Author Topic: Tutor II fuse stiffness question (Read 1072 times)

Jim Oliver · « **on:** October 11, 2006, 08:38:49 PM »

Hi,
I have decided to refinish my Tutor II fuse. I sanded off four ounces of Rustoleum paint.

I want to improve the torsional strength of the fuse without adding back a lot of weight.

I have considered adding 1/16 sheet balsa to the sides of the fuse, with grain at 45* to the fuse length. Also have thought about applying carbon fiber strips to the fuse sides with CA/epoxy. I have some carbon strips that are .014 x .50 inch.

Any structural types with other/better ideas please respond.

Thanks,
Jim

Steve Holt · « **Reply #1 on:** October 11, 2006, 10:25:06 PM »

You might consider sheeting both sides with 1/64" plywood. Minimal weight increase and lots of stiffness.
Steve

Dennis Moritz · « **Reply #2 on:** October 12, 2006, 03:24:50 AM »

What happened to silkspan and dope. Carbon fiber's more tricky. The ply and epoxy would stiffen things up big time and also add weight. Also handle the issue of stray patches of rustoleum that might have been missed. Is it time for another ARF Tudor? Can peal off the kote and do it your way. Perhaps strengthen the front end, if needed. A friend did that with a Cardinal ARF. Helped the plane some.

Bob Zambelli · « **Reply #3 on:** October 12, 2006, 07:26:08 AM »

Steve, Jim, Dennis - we faced a similar problem with the ARF/ARC Cardinal.

I directed the factory to laminate the fuselage sides with .5 MM plywood.

As mentioned, no noticeable weight penalty, great increase in torsional rigidity.

Dope and silkspan will help bit it's still compliant. We did not try the carbon fiber.

Bob Z.

Jim Oliver · « **Reply #4 on:** October 12, 2006, 10:42:46 AM »

Bob,
I have added 1/16 sheet at the 45* angle to both my Cardinals (needed tail weight anyway for the ST 51).
The increase in stiffness/torsional strength was easy to "feel" and "see". I just sheeted over the fuse cut-outs--also included a tail weight box.

The Tutor is at or very near the bottom of my list of models, ARF or otherwise, to own again. On the other hand, I have two Cardinals flying with two more for back-up (in the box).

I'm just trying to get this Tutor good enough for me to try to learn the "Big Boy" pattern with.

Thanks for the info.

Jim

Steve Helmick · « **Reply #5 on:** October 12, 2006, 10:49:22 PM »

If the fuselage is all sheeted or solid, I'd cover it with either .75oz/yard fiberglass cloth, or .5 oz CF mat with epoxy thinned to watery consistency with shellac thinner (alcohol). If the fuselage has cutouts like the Profile Cardinal ARF/ARC, I'd cover it with silkspan, give it a few coats of clear dope, then cover with the .75 oz fiberglass.

I once built a quicky F1A from some ribs Tom Hutchinson gave me, using an old fuselage and circle towhook. It needed some torsional stiffening, and the glass over Japanese tissue did a fine job, applied with clear dope.

Steve

Author Topic: Tutor II fuse stiffness question (Read 1072 times)

Jim Oliver

Tutor II fuse stiffness question

Steve Holt

Re: Tutor II fuse stiffness question

Dennis Moritz

Re: Tutor II fuse stiffness question

Bob Zambelli

Re: Tutor II fuse stiffness question

Jim Oliver

Re: Tutor II fuse stiffness question

Steve Helmick

Re: Tutor II fuse stiffness question