What is too heavy to fly?

[Mr Crayon]

Hello,
I'm new too building these models, I am part way through my first build, it is a series 300 Beechcraft Muskateer. I have built this entirely from the wood supplied in the kit, and after reading some earlier posts, I thought I may be in trouble with wieght. I have built all the frame and am ready to start covering.

My fuselage is 14.6 grams, I have noticed some of you have MUCH lighter by using replacement balsa, rather than the kit supplied stuff. This is my first model and I really want to make it fly. My wing weights also vary from one wing to the other, I guess that would be glue making the difference? Is that going to ruin it for flying?

How heavy could/should a 20 inch plane be for flight?

(I am absoutely new to this so any tips greatly appreciated)

[dbcisco]

In general, lighter is better. However if you are going electric or gas RC strength needs to be taken into consideration. My SE5 comes in at 10 oz. with battery and 180 motor. I am waiting for a nice day to maiden her. Stall speed is going to be around 15 MPH so landings wil be... tricky (using wire reinforced landing gear because of this).

[Mr Crayon]

For this one I'm intending to use rubber. I will use the kit rubber first then look for better stuff maybe.

I'm already hooked on this hobby and plan to make more models which I will probably use electric motors on and include RC gear down the track, but rubber for now. For some reason I love the idea of a rubber motor giving good flight times.

[scigs30]

I can tell you that if you used the kit wood and kit rubber, that plane will not fly. You can buy some rubber from an online company and use that and you might have a chance. I built the Piper Cub from the same series and replaced all the wood and used aftermarket rubber and it flies great. The 300 series planes are awesome looking but they use way too much wood for free-flight and the wood supplied is way too heavy. My advise is finish this build and cover it. Try to fly it and see how it goes. The next time just use better quality wood and you should be ok.

[thymekiller]

For scale planes to fly really well, a rule of thumb is .5 grams per square inch of main wing area. They will fly if they weigh a little more, just not that far. Your plane will probly fly.
What all the fuss is about is how long will it fly. If this is your first plane, then the extra strengh is not such a bad idea. The thing you want to achieve is steady, repeatable flights. Even short ones. This is done by getting the wings and tail to line up correctly so as to produce the same [mostly ] flight every time. Regardless of air time, trim is more important than weight, in the beggining. A super lightweight plane with poor trim will not fly any better than a brick.
After you build, glide it a few times and try to get a gentle stable landing. Then gradually add 50 turns, then 100 turns ect.
Remember, light weight is not all of it. It is important, but not all of it.

Also, try to match the weight of both main wings, or it might dip to one side. Doesent have to be dead perfect, but very close.

Hollar if ya' need us. Welcome aboard.

thymekiller

[Mr Crayon]

Thanks guys, this is my first model so if it flies, I will be happy, not worried over flights times yet (although I will be). This IS my first model so I am useing it as a learining experience. Hopefully I will work out how to trim it for flight and my next model (I'm thinking 600 seried Cessna, well I've already ordered it so yes 600 Cessna) will be much better.

Is it with rubber just not enough thrust for this one? What weight is too much? And also can I use the rudder to 'trim out' the weight difference in the wings?

Also, I really wanted to say thanks to all the tips you guys give, I have read over a lot of the previous posts, and without this forum, as a new builder, I would be without a chance. Some of the builds posted here are amazing and give me something to aspaire to.

[thymekiller]

Scrigs30 is a FAR better source of info than me. I have not built that plane.
If there is a big differance in the weight of the two wings, I dont think you can trim that out. You will need to make the heavy wing weigh less.

There are several ways to find the wing area on a plane. In order to fly, it needs to weigh about a half a gram per square inch of wing area. Do you have scales? I have taken my planes to the post office to have them weighed. Off hand , I do not know the wing area of that plane. Maybe someone else on this site can give you a good target weight.

Go ahead and build it and try it. Even if the flights arnt quite as much as you hoped, the gain in overall knowledge is worth it. One thing that troubles first time builders is gathering up the supplies and tools nessary to complete a build. If that first plane never flyies, it will prepare you for the next one, both in tools, work habits, and confidence. Besides, its GREAT fun. Bigtime race drivers dont start out at the indy 500. Those big long flights are generally done by guys who have several builds under their belt. I have built many planes just for the fun of chopping balsa. Still do sometimes.

