Stupid Newbie (to pattern) Question
 

Why are wet fuel models weighed without fuel but electrics are weighed with fuel?

Just curious if their is a logical reason that hasn't jumped out at me.

RE: Stupid Newbie (to pattern) Question
 

I guess you could discharge the batteries before weighing but I don't think an electrical charge weighs much.

It should be interesting to read all the responses to your question. If I remember correctly there was a pretty good debate over this a year or so ago. My take on the arguement was that the battery was a holdiong tank and the electrical charge was the fuel that was depleted during flight as the glow fuel is for IC engines.

If my memeory is failing me (and it probably is) I'm sure someone will correct me.

RE: Stupid Newbie (to pattern) Question
 

Not a stupid question at all-- but one that has torn at the pattern community for some time.

Of course there are all the funny thoughts about how we electric flyers are welecome to weigh our airplanes with the batteries drained.

But really, I haven't heard any real logical reasoning.

It isn't something decided in the states, it is really an FAI issue, which is an international forum.

RE: Stupid Newbie (to pattern) Question
 

The best respond I have seen is this "fuel tank can not be removed when checking the weigth"

Regards,

Vicente "Vince" Bortone

RE: Stupid Newbie (to pattern) Question
 

Because you can put different weight of fuel in a tank....you cant put different weight of electricity in a battery.

RE: Stupid Newbie (to pattern) Question
 

The correct respond (if F3A) is because is in the rules. Check this documents:

http://www.fai.org/aeromodelling/documents/sc4

Weight has to be checked with batteries installed.

Vicente "Vince" Bortone

RE: Stupid Newbie (to pattern) Question
 

Vincent is right. This issue was resolved during the last rules cycle. Previous to that electrics were weighed without batteries, but that has now changed and batteries have to be in the aircraft at time of weigh in. I don't think this is much of an issue any more. Many electrics are now coming in at 10.5 lbs or less. Most glow planes are easily under 11lbs, even as large as they are now. The FAI has also added 1% deviaton allowance, don't quote me on the amount, but it is basically 1-2oz that if you are in that are you aircraft is considered legal to allow for possible deviations in scales,

Arch

RE: Stupid Newbie (to pattern) Question
 

g-day
this is a very silly Q. but does electric actualey weigh anything? "not including the battery"
never even thaught of that until i read this forum.

simmo

RE: Stupid Newbie (to pattern) Question
 

The fact it is in the rules is why I was asking the question. It just doesn't make sense to me. (I fly both wet and electric aircraft). While the comments about electrons don't weigh anything are cute, they really don't apply. In my tiny limited view, it seems the battery is equivelant to the fuel and tank.

To me, it seems the rule could give an advantage to non-electric aircraft on breezy days since they can carry the additional weight of the fuel.

I was just curious about the rationale behind the rule, like I said, I am a newbie in the pattern area (just got my first pattern plane!)

I appreciate all the feed back, thanks guys!

RE: Stupid Newbie (to pattern) Question
 

This is quite a tricky thing, the way it is right now works fairly well. I don't think I have heard many of the long term electric guys complaining there is an advantage or disadvantage to the current rules. Its not rocket science to make weight as it stands today unless you pick all the heaviest things you can find.

I also don't see a lot of glow guys stuffing 50 oz fuel tanks in their plane so they can take off at 14lbs, that just doesn't make sense, and changing the rules to weigh without batteries would put a huge discrepancy in T/O weight between glow and electric since the batteries are a major percentage of the weight of the model. That doesn't make sense either.

Personally I like it the way it is now, and if I feel I should have a higher wing loading because I am at 11lbs at T/O instead of 12 lbs, then I should use smaller wings!

RE: Stupid Newbie (to pattern) Question
 

Can773,

Thanks for that insight, more for me to digest.

