texzen1

I just finished my first 2m pattern plane after studying the subject a while.... Here is my delima. I decided to go electric. The electric package, engine 5330, speed control 100A and batteries (2x5S/5000) weighs 4.77 lbs. Built the plane (Fortuna) up in mock-up and it comes in at 13.95 lbs with all the stock gear. My goal is sportsman class with the 11.27 lb limit if i read correctly. Granted some of my stuff is not F3A comp stuff, but i have bought all weight comparable stuff, some even lighter. I have no real heavy hardware, comparable weight servos to what the f3a guys are using. I have calculated that i can go to carbon wing spar, and landing gear, spinner and 4000mah batteries but im still going to be 12.5 to 12.7 lbs. Where am i going wrong? I weighted my initial airframe and its comparable to the stuff for sale on the F3A unlimited site (although its not clear if the are including landing gear, wing tubes and spinners which come with some of the kits). I also cannot afford any of the redundancy or bells and stuff i like (voltage regulator and redundant rx batts, beef ups in landing gear or twin elevator servos).

No that i have honed in on this problem and have researched it, i am afraid i made a mistake by going electric. I find an underground cult that says the AMA and FAIA rules are badly in need of revision due to the new electric wave. THEY say keeping electric 2m new wide body style planes under 11 lbs equates to about a 6500 dollar (carbon everything) airplane. Making this a rich mans sport. (Rules as i read them do seem unfair to me that a gas planes is weighed without fuel while an electric is weighed full of batteries. I have calculated that this plane would be right at 11.75 lbs with a YS170 and carbon wing tube and landing gear, still minus a header. Are my assumptions correct or am i missing something....... Also confusing is i have run across some club guys competing in local AMA club events and asked about weights on planes and i get answers like 12 to 14 lbs. When i ask about the 11 lbs limit the just say no way to get there without spending a fortune and risking your plane to zero redundancy and substandard light-weight hardware and the people throwing the event know that don't go by the weight rules knowing its messed up and they would be seriously limiting the number of competitors or making it a 110 size max plane event.

Please advise....

A couple notes to help with advise....

Engine Hi Max 5330 675 grams
Batts Tunigy 10S 5000 (2x 5s) 666 grams each.
Plane, Fortuna 2m - Foam Balsa sheeted wings, stab and tail, balsa ply fuse with monakote.
Carbon pushrods, nylon/aluminum horns
Plane came with aluminum wing tube and gear. Can save .6 lbs by changing them to carbon....

texzen1

I know i'm not a professional like most in this forum.....i just want to compete in local sportsman events and don't know where to go for information....it seems that this is an all weight driven sport where you have to consider everything down to the weight of the covering and length of wire used.  Seems strange to even have maximum weights so close to the limits of technology in a sport that is supposed to be fun....  even Formula 1 has gone to minimum weights to keep it from being a " whoever can afford the most carbon and titanium wins" sport.

petec

My Feedback: (58)

Is it an ARF, Kit, or scratch built? There is a LOT of weight to be saved in using light wood, foam and not using too much glue.

DaveL322

Tex,

First thought - is your scale accurate? 14 lbs electric or close to 12 lbs glow is extremely heavy. For a given plane, I've never seen a conversion from glow to electric add 2 lbs, and I've never seen 1.25 lbs saved by replacing components with CF.

I'm not familiar with the Fortuna, but have you compared kit component weights to other planes on the RCU forums? There are plenty of kit, ARC, ARF, and VRTF pattern designs currently available today that can be completed <11 lbs without using substandard equipment or spending $6500. There are plenty of build threads on RCU that list airframe component weights for kits and ARF plattern planes, as well as weights of equipment used to complete the builds.

I seriously doubt more than 10% of the pattern planes actively competing across the US weigh more than 11 lbs with reasonable equipment, and absolutely shocked if any came close to 13 lbs.

You'll find plenty of people on RCU willing to help, the place to start will be with the weight of airframe components.

