George , Nice work. Your inovation and thoughts make life easier. i can't wait to see some video when it happens. What are you bonding the Mylar to the airframe with?
Thanks for the contributions,
**Neons** Bob

Originally Posted by Tsavah

I am assuming you used a super glue for assembly, but I'm not sure what the disks are made from. My first thought was an old 5.25 floppy diskette cover/envelope/jacket. Interesting project and a heck of a lot of carbon fiber. Using thicker Mylar makes sense. Not sure about a good source for the old Efite Beast electronics. What do you recommend?

Yes, the disks are slid under the joints and medium CA is applied to the joint. The disks are made by waxing a glass plate with mold release and then coating the glass with epoxy (I use West System it flows well). Then lay a piece of CF veil onto the layer of epoxy and squeegie out as much of the epoxy as you can (keep it light) with a flat, stiff tool (I use a piece of .015 mylar). Be sure to tape down one end of the veil and scrape away from the tape.

After the epoxy cures, lightly sand the side that is exposed with 320 grit. The sanded side will be the side that is placed up against the joint so the CA will have a good surface to adhere to. The side against the waxed glass should be cleaned with acetone to remove any wax residue to insure good adhesion of the contact cement to the disks. Don't forget to sand the entire length of all the CF rods befor assembly for the same reason..

In the pictures you will see a dark 1/8 inch wide strip down the center of the top view and each side of the side views. These are long strips of the epoxied veil that the disks are made from. The 1/2 wide top view strip was slid under the 1 mm center rod so that there was some area to for the mylar to adhere to when covering. This strip also allows for making a few holes for attaching "splices" between the top and bottom of the fuse pieces during assembly. I installed three splices to stiffen the top and bottom pieces to eliminate having to use a lot of side braceing. The veil strip allows support for the mylar when the holes are made.

The larger disks were installed in places I knew I would be making holes for support rods so the mylar would not tear.

As for the "Beast" gear you will have to trash out a Beast which will be cheaper than buying the parts seperatly. E-flite is coming out with a new Beast with stability control and which uses an E-flite 180 motor. Nobody said all of this would be cheap.

Originally Posted by **neons**

George , Nice work. Your inovation and thoughts make life easier. i can't wait to see some video when it happens. What are you bonding the Mylar to the airframe with?
Thanks for the contributions,
**Neons** Bob

Thanks Bob.

I just lay the frame down on a piece of poster board and lightly spray some 3M contact cement over it. I'm sure somebody has a better and lighter way to attach it but for the time being with all the experimenting I'll stick with this method.

Also, I roll the Mylar out on a clean glass surface and tape it down untill all the wrinkles are out ( I don't apply much tension). After the frame is sprayed I just flip it over and set it down on the Mylar and use a roller to go over all the rods to seat them to the Mylar. After cutting around the edges I lightly touch the edges with a Monocote iron set on a low heat. I haven't played around with Mylar much so I always end up with a few wrinles after cutting the piece out.

George

Originally Posted by Lantsov Alexey

Hello all .
Let me introduce my new plane for the F-3-P."RELAX-2"
Span - 910 mm.
Length-1090 mm.
Weight-87 gr.
Propeller - 9x2 (homemade)
Motor 18-3/40 (homemade)
Servo D 47 S
ACC-120 ma

Lantsov,

Oops! Forgot to tell you what a great job you have done with all your building experience with the CF rod airframes. Extremely nice work!

You got me hooked with this type of construction. I don't ever expect to match your low weights (my gear limits me) but you have given me a great way to pass the winter months.

Thanks,

George

Originally Posted by Tsavah

Interesting project and a heck of a lot of carbon fiber.

Tsavah,

Yes, these airframes do consume a lot of CF rods. I don't mind paying $1 US for the 1mm rods but I balk at the cost of $2.50 for the .6mm rods so I make my own .6 mm rods to keep my cost down. My next project will use .025 inch rods in place of the .6mm rods (.030 inch)

George

Tsavah
Your work is wonderfull and you have a super imagination in building and technics. You are an Asset to Modeling

George,
You have added further simplification to the process. I am probably a down and dirty builder of planes. i like simplified ways that work well but not skimpy workmanship. I like your idea of mounting the Mylar. Of course I cannot build very light weight but this will be a reasonable start here. Times have changed in material and availability of new product applications. I remember in the early 50's when the indoor micro light weight rubber planes had Celuloid microfilm covering. It was so much different to get that clear covering on the plane. They used to pour the chemical into a tub of water and when it skinned over they used a hoop to llft it out of the water. Then it was placed very cautiously over a doped airframe and trimmed. Very intense work for a contest rubber micro plane.
**Neons** Bob

Originally Posted by Ampbomber

Hi,

Well, I have been happy with the way I have rid building the CF frame without having to do the tedious "tying" of every joint as posted before.

The most difficult task was covering the frame with mylar (and painting it) after it had been completely assembled so I decided to atempt building the CF plane as I do all my foamies (paint it, install the bottom and then install the top.

I selected Metrorcflying's Relax plans and reduced them to a WS of 25 inches and planned to use the gear from the original Eflite Beast (it has the Eflite 180 brushless motor).