Like I said, I am new, actually I guess I am not even new until I actually get the plane flying and practice and then enter a contest. Maybe I should say "I'll be new in a year!" :D

RE: Stupid Newbie (to pattern) Question
 

I think it's a silly rule in the first place. Planes have grown to be these huge beasts from several years ago. The 2x2 size frame is still the same, but the fuse's are huge.. I don't see an advantage to having a weight rule. Just size and sound rules.
Just doesn't make sense to limit the weight when we all know that in a 11 pound 2x2 plane will fly better than a 20 pound 2x2. Even if the rule went away, are we going to see people building heavy? I would think we will still shoot for something in the 10 pound range.. I don't like the speed limit either... But, rules are rules.. :D

Chris

RE: Stupid Newbie (to pattern) Question
 

The battery is the tank...

...the electrons are the fuel.


Pretty straight forward I think.

RE: Stupid Newbie (to pattern) Question
 

That's just silly. It's a different technology than glow.. A battery is a battery. Not a tank, not fuel. [sm=spinnyeyes.gif]
I'm not saying the rule should be changed, I'm fine with it. Makes me build lighter, which is fun..

C

RE: Stupid Newbie (to pattern) Question
 

Friends
Two days ago I posted the same question with the one that started this thread in a Greek forum http://www.aeromodelling.gr/ForumS/i...p?topic=5358.0
Rules are rules ....BUT... they exist for several reasons and, in my opinion ,most are trying to normalize the various participating models to some maximum standards not only for the sake of safety but for the sake of justice as well.
If someone agrees on the above mentioned then I believe that he should also agree that it is not right to have this discrimination between wet and electric planes.
The obvious and right way to go is to measure flying weight at least as a first step in correcting the injustice.
I remind you that even then the two different propulsion systems have different attitudes especially during the end of flight for the wet planes due to fuel consumption(they get lighter so they can climb more easily).
One major difference of the two types is that the amount of energy that a wet plane carries is HUGE compared to the electric one because it can use it's maximum power up to the last drop of fuel.We all know that the electric one can have the absolutely max. power only at the beginning of the flight since the battery's voltage is dropping thereafter.
So what I am saying is that at least we can make things more just if the weight rule changes to weigh wet planes WITH fuel.

The way to achieve this is by making a well documented and reasoned proposal to the appropriate CIAM subassembly and by hearing various opinions and suggestions this could happen in near future.

Of course by now you already understood that I fly electric F3A but as many of you already posted I'm not yet affected or pushed to the limit of 5Kg (at present time).It's just a matter of injustice due to discrimination.

Bill Papadopoulos

RE: Stupid Newbie (to pattern) Question
 

OK, let's take this "weigh 'em full" argument and run with it. I have a 20 oz tank on my 140-DZ flying intermediate. I burn about 1/3 of a tank during a contest flight, the extra capacity is there for practice. So when I weigh-in, do I get to put in only 7 ounces of fuel? I'm sure the response will be something like "Sure, but that's all you get to put in before each flight." Who's going to police that? People who get into electric know the rules. If they don't like them or feel they can't win with them, then don't fly electric for competition. Also, lets look at the weights of the powerplants. A Hacker C50-10XL weighs 14.7 ounces (18.6 with gearbox). A YS 170-DZ weighs 33.6 ounces!!! And I can bet even though I don't fly electric, the speed controller does not make up the 15-18 ounces of difference. Also, lets look at it this way, since those weights bring to light another important point: if a glow-powered aircraft runs out of fuel, you don't lose control and usually safely glide to a landing, if the battery falls out of an electric airplane, you'll be lucky not to crash shortly thereafter. My point here is that the batteries are an integral part of making the airplane flyable because they are required to properly balance the aircraft, a glow-powered aircraft is still flyable if the fuel is not in it. I'm sure all these points were discussed ad nauseum when the rules were decided on. Bottom line, the decision was made that electrics are weighed with batteries, glow planes without fuel.

