Scale 20cc Edge 540 Profile “The Glitter”

[BalsaDust]

Basswood is fine. The last 20cc I scratch built I just found a nice straight grained 2x4 and ripped it down on table saw to proper size. Another option which is what I have done on the smaller glitter I built is this. Make the spar out of medium balsa. Rip it down the middle. Glue one half in the spar notches. Then get some carbon fiber tow and lay it on top of it tacking it down at both ends with some CA. Then run a healthy head of Medium ca down the full length and lay the top half of the spar in the notch and clamp it down cleaning up any squeeze out of glue. Also could just clamp in in place without glue and then wick in thin ca from both sides whichever way suits your fancy. Makes an incredibly strong spar but the kicker is there has to be proper glue penetration to bond the carbon and both pieces of wood into one unit. If not there will be a weak spot that will fail over time in flight.

 

[Stevendavis]

Thanks BalsaDust!

 

[Snoopy1]

What material are you guys using for the wing spars? Basswood? Also, where are you getting the glass tubes? Thanks.

I will be using Balsa spars with carbon layers . Someone gave a suppliers name and email address earlier on this site for carbon tube.

 

[Stevendavis]

I will be using Balsa spars with carbon layers . Someone gave a suppliers name and email address earlier on this site for carbon tube.

Balsa, with no carbon?
I just ordered a bunch of wood from Balsa USA and got 3/8" sqr. basswood for the spars. I couldn't find any 5/16 hardwood. I planned on using the 3/8" sqr. spars all the through, with no doubler between ribs 1-4.

 

[Stevendavis]

I see the carbon!

 

[Snoopy1]

What you have to remember is that @BalsaDust is very careful with weight. It is important to be under 7 pounds with 20cc plane. To make it fly the way it should. So what ever you add is ok but it will have an impact on the final weight. I am presently flying a 20cc profile that at 8 lbs and it fly’s heavy compared to 7 pound plane. I sure @BalsaDust can add to this and explain more about target weights.

 

[Stevendavis]

Thanks Snoop,
I'll have to keep that in mind.

 

[BalsaDust]

3/8” spar is fine. I think I only have the doubler drawn out from R1 to R2 and I would still use it. When building a profile just remember not to overthink it. You want it light yet strong and I have learned a lot from the Probro sure on how to achieve just that.

 

[Stevendavis]

3/8” spar is fine. I think I only have the doubler drawn out from R1 to R2 and I would still use it. When building a profile just remember not to overthink it. You want it light yet strong and I have learned a lot from the Probro sure on how to achieve just that.

Thanks! I'm still in the process of finding building materials. A carbon fuse tube should be fine right?

 

[BalsaDust]

Thanks! I'm still in the process of finding building materials. A carbon fuse tube should be fine right?

Yes. A glass tube would be better as it will flex more in a dork but carbon is fine.