Regards,

texzen1

It was an ARF (Hardly....lol... have like 200 hours into the fitment, detail and assy).   The airframe itself (everything that came in the box) minus the iron wing tube and gear struts) came in at like 2700 grams.  Comparable to the advertised weights of some of the planes on F3A unlimited site.   But who know what components they are weighing....  i think...i could hack and drill probably 200-300 grams out of it but i think i would be compromising the strength and life...  there does not seem to be an abundance of glue or plywood used.....

texzen1

Dave...thanks for the reply.....scale is industrial electronic and calibrated with standard at 11 lbs.

toddblose

My Feedback: (10)

Some of the weight is in the Batteries at 666g x 2 puts you at 1332 and that is very heavy, You can get the 15c packs that are lighter
or go with the F3A Unlimites packs that weigh 1188 that will save 5 oz.. But not sure on the other weight you need to get rid of..
What do the wings weigh RTF? and then the fuse.. maybe we can see where the weight is a problem. I can let you know
the weights of my planes to give us a starting point

Hokie Flyer

You can also go with Turnigy Nanotech 25C 4000 mah packs.  They have enough juice to fly the new Masters pattern with about 1000 mah left after the flight.  They deliver good power and come out of the plane cool.  CA Models Genesis, Dual Sky 6360-12 Motor, 55 amps at full power.  These are 100amp continuous discharge batteries so they don't have to work hard.

The biggest problem is catching them in stock at HK.  BTW, the higher discharge Nanotechs are alot heavier and cost more. 


Rob

shepga

Tex,
I see your from Texas and from your earlier post you would like to get started in pattern. We don't weigh aircraft at competitions in Texas or LA. If you show up to any competition in Texas with a 14lb plane to fly sportsman you will be greeted with a smile and shown the direction of the registration table. I would suggest you do what you can to get the weight down but please don't spend allot of time, money or effort to do so. However, do spend copius amounts of time and effort flying and practicing with your plane. If you end up liking pattern then I guarantee you this Fortuna will not be your last aircraft. When your ready to get your next plane I'll bet things will be a little different.

texzen1

Yes on the 666 gram batts..Although i saw some F3A guys using my exact batt packs.  .i figured i could even get away with 4000 mah packs and drop to 1250 grams but no one else seems to have to make that sacrafice.... i never considered 15C  will study that now....  The carbon wing spar and gear as well as eliminating the wheel pants will get me 300 grams.  200 dollars on carbon prop and spinner would only get me 65 grams.  All that leaves me with 1.47 lbs to cut and drill out of the airframe not sure i can get that safely.   it must be the airframe is just too heavy....

wagen017

my advice, since you have all the material already, is to build up the plane and go and fly. Most probably the weight will not prohibit you of flying the sportsman schedule.

Then go and compete in your local district in sportsman. I seriously doubt anybody will weigh your plane.

By the time you are able to compete at a level when weight becomes an issue, you will be on your next plane.

In general, the materials you have are all on the heavy side. Put all the bits together is and it is quite overweight. If you go and fly electric you have to choose your components carefully, especially if you don't have a multi$$ plane to begin with. Read as example the old thread on the Fliton Element (which was a great flying airplane despite being a bit overweight).

Volkert

toddblose

My Feedback: (10)

shepga is right don't spend alot of money just come and fly, you will not be turned away at a local contest flying sportsman

Hokie Flyer

Todd's right, weight is only an issue at the NATS anb maybe a district championship.  Fly and have fun.  Worry about weight if and when you plan on competing at the NATS.


Rob

texzen1

Thanks Mr Shepherd...It was both a Houston and Dallas events where i saw the grater than 11 pound planes being alowed to compete....iYour right i think technology will eventually get it there, although i believe the real problem is the rule....which has been 5 kilos since 2 stoke .61 days.....i Fly in Europe also where i work and have run into a mess of top guys over there refusing to compete anymore unless the rules are changed. Some say any weight limits should be minimums not maximums or at least the nitros should have to be weight at full flight tanks tanks so they have to stress over ever drop like electrics must do over every watt.....

wagen017

again, don't care about the rule and go enjoy pattern flying.

Which part of Europe?