RE: Stupid Newbie (to pattern) Question
 

Interesting points. You'll never see it though until (if) you fly electric. And I don't care if you ever see it, don't get me wrong. As stated, I'm fine with the rule even though with new technology should come rule changes at points. And it will, someday. Face it, technology is going to change, always. Do we keep the same rules forever? Rules become outdated at times as technology progresses. But for now, we are where we are. Seems to me that the glow guys like their extra weight. Landing with a half tank of fuel is alot of penetration in the wind. And I know several that do it on purpose. Heck, I used to..
Rules are rules, gotta live with em for now.. :D

RE: Stupid Newbie (to pattern) Question
 

mjfrederick fisrt allow me to say that in both cases of running out either of fuel or battery power(motor battery) both planes are going to glide with whatever result.This happens because in the electric plane the receiver/servo system has it's own dedicated battery, regulator etc. just as it is used in wet planes(we are not talking here about small electrics that use BEC).
Now for your question that you would get to fly with only 7oz. of fuel the answer should be YES just as an electric plane has to fly with total weight of 5Kg and you should match this as itis the same weight rule applied for both planes BUT with the discrimination of w/o fuel for wet ones.Dont you see that something is not right?
"Who's going to police that?" is easily answered by weighing your plane full of fuel at the technical ckeck in and be under 5Kg +1% as the weigh rule dictates.
If on a subsequent check your plane is found beyond this limit then some penalty could be applied ,I suppose (because there is an advantage beeing heavier on windy days as patternflyer1 mentioned).
The commonly used argument that batteries '' are an integral part of making the airplane flyable because they are required to properly balance the aircraft'', is not correct because it is perfectly feasible to design a model with the battery exactly on the same spot(CG) as wet planes do with the fuel tank.In addition which rule is dictating anyone where to put the various weights?
If we expand on our thoughts we can say that exactly as you take out the weight of fuel on wet planes you could take out the weight of the motor batteries perhaps allowing the net weight of the fuel tank to be taken out also for wet ones.

Again rules are rules and we follow them but shouldnt somebody question something that seems wrong just like we do it here(debating friendly I hope)?
Bill

RE: Stupid Newbie (to pattern) Question
 

g-day
i do not fly patern but this is just a sugestion
why dont they have 2 diferent classes 1 class for electric and its own rules and 1 class for wet and its own rules then there would be no issues about all of this.
happy flying

simmo

RE: Stupid Newbie (to pattern) Question
 

You completely missed the point. I didn't say anything about running out of battery power, I said if they fell out of the aircraft. The electric aircraft requires the batteries to be there, or else the CG will be somewhere behind the trailing edge of the wing. In theory you could tow a glow-powered pattern aircraft with no fuel in it up to a reasonable altitude and glide it to the ground safely, I'd like to see you do the same with an electric-powered aircract without the batteries in it. The glow airplane is still a flyable airplane without the weight of the fuel, the electric is not flyable without the weight of the batteries. I don't care about whether or not a BEC is used, it has nothing to do with being able to control the servos.

Again, you missed the point, are we here to fly, or are we here to weigh aircraft before and after every flight? Gimme a break. I work for a government agency, I get enough buraucracy at work. If you institute rules that will put a greater burden on those running the contests, they will simply ignore them, or stop running the contests.

I'd like to see how disgustingly long the nose on that airplane would be. Either that, or you'll end up with a half pound of ballast in the nose to balance it. You could also shorten the length of the tail, but then you end up with a sport plane with a short tail moment. Not much of a pattern airplane there.

I've come to a compromise: I have no problem weighing in with a tank full of fuel (I'll just put a smaller tank in for contests), and will be happy to do it the day electrics are required to put the batteries on the CG.

RE: Stupid Newbie (to pattern) Question
 

There would only be 3 or 4 people at the electric contest, and probably none of them in the same class.

