stunthanger.com
Building Tips and technical articles. => Building techniques => Topic started by: David Ruff on September 07, 2016, 05:34:01 PM
-
Any merit in drilling some lightening holes in the fuselage and elevator?
Seems as if the fuselage has plenty of wood.
Obviously the areas would be covered with silkspan or film.
Thoughts...
-
no, its already twisty enough, drilling holes will make it worse, the Cardinal profile is notorious ( at leaast in my experience) for being twisty ish in the tail
-
Thanks, Mark. Interesting as it looks like the rear half of the fuselage is rather beefy.
-
How about drilling (hole saw) lots of big holes and sheeting with 1/64 ply?
-
Why not use the same construction as the Kingfisher in the May-June Stunt News?
-
Dave,
The problem with lighting holes is they don't save that much weight if the wood is normal 4-6 lbs stock and you give up stiffness. It also can mess up the CG and require adding tail weight. If you do some holes then sheet the sides (before shaping) with 1/64" ply you will just about break even on the weight and gain a lot of stiff. If you go this route, use slow cure (say 2 hr) epoxy, applied to the plywood, use a playing card to scrap off the excess epoxy (you only need to just see the surface damp not covered in epoxy). Use an ACE bandage to wrap the fuse/ply or heavy weights along its length. When you install the stab use 3/8" fillets top and bottom to add stiffness to the stab (I would add 1/2 oz glass cloth over the stab or carbon vail). Good luck.
Best, DennisT
-
The ARF Cardinal profile did have a hollow fuselage, didn't help it.
MM
-
Mine is an ARC kit from 2005/6 and has big cutouts in the rear part of the fuselage. The stab and elevators are built up as well. Result being a very light model, 45 oz ready to fly with a 9.5oz battery on board.
The thing flies like its on rails, there is some twistiness but it's not evident in flight.
-
Mine is an ARC kit from 2005/6 and has big cutouts in the rear part of the fuselage. The stab and elevators are built up as well. Result being a very light model, 45 oz ready to fly with a 9.5oz battery on board.
The thing flies like its on rails, there is some twistiness but it's not evident in flight.
45 ounces isn't that light, but it probably doesn't need to be that light, either. It is generally a very bad idea to take out any material from the aft fuselage just to save 1/4-1/2 ounce.
Brett