Volkert

texzen1

Volkert....In England (Manchester Area) and a few times in Copenhagen where i have to borrow my buddies practice plane which i hate doing...

toddblose

My Feedback: (10)

Just have fun and show up at some contest... It will be fine

petec

My Feedback: (58)

That is great advice.

wagen017

I think you should be OK. You got any other guys flying pattern close by? Check with them then.

I have understood they only weigh at European championships. You might need some practice before that...

Volkert

Jetdesign

My Feedback: (8)

One more vote for just saying "just go fly". Pattern is tons of fun and you won't get weighed at local events.

You are getting into electric, which is great. When you decide you're ready for higher level competition (i.e. NATS), you can start piecing together a new, lighter plane; you already have most of the components taken care of. While competition-grade equipment is always more expensive regardless of sport or activity, there are more and more options for competitive electric planes under 11lbs. 2M is not a requirement, and if you're going to push the size and weight envelope there will generally be a penalty in price.

I have a hard time seeing the validity of the 'weight issue'. People want the biggest, strongest, lightest planes and don't want them to cost a lot of money. I don't know where else you can get high-tech, custom, competition-grade equipment without paying a fortune. Like anything else, you don't need the biggest and best equipment just to enter competition. If you want to compete with the best in the region/state/country/world, you have to assume you're going to fork out more money for better equipment. I didn't start skiing on $1300 Titanium-infused skis, start riding a 1 Liter motorcycle, or playing a $1000 guitar, but I got to the point in these things where I felt the money was well spent and could truly appreciate the fine technology and craftsmanship. I'm working my way up in pattern flying. I have a 1.10 size plane that competes as well as I can fly. When I feel I can truly benefit from a 2M plane, I'll get there, but right now I certainly don't need it to be competitive - I am pretty convinced that anyone who scores higher than I do with a 2M plane would most likely do the same with my 1.10 Wind.

baronbrian

My Feedback: (13)

Or clubs rule in Minneapolis which I CD'd for many years was 2Mx2M, 11#, AMA# on wing. We always check 2 of these 3. since 1999, we haven't had a scale at the contest.

grotto2

My Feedback: (2)

Joe makes a good point here that our planes don't have to be a full 2m. Weight goes up by volume which is a cube of length or span. Frankly, I'd be just as happy with a plane 2" to 4" smaller that was sturdier and didn't cost a fortune due to exotic materials and manufacturing. Betcha couldn't tell the difference in the air, either. Do the manufacturers make them exactly 2m because the top-end pilots demand it?

Strat2003

My Feedback: (1)

It's pretty common to allow any AMA legal airplane in Sportsman. It's the class for trying out pattern, getting used to flying in front of judges and learning the very basics.
Having said that, you can probably save some weight with lower-capacity batteries. The Sportsman pattern is pretty short compared to Masters, and 5000mAh packs get the Masters guys through it.

lsjpeng

A light motor may save a lot of weight. See pics below.
AXI 5330/F3A ~700 grams
Himax 6330-200 ~620 grams
Plettenberg 30-10 ~590 grams

You may save some more form the prop.
APC 21x14 ~120 grams
Falcon CF 21x14 ~67 grams

As others already mentioned, battery pack may save the most. For example, I used 2900-3200 mAh in the new short Master sequence, so I don't need TP5300 10S (~1170 grams). I'm using TP4350 10S (~1045 grams) now.

Hope this will help

Luke

texzen1

yep all makes a sense now.....i did expect to start out using the top of line stuff....i just didnt know it would take top of the line stuff just to make the weight.....(they usually let you on the ski slopes without titanium skiis.....the AMA rules state minimum 11 pounds and give the beginner and sportsman class a whopping 115 grams leeway.....i need a 1000 gram leeway....  knowing all this i would have gone the 110 route....  but the real grace is i guess the local club events are using AMA as a guideline and not really beating up people about the rules until you start competing in AMA sanctioned events....Although the one i went to in Houston was AMA sanctioned there was no scale to be found.....   i feel better now....was worried i had bought and built a 13 pound fun flyer only....already had a shop full of those....