rm

My Feedback: (27)

Let's look at this from another angle. You guys are using a motor which weighs 3 oz lighter than a hacker, batts which are 4-5oz lighter, a smaller prop say 1oz. That's a half pound difference right there. Your also running your batts at 13c @ 65amps, prob using up close to your packs capacity each flight, and though supplying sufficient power, prob not close to the hackers performance envelope. It will be interesting to hear how long your batteries last using them this hard.

can773

My Feedback: (1)

I use around 65% (3200-3400) of total capacity in flight...average current draw in flight based on that usage is 22 amps (4.4C)

Peak static draw and peak in flight draw will not be the same, I have heard anywhere to upwards of 20% less in flight....I will be testing this to prove what it is shortly.

The packs are barely warm to the touch after flight.

Performance is as good or better than my 140/160DZ's so why would I need more?

Eric.Henderson

You all might think that this weoigt issue is all about electrics but you might just be forgetting the bi-plane advantage?

Eric.

rm

My Feedback: (27)

Your really easy on your throttle. I doubt the average flyer would match that. I'd be very interested in your in flight numbers, as I've never seen any actual just guesses.

Personally, I'd like to see the way electrics are weighed, without the battery, and keep the 11lbs. This would allow us to run batteries well within c ratings, hopefully extending battery life and lowering the associated costs.

I don't buy the biplane issue. They might show up for a while, but they're a major pain in the ..... If it was such an advantage you'd see them dominating IMAC as well, but you hardly ever see one the whole season.

can773

My Feedback: (1)

Drop me you email address, I will email you my spreadsheet that I am using to keep track of the packs...it has all the pertinent data regarding flight time/consumption voltage etc that I have gathered on my model to date.

[email protected]

Here in Canada we went to weighing the models without batteries for this year, I guess time will tell if this is a help or not.

ERichard

2000+ flights!! I seriously doubt that! Think about it....if you flew that plane EVERY weekend (both Sat and Sun) for a full 5 years you would have to put an average of about 4 flights per day (Sat and Sun) to get to 2000+ flights. AND you have been through 12 two meter planes in the past 6 or 7 years.....That's an aweful lot of flying considering there is a winter season in Canada

Kind of remids me of that Monty Python skid...."Luxury! We lived in a shoe-box in the middle of the road....."

All in good fun
-Erik

rm

My Feedback: (27)

Sorry Chad,
I meant the testing numbers you're going to come up with. The static vs in flight #'s. I wasn't clear in my post and have never seen anyone post those before.

can773

My Feedback: (1)

I have 3 seasons on that Enigma and I fly almost everyday from March through to November....Calgary has far superior weather than most of Canada.

I didnt fly my other planes as much as this one (mostly around 500-800 flights before I got rid of them), I just like this one so much I kept flying it...and I still will until she blows apart in the air LOL

can773

My Feedback: (1)

Ahh ok, should have it by the end of next weekend, I will post it up then.

Was out last night, testing static ground RPM before and after the flight, dropped 140 rpm after the 10 minute flight time....not to bad, didnt seem to notice it.

patternflyer1

My Feedback: (11)

It seems to me that we have rules in pattern and have had for a long time. Now electrics jump into the picture and some people flying one want the rules changed to suit there planes. Weighing the planes without the battery. hmm. Well I for one would love to go to a gas motor. So should we weigh it without the motor? Because I need the rules changed to suit my plane? Now this being said, I am not against change and am not trying to start the normal thread controversy. I am offering my opinion on the thread subject. Change can be good. But should rules be changed when new technology comes out. I personally think that there should be a period of time after new technologies come out that there should not be any change so that there is time to produce the parts needed to get the plane under weight and at a reasonable price. This way, we are not jumping to change rules too early. I mean, its only been a couple of years with electrics now. When people first started using them they were saying it was virtually impossible to get the plane in under 11 lbs. Now look, most people seem to be having no problem. Yes the batteries are expensive. But look at the fuel money saved. Plus, this is not an inexpensive sport and everyone knows it. And yes it is the initial money that's keeping me from building an electric so I understand where most are coming from on this. But if we wanted an inexpesive hobby we would have picked flying a kite instead. lol.

rm

My Feedback: (27)

Hey, I'm down to $100/flight!