RE: Stupid Newbie (to pattern) Question
 

Why are you so angry with electric pattern? ;) geez
It's technology man. I can understand you trying to push what you believe in. Maybe if you were to give electric pattern a try, you would see why it isn't totally fair. I don't think electric rules should be different than glow, but the weight rule is silly. It should probably be 15lbs. Lets more people fly pattern with their IMAC planes.. It would bring more people to pattern and make things more challenging for all as there are some good IMAC pilots. Lets ask this, what does the weight rule really enforce? Not the size, or shape of the plane. Not how much noise it makes. What does it enforce?
BTW, on any of my electrics so far, I could have built them to have the batteries on the cg. I'd just have to shift things forward. Wouldn't be a problem. My batteries are usually pretty close to the cg. Not sure why you are making a big deal outta this one. If my batteries were to fall out? Well, guess what, they don't.. And again, it's advancing technology. That's just sillyness!!
So let me ask you this, can I mount a tank in my electric and fill it with fuel for those windy days at the nats? This would be fair IMO.. I've been told it wouldn't be allowed. But I may try it at the nats this year so I have something to write about in the Kfactor. :D Oh, I gotta get working on this!!

C

RE: Stupid Newbie (to pattern) Question
 

I'm not angry with electric pattern, just making a case for the weight rules as they are since someone asked why they are that way. I don't care either way except to say I don't think glow planes should be weighed with fuel in them. If I was angry I would be typing in all caps.[>:]

I have seen many battery installations that could fall off the aircraft in flight (mounted in the belly pan), and I even saw one where the battery came loose inside during flight, and shifted towards the back of the airplane making it almost unflyable. Yes, with some serious re-arrangement of radio gear, the batteries can be put on the CG, but most people aren't going to mount their servos that far forward.

I would love to see an electric aircraft with a fuel tank in it, wouldn't bother me, but most of the time, don't they catch you at the end of a flight to check weights and take measurements? You're gonna have a tough time convincing them to let you drain the fuel from your electric-powered aircraft, but give it a shot. I'll be looking forward to how the rulewatchers handle that one!

I'm looking forward to the day we have hybrids out there, get the best of both worlds! :)

RE: Stupid Newbie (to pattern) Question
 

Some time back on the [link=http://nsrca.us/]NSRCA[/link] forum list an individual posted the following that summed up the weight rule debate best for me.

Here’s the quote:

“In my opinion, ANY change in the rules will be exploited. And why does there need to be equity or parity of equipment??? In ANY competitive sport there are limits that effectively define what is and is not competitive. Should wood propellers have a special rule to help them be more competitive? They’re cheaper! That’ll help get more people into pattern if we give a scoring bonus to people using wooden propellers. Sorry, that’s being a little obnoxious, but that’s the way this feels. I’d love to use cheaper, lighter paints...but the burden of nitro is making things fuel proof. Everything I use on a plane is decided based on what will be either cool, competitive, or cost effective. It’s rare that I get to have all three. Where’s the proposal to increase the weight for Gas engines since none of the current designs are competitive at the current weight? Talk about saving some money in pattern...whew...$3/gal vs $20/gal times 50 gal a season…” end quote.

Altering the weight rule can and will affect every pattern competitor US and internationally, some negatively some positively. Rules should only be changed unless duly warranted to level the playing field for the majority. Lobbying a rule change to appease a minority to ease their effort to make weight with e-power is not in the best interest for the majority. Instead apply energy and pressure on the vendors who supply motors, ESC, batteries, airframes, accessories etc. to evolve their technology to meet the objectives of the pattern community.

Personally I’ve witnessed several local competitors newly construct and retrofit existing aircraft with e-power and make weight. Making weight with either IC power or e-power requires planning and application of thoughtful building techniques. Everyone’s goals and interest are different as to why they do pattern. No matter the level of interest or enjoyment one receives from pattern some effort large or small has to be applied to compete within the current rule structure.

RE: Stupid Newbie (to pattern) Question
 

Well said, Glen.