

This year we have about 30 to 40 heats of B set up for contests in the N Texas area, so I`m going to spend more money and time to see what can be done with current equipment. I`ll be glad to share the results, as I always do.

What bothers me is when guys that have no hands on experience with developing or flying E Open B (and sometimes no electric experience at all) start talking about LIMITING the POWER of an electric when there is no limit on IC power. Let`s talk apples and apples.

If we want to limit the power of Open B, then let`s change the name, pick a prop and an RPM and go do it.

Limiting displacement or weight (with proper backup data) is a great suggestion. Limiting actual power input or output is of one system an not another would be unfair and short-sighted.
TEXAS ROCKS COMBAT HARD!!!

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tmelton
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Re: Maximum Motor Size

Post by tmelton »

Well I guess I would agree that when you are talking about open B it is an open class and should remain that way. My point was that even the open class limits the size of I.C. engines that can be used. It does not call out a limit for Motor size. Why would one be different than the other. I don't have any particular passion on the subject. I was just curious about why there was not limit for electrics.

After thinking about it some to measure output watts would put an unfair limit on electric motors because we don't measure output power on I.C. engines. However, there should be some sort of maximum motor weight or physical size limit that would keep things comparable to a .30 size I.C. engine.
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Re: Maximum Motor Size

Post by Lee Liddle »

I do agree Todd.

Right now it hasn`t been an issue. In the future as the power/weight ratio for electrics gets better, a limit on the size of the e-motor will be a good idea.
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sgilkey
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Re: Maximum Motor Size

Post by sgilkey »

This subject is so tiresome because some folks just want to argue instead of address the real issue. I don't see anything in Bob's original post that said he was going to propose to LIMIT POWER of electrics. He was talking weight or volume or something.....IC engines have a displacement limit of .30, there is no equivalent limit for e-motors. Nobody's figured out how to do that yet, that's why it's stymied, and reasonable discussion would be so nice.....

Let's see an e-OpenB plane win a couple of contests and then worry about it??????? What a silly statement when Open B NPS was won by an e-flier????

The fact that there is no power limit on IC engines is a specious argument. There is no power limit in AMA Q500 or Q40 racing either, but there is a DISPLACEMENT limit which is obviously a limit of sorts. If it weren't there, do you suppose Nelson and Jett would have made 45s or 50s rather than 40s????? there are choke and tailpipe limits which also restrict power but there is no defacto power limit. Even if you put similar restrictions on Open B powerplants the Jett would dominate in terms of power, it's choke and exhaust outlets are smaller than many lesser-powered engines of similar size. So what???????

What is the allowable e-motor used in Q500 or Q40 classes and how do they handle it? Simple answer is they DON'T and just don't allow it. We have tried to be as open minded as possible to allowing e to play with IC in combat while putting reasonable and equivalent restrictions on both. As technology was evolving, the 4# weight seemed to be a rough shot at a limit for Open but the motor size, volume, weight, or whatever that could be used as a surrogate for IC displacement limit was never addressed. It would be nice to try to figure out a way to do that so that the playing field is kept level. Don't bore me with statements that IC was superior to e in Open for years and nobody cared about level playing field- the technology of e was not ready for prime time, if you wanted to fly e that was an individual choice and nobody made you, you could have flown IC cheaper. If you had a jones to experiment with e, fine, you were welcome to fly and if you didn't mind the performance deficit, that was your choice. Now with equivalent performance available, what is so heinous about wanting to have an e-motor limit that is directly equivalent to an IC motor displacement limit?

I have no intention of getting into another boring and wasteful tit-for-tat on this issue, this is a "drive by" and I'll just monitor the tread. No interest in getting into arguments, but one-sided posting of "facts" has been misleading.

As a side note, at 2009 Nats we were treated to an e-system in SSC that offered performance clearly superior to the IC planes present. Only deficit of pilot skill and luck (certainly NOT a lack of underhanded tactics but I digress) kept that system from victory. We have a power system that can regulate motor power to maintin 17500 rpm in any flight regime for the entire flight. WHAT EQUIVALENT OF THAT IS THERE IN THE IC WORLD??? I've heard it agued that ICs unload more in a dive, while this system will restrict rpm increase in such circumstance. WHO CARES, how many cuts are made in a screaming power dive, versus how many are made in tight (high power load) turns and climbs, where an rpm-hold system will be/is a clear advantage??? We opened to door to e for SSC, the ability is there for it to outperform IC, fine we made our bed. It would be nice to get some kind of equivalent restrictions on Open B power systems before the dramatic ongoing evolution of e-power systems (NO SUCH EVEOLUTION IS OCCURING ON THE IC SIDE) overtakes us.