The way the rules are written its more of an interpretation, than an enforcement of a rule.

patternflyer1

My Feedback: (11)

Now that's funny!!!!!!!!!1[:-]

flywilly

My Feedback: (121)

Hey patternflyer1,
excellent point. Electrics have been around in pattern longer than most realize. Dave von Linsowe had an electric USA Star several years ago. I think he planned to fly it in the team trials in '97 or '99, but didn't get to fly it enough to be comfortable competing with it.
I bet gas engines could be made to be competitive under the current rules. Takes a lot of work and some cash as well as motivation. Given the choice I'd go electric before going to gas.
In a few years we'll be the beneficiaries of the pioneering done by the top level fliers today - top level equipment at an 'affordable' price!

patternflyer1

My Feedback: (11)

Thanks.

I'm glad my point was seen as something that wasn't bashing the idea. This is just how new technogies get started. I mean, look at how small computers, and cell phones are now compared to years ago. I think I would also go electric first also. I'm building a PAC patriot right now ( I know, I'm behind on the times, lol) and I'm thinking of going electric in it. I'm just trying to find out all the costs right now. I would also like to find a gas motor but I don't think that would happen for the weight..

Chris

can773

My Feedback: (1)

Hi rm

We tested both a 18.5x12 (cut down from 19x12) and a 19x12, seems that the peak in flight draw is about 8-10% lower than the peak static draw measured before and after a flight. I was running about 65 amps static and 58-59 amps in the air. This was done right at sea level, on a cool damp air day (12 celcius)....it may vary a bit on a hotter higher altitude thinner day but I think its pretty much in the ballpark for most situations. Static draw was up about 2 amps from my home field which is 3500' asl and usually very low humidity.

Red B.

Being a non-American perhaps I shouldn't comment on this topic, but I will do it from an international perspective (FAI).

In F3A the basic rules for the aircraft are:

Maximum overall span .................................................. ..................................2 m
Maximum overall length .................................................. ................................2 m
Maximum total weight .................................................. ...................................5 kg without fuel
Power source limitations: Any suitable power source may be utilized except those requiring solid
propellants, gaseous or liquefied gaseous fuels. Electric powered model aircraft are limited to a
maximum of 42 volts for the propulsion circuit.

I think that one objective of the rules should be to keep the costs down. This will allow more people to compete on equal terms.

IMHO there is no need for a maximum weight limit. We all know that, as a general rule, lighter aircraft perform better. Thus there will always be an incentive to build light.
Doing away with the weight limit altogether will however lead to rising costs, because more expensive construction methods/materials will be needed in order to achieve the lowest possible weight. Therefore, it seems reasonable to impose a lower weight limit chosen to allow aircraft built with traditional (read inexpensive) materials, e.g. balsa sheeted foam core wings and balsa/ply fuselages, to compete. Also, by imposing a lower weight limit measured without fuel/batteries, the question of "wet weight" will be a non-topic.
My reason for the "dry weight" limit is that this will allow more people to try electric propulsion without having to invest a lot of money in expensive battery technology.


/Red B.

rm

My Feedback: (27)

Thanks for the info Chad. Looks like most guesstimates were within reason. 8-10% would put me comfortably within my batteries rated range. Hope they last a couple of years.

ExFokkerFlyer

My Feedback: (4)

Upping the weight limit just a pound would open the flood gates for people wanting to try gas engines. Right now, the engines are just a bit too heavy to be used in off the shelf kits and make the weight limit. I am sure it could be done and it has been done really... but can it be by the average pattern builder?

Not only that, but people would not be hamstrung with converting glow ships to electric if they so desired. People have done it successfully sure, but how many 10.5+ lb glow airplanes are out there that could have thier performance increased with electric but can't without exceeding the weight?

So what about biplanes coming into the market... Whoever said it before was right, they would come in for a bit, and then leave again... the simpler designs keep coming back around.

As far as changing the rules to fit technology... this is nothing new. Two words "four stroke". The limit was .60 for years... then it was upped to 1.20 because four strokes didn't have the power. Then we saw OS, YS, Webra, Saito, Enya etc. flood the market with 120s...

Why not change the limit? Lighter flies better... the only thing you are really doing is allowing more choices into the mix...

In the end, gas will probably win out. It's cheaper, cleaner (than glo)... the only real down side is vibration.

that's my 1 cent

cygnet

My Feedback: (33)

Here here I fully agree