I ordered 4mm carbon rods not realizing that they are differant than tubes. Will my Yak54 suffer from excess wieght or flex? Is there any advantage to the rods such as durability?

The rods will work, but it will be heavier... As far as strength goes, it will be stronger, but not in a useful way... the plane is light enough that the extra strength is not a benifit, just heavier.
You can always install them temp. with packing tape to get the final weight... if it is unacceptable, then remove and purchase the tubes.

Good luck.....

Levi Jordan
www.3DFoamy.com

I know for other materials like aluminum and steel, a tube is many times stronger than a rod due to how the pressures are evenly distributed the walls of the tube. Maybe in this small of a scale, the rod is stronger than the tube but I doubt it. I'm with Levi, try it out and see if you think it'll be stiff enough.

tmproff,
You mean less flexable up untill the point of failure, at that point I would have to say rods would be stronger. The point is moot for the application we are talking about as I have not heard of anyones foamie wing folding in flight.

Since I already have several rods and they weigh less than an ounce for a 4' peice I am going to give them a try and not worry about the weight. Does anyone know the weight of the tubes?

The rods will work. They will flex more than the tubes and weight more, but you wont break them.
The carbon tubes weight 10.7 oz. for a .157 dia. 36" long tube.

Roger.

Roger,
You mean 10.7 GRAMS don't you?

Yes, grams!!! Sorry.

Roger.