All the side arguments that are, and will be, regurgitated on this subject avoid the basic, simple, and obvious question. In an event (combat) where power is clearly desirable, and where there are clear and explicit rules designed to SOMEHOW LIMIT POWER (ie displacement limit in open B), where is the EQUIVALENT restriction on e-motors? DON'T SAY "WEIGHT," weight is already a limit for IC, and as you so rightly pointed out, is INDEED a factor which contributes to making the Jett essentially a non-factor in Open B, as it puts many conventional planes OVER WEIGHT.
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Re: Maximum Motor Size

Post by sgilkey »

meant to mention in my previous rant that if there were no displacement rule in Open B I would certainly have used 32s. Not that I wanted the extra power, but for essentially the same weight I could get as much or slightly more power from a bone-stock 32 than a piped 25, with no hassle with the cost and fragility of MCP, pressure fuel systems, etc. Anvil like reliability and durability and throttlability, no brainer. If I wanted bodacious power, strap a pipe on that bad boy. But I can't get UNLIMITED power at 3.5# max weight because I have a DISPLACEMENT RULE. I am limited to a .30 and that is a real restriction that forces certain choices.

The Jett 30 is not a real choice for most. Just strapping it on adds over two ounces. Unless you reconfigure your nose moment (most folks want to just bolt it on), you need to add another ounce of tail weight. Then due to the horrendous fuel consumption you need 8 ounces, which adds another 2 oz. to takeoff weight. So you are now carrying 5 more ounces and that will definitely show up in a larger turning radius. Small turning radius = better cutting ability, much more than straight line speed. If straight line speed were the answer, you'd see small winged rockets in combat, but you don't.

I keep telling myself I am going to experiment with setting up a Jett so I can get 6 minutes on 6 oz, and find a simple method to shorten up a conventional plane to get my BP right without tail weight. Then I only get a 2 oz penalty (livable), maintain most of my turn without giving up a lot of the straight line potential. As to the purchase price, well, buy a used one (then put new bearings, head, gaskets etc. in it....) and you can save, what, $25 on that price, ask me how i know..... One of these days I'll get to this, it was supposed to be a winter project but winter's over and it ain't done yet.....

My view of the standard way to make a jett work is to purpose build a plane with the right moments to get the BP right, and just about nobody wants to do that for an expensive motor that might get damaged. If they WANT to, they can do it, and not grumble about how the 3.5# limit makes them take out armor to do it. Anyway to me bottom line is this whole "the IC guys have Jetts and Foras and no power limits" is just not much of a counterpoint. Those engines have been available for years and practically nobody is using them and they aren't winning NPS, for various reasons. e-tech and power density are improving while costs are coming down, a circumstance not seen in IC.
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Re: Maximum Motor Size

Post by Dane McGee »

............. :shock: :shock: :shock: :shock:
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Lee Liddle
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Re: Maximum Motor Size

Post by Lee Liddle »

Scott, you need to go back and read the whole thread. You have clearly misintrepreted my posts, but that happens when you jump into the middle of a disscussion like that. No problem, I`m use to it. I only read about half of your post too. Chill out man. :roll:
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Buttercup
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Re: Maximum Motor Size

Post by Buttercup »

Bob
There is no war. I would like to have a chance to experement a little before we make a rule on the matter. The year Lee won, he was using inrunner motors. So we need a little time to see what outrunner might be the best. We need to have more folks than me and Lee experementing.
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Re: Maximum Motor Size

Post by Buttercup »

I wrote the last post without reading page 2. I need more time on this forum, And I sure wish I could type.
YALL NEED TO CALM DOWN
I am a firm believer it doesn't matter what kind of plane the top pilots fly. they are going to win.

Now I've posted about my limit.
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Re: Maximum Motor Size

Post by EK »

One only has to look at the ads in the magazines to see what direction our chosen hobby is heading. Last year, almost half of the entrants I competed against were electric. Did I have an advantage? Did they have an advantage? The advantage, if there was one, wasn't in the powerplant. For SSC, the prop/rpm/weight keeps it all even enough. Open B should be left alone and see what falls out just using the weight limit. My .25's have enough power for the vertical and I believe too much speed is actually a detriment (unless everyone is flying the speed of heat). Open is open...let's not slam the door shut before we're even out the door.
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Re: Maximum Motor Size

Post by o1moregil »