With a few inovations I was able to do the construction as planned. It was so much easier covering and painting the 3 pieces with mylar before assembly.

Here are some pictures of the project. My only regret is that I used 2 u mylar instead of the 5 u mylar I have in stock. The pictures lie a lot about the appearance of the completed plae as I poked quite a few holes in the 2 u mylar during the installation of the gear and had to patch them.

AUW w/battery is 60 gm. Flight will be next week if I can get to the flying site.

George

Well, all did not go well with the test flight. The elevator locked up and a fatal crash followed a few seconds into the flight.

I was not happy with the 2u covering anyway, as stated before, so I spent the week removing the 2u Mylar, fixing the airframe and recovering with 5u Mylar. The results are shown below. Even with the 5u covering and painting the airframe white ( better visibility) the AUW w/battery came out just shy of 60gm. I did modify the battery which saved a gram.

Again, I was happy with the 3 piece airframe covered before assembly. Hopefully the maiden will go better next week.

George

In this thread, I've seen only straight pieces of carbon rod used. I watched a video on YouTube about making landing gear for very small 3D foamy planes. They used carbon rod and heated it with a soldering iron and gently pressed it into a 60 degree bend for the wheel axle. Then they added CA and some heat shrink tubing over the joint to maximize strength and rigidity.

It seemed to me that such a technique could be useful here in many joints. Has anyone done it? Which joints in the plane would make sense to use bent carbon fibre rod instead of just straight pieces?

Thanks in advance.

Jim Marconnet

Originally Posted by Jim_Marconnet

In this thread, I've seen only straight pieces of carbon rod used. I watched a video on YouTube about making landing gear for very small 3D foamy planes. They used carbon rod and heated it with a soldering iron and gently pressed it into a 60 degree bend for the wheel axle. Then they added CA and some heat shrink tubing over the joint to maximize strength and rigidity. It seemed to me that such a technique could be useful here in many joints. Has anyone done it? Which joints in the plane would make sense to use bent carbon fibre rod instead of just straight pieces? Thanks in advance. Jim Marconnet

That Youtube video was interesting, wasn't it? I tend to avoid carbon fiber products as much as possible due to cost, but I have seen some very useful things done with them. One guy was splitting carbon strip so he could form it around a curve and glue the other part back on. He wanted his carbon frame wing to be rounded on the tip, as well as his fuselage. Another was making a butterfly wings frame. Not so long ago folks were using bamboo strips to do the same thing by heating the bamboo with a candle for a sharp bend, or an oven on low temp for a gentle, long curve. Now one can buy fake bamboo blinds I am told is actually "fruit wood" and do the same thing without the joints/knuckles every few inches or so in the case of actual bamboo. In all of the examples, when two pieces of wood, or rod need to be joined, it was common to use a thin walled tube over the ends. The tube could be used in a number of ways to join more than one piece at the joint. Interesting stuff if one is into thin lightweight frames to cover in thin sheet plastic. A popular tubing these days is the heat shrink type.

Originally Posted by Jim_Marconnet

In this thread, I've seen only straight pieces of carbon rod used. I watched a video on YouTube about making landing gear for very small 3D foamy planes. They used carbon rod and heated it with a soldering iron and gently pressed it into a 60 degree bend for the wheel axle. Then they added CA and some heat shrink tubing over the joint to maximize strength and rigidity.

It seemed to me that such a technique could be useful here in many joints. Has anyone done it? Which joints in the plane would make sense to use bent carbon fibre rod instead of just straight pieces?

Thanks in advance.

Jim Marconnet

Jim,

My experience with heating and bending CF rods is more tedious and time consuming than it is worth. After you heat the rod you destroy the epoxy to CF bond which has to be repaired with CA after the bend.

The best way I have found to do curves is to make some very thin CF rods which will follow a curve nicely. Two or three of these thin rods are set together along a pined curve and then thin CA is applied to "lock" the thin rods together. In my previous post you can see that the top part of the plane has a nice curve to it.

George

https://www.rcgroups.com/forums/show...&postcount=109

I spent a lot of time to describe the technology.
Model aircraft of carbon can be beautiful.

Originally Posted by Lantsov Alexey

I spent a lot of time to describe the technology.
Model aircraft of carbon can be beautiful.

Lantsov, that is indeed beautiful! You are an Artist of Carbon Fiber.

Originally Posted by Lantsov Alexey

I spent a lot of time to describe the technology.
Model aircraft of carbon can be beautiful.

Lantsov,

Yes, you have done a fantastic job in describing the technology of building these CF framed aircraft.

The one thing you have to remember is that you have, at your disposal, some things that we cannot achieve with our builds. We can build the airframes but are limited at reaching your weight goals by such parts as the CF tube you use on your builds. Also, your motor and prop combo, made by you, is difficult to reproduce weight wise. Personally I am hampered by the amount of $$ that I can spend so I try and figure ways to cut cost (ie making my own small diameter CF rods). I know you have inspired me to think outside the box.

Have you changed any of your construction techniques? Are you still tying all the joints and covering the completed airframe ?

Any video of your new plane?

Thanks for all your insight.

George

Really nice. Will it be in kit form?