Scrigs it correct about the rubber in the kit. Good rubber is cheap. I recommend 1/8 . A quarter pound is a HUGE amount of rubber. 16 feet of the stuff will give you a great chance to try it out. Try this link:

http://www.peck-polymers.com/store/Category.asp?Cguid={8CFA840F-849E-4130-A4C5-7A71F4B6EE5E}&Category=ModelSupplies%3ARubber

thymekiller

[scigs30]

For the 300 series I normally shoot for 30 grams excluding clay and rubber. There is no way to achieve that using kit wood, but that's ok. I learned to build on Guillows kits because they are so cheap. So go ahead and build away and complete every project 100 percent. By doing this you will get better at building free-flight much quicker than if you build part way, stop and start another build. You have to go through the growing pains of building and covering. As far as this build, don't add landing gear and that might help. Don't worry about 1 wing being heavier than the other this has never been and issue for me. Also is there a reason you want to build Guillows kits? These are not the best kits for flying. If you are heart set on Guillows that's ok, you will just have to learn to do some modifications to get them to fly nicely. We can help you with that.

[earlhouse]

If it is too heavy to fly, just paint it up nice, use a ruling pen to add the control surface and other scale detail lines. Carve a scale propeller to match the details on the plan and hang it up. I have many of these built years ago that were stored in the attic. I have been taking them down and recovering and painting and detailing for static display models. I don't trust the old glue joints for flying. The acrylic paints from Wal-Mart work great for painting these. I have found that Windex makes a very good thinner for these Acrylic paints to use in an airbrush.

[KySteve]

For the 300 series I normally shoot for 30 grams excluding clay and rubber. There is no way to achieve that using kit wood, but that's ok. I learned to build on Guillows kits because they are so cheap. So go ahead and build away and complete every project 100 percent. By doing this you will get better at building free-flight much quicker than if you build part way, stop and start another build. You have to go through the growing pains of building and covering. As far as this build, don't add landing gear and that might help. Don't worry about 1 wing being heavier than the other this has never been and issue for me. Also is there a reason you want to build Guillows kits? These are not the best kits for flying. If you are heart set on Guillows that's ok, you will just have to learn to do some modifications to get them to fly nicely. We can help you with that.

scigs-What are the best models for flying? I bought Guillow's because that's the only name I had heard. Can you also tell me if the other ones are easier/harder to build? What about price. Thanks

[Mr Crayon]

Thanks for the advice. I will finish this build without landing gear and will try to even up the wing wieghts an see how it goes.
I'll get some rubber and the next build I will use better wood than is supplied in the kit.

The reason I'm doing a Guillows kit is just that this is what the hobby shop had, this is the only brand I've seen. What kind of modifications do you typically make to get these models to fly?

[scigs30]

If you like Guillows, then any of the 600, 700,900 and Fly Boy are great kits and you shouldn't have to switch out the wood. The 500 series WWII are ok and will fly if you do some modifications. If you search my user-name on this forum you will find some of the 500 series I built and the mods I made to make them fly. For most of those kits I used the wood that came with it. If the wood was too heavy I called Guillows and they sent out lighter wood. Great costumer service. As far as modifications:
1. The bigger birds like the 300 series must be built lighter. I like the Guillows design and all the wood they use so I use quality balsa and keep the structure the same. If you choose to use Guillows wood then you can omit some of the structure. You don't need all those ribs, you can shave the inside of the formers to make them thinner, you can replace the trailing edges with thinner wood, the tail surfaces could be laminated basswood or thinner balsa parts. You don't need all those stringers on the wings. To get a competitive Guillows kit you almost have to re design it, that's why most of us build Guillows for nostalgia and not competition flights. For the most part if you don't want to change much, then just use better wood. Also for a better flying model you will have to add a functioning nose block. There is no real way to add down thrust or weight with just a nose button. You can search this forum for different ways of making a nose block. You should also beef up the landing gear. I like to use the sandwich method for my landing gear. A pin stuck in balsa wood then the wheel added will never hold when the bird lands. Also increasing the dihedral will give a more stable flight. Also don't have the rubber motor mount so the hole is up against the front of a former. Try slipping a rubber knot around that set up, not fun. I put the mount where I can easily get the rubber motor around the peg or aluminum tubing I use. Last thing, don't paint the plane if you want it to fly, it is already heavy enough. There are plenty of other companies out there that make kits that will fly great with no modifications such as, Peck Polymers, West Wings, DPC, Dumas, Rockytop models and Dare models. For me, I will stick with Guillows, Sterling and Comet.

[Xanadu]

What a beautiful flight that was!

[Mr Crayon]

Awesome video!

Thanks scigs for all the advice. I'm going to attempt to add a nose block similar to the ones you have shown, still aiming to get this bird in the air, so I will omit the landing gear. All covered now so not too far away from the first test glide, I will let you guys know how it goes.

(expect the worst, I am...)

[scigs30]

Post some pictures...