EK wrote:One only has to look at the ads in the magazines to see what direction our chosen hobby is heading. Last year, almost half of the entrants I competed against were electric. Did I have an advantage? Did they have an advantage? The advantage, if there was one, wasn't in the powerplant. For SSC, the prop/rpm/weight keeps it all even enough. Open B should be left alone and see what falls out just using the weight limit. My .25's have enough power for the vertical and I believe too much speed is actually a detriment (unless everyone is flying the speed of heat). Open is open...let's not slam the door shut before we're even out the door.
Amen.
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Re: Maximum Motor Size

Post by Lee Liddle »

Evan and Gil, thanks. Since you guys are the guys that I "experiment" on :lol: your opinion means a lot to me. If the total lack of respect that my personal Troll gives me, was what I saw at our N Texas contests, I would probably abandon flying E Open B and just accept that the only "hair on fire" event that we have left would eventually go the way of the dinosaurs.

I get a kick out of flying electric powered planes, don`t know why, I just do. But I also know that at some point, electrics will be the only choice we have to power our toys. That`s another reason I put up with the grief that people like Scott Gilkey dish out here on the forums.

Last year at LSN,my friend, Mike Wilcox, who is a current member of the US F2D combat team and a past F2D World champion helped me in the pits during Open B. He watched me burn up motors, puff batteries, fry ESCs, and come down early in almost every heat. He asked me, "Lee, why do you fly electrics in Open B? What kind of advantage is it?" He`s super competitive, and naturally assumed that there must be some advantage, or I wouldn`t be doing it. When I told him that I do it because I think it`s cool and I like the challenge, he just looked at me kind of funny and said "Ok, dude. I just wondered".
TEXAS ROCKS COMBAT HARD!!!

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Re: Maximum Motor Size

Post by Which_way_is_up »

Lee Liddle wrote:Evan and Gil, thanks. Since you guys are the guys that I "experiment" on :lol: your opinion means a lot to me. If the total lack of respect that my personal Troll gives me, was what I saw at our N Texas contests, I would probably abandon flying E Open B and just accept that the only "hair on fire" event that we have left would eventually go the way of the dinosaurs.

I get a kick out of flying electric powered planes, don`t know why, I just do. But I also know that at some point, electrics will be the only choice we have to power our toys. That`s another reason I put up with the grief that people like Scott Gilkey dish out here on the forums.

Last year at LSN,my friend, Mike Wilcox, who is a current member of the US F2D combat team and a past F2D World champion helped me in the pits during Open B. He watched me burn up motors, puff batteries, fry ESCs, and come down early in almost every heat. He asked me, "Lee, why do you fly electrics in Open B? What kind of advantage is it?" He`s super competitive, and naturally assumed that there must be some advantage, or I wouldn`t be doing it. When I told him that I do it because I think it`s cool and I like the challenge, he just looked at me kind of funny and said "Ok, dude. I just wondered".

Can we get a second Amen!
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Lee Liddle
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Re: Maximum Motor Size

Post by Lee Liddle »

Thanks Bud! See ya this weekend.
TEXAS ROCKS COMBAT HARD!!!

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David Drowns
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Re: Maximum Motor Size

Post by David Drowns »

Which_way_is_up wrote:
Lee Liddle wrote:Evan and Gil, thanks. Since you guys are the guys that I "experiment" on :lol: your opinion means a lot to me. If the total lack of respect that my personal Troll gives me, was what I saw at our N Texas contests, I would probably abandon flying E Open B and just accept that the only "hair on fire" event that we have left would eventually go the way of the dinosaurs.

I get a kick out of flying electric powered planes, don`t know why, I just do. But I also know that at some point, electrics will be the only choice we have to power our toys. That`s another reason I put up with the grief that people like Scott Gilkey dish out here on the forums.

Last year at LSN,my friend, Mike Wilcox, who is a current member of the US F2D combat team and a past F2D World champion helped me in the pits during Open B. He watched me burn up motors, puff batteries, fry ESCs, and come down early in almost every heat. He asked me, "Lee, why do you fly electrics in Open B? What kind of advantage is it?" He`s super competitive, and naturally assumed that there must be some advantage, or I wouldn`t be doing it. When I told him that I do it because I think it`s cool and I like the challenge, he just looked at me kind of funny and said "Ok, dude. I just wondered".

Can we get a second Amen!

Amen,

You have to admire someone who just wants to develop any part of class by trying new stuff and pushing it to see how far it will go. I'm not on the electric wagon right now but without those who have a passion to wring it out until it works there would be no one advancing the sport. Thanks Lee for the push you give it along with some others so if I do find myself with that electric urge that just won't go away I'll have a better idea of how to set it up. :wink: Keep it up. We're watching.
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