Magician II modifications(it's finished)

O.K. here are the modifications I made to the Magician. I had what I thought were good reasons for each though you may disagree. Almost all the mods have or had some connection to this forum or my experience (what little that may be).

Fuselage: replaced wood, a bit lighter and straighter. I lengthened the motor mounts back almost to the leading edge. I inset a spruce block through which to anchor the landing gear. A 2 inch wide “C” plate was recessed and attached to the motor mounts to improve strength and ease for different engine mountings. I added a 1/4 inch inboard cheek trippler. The outboard side was left flat to aid in wing & stabilizer alignment. Only the inboard side was tapered and shaped. I also added a tail weight box.

Wing: I simplified the wing a bit. 3/4 x 3/8 leading edge. 1/8 x 3/8 trailing edge. Both were slotted dado style for easy rib fit and better joints. “D” tube and cap strip with cross bracing between the top and bottom spars. I made open frame wing tips (about half the weight of the kit tips). added adjustable slider leadout guide. Used ballpoint pen style tip weight holder (allows the weight to be moved for or aft of the CG). I used 1/8 in. ply bellcrank mounts attached to the top and bottom spars, the bellcrank was suspended between them on an aluminum screen door stand off pin( very nice, flat heads, screw together, very light and strong.) The wing panels are equal in length as are the flaps. The flaps are 1/4 in tapered to 1/8 in with 1/32 ply re-enforcement over the horn area. The center section sheeting has a 1 in wide fiberglass cloth re-enforcement were the fuse meets the wing for added strength.

Stabilizer and elevator: stabilizer is 1/4 in built up (1/16 sheet top & bottom over 1/8 in frame). The elevator is also built up but tapers from 1/4 in to 1/8 in with 1/32 ply re-enforcement over the horn area.

Vertical Stabilizer: 1/4” light balsa sanded to airfoil shape with 1/64 ply on the outboard side. The ply adds strength and split resistance in the event of an inverted landing. No offset or rudder.

Control system: the 4” reverse bellcrank was drilled with lightening holes and beveled to reduce weight(saved several grams). As mentioned it was suspended on an aluminum screen door pin with 1/4” I.D. nylon tube spacers. Copper tube covered leadout connections at the bellcrank. I used CF arrow shaft pushrods for both the flap and elevator. I made a custom aluminum flap horn with ~9 degrees offset with dual ball links.

Numbers: The nose moment is the same however I moved the stabilizer /elevator back 2 inches. 0 degrees engine offset. 0 degree wing incidence, 1/2 degree pos.stabilizer incidence, 0 degree rudder offset.

Landing gear: SSW aluminum gear, re-cut and drilled with lightening holes. Dave Brown light wheels.

That’s all that come to mind right now. I hope it’s helpful in some way. If anyone has questions or wants a longer explanation let me know, I’m happy to reply. Thanks again for your interest.

DINO,
Thanks for taking the time to post all the pictures, really nice of you. Great Plane. Let us know how it flys

Like Greg I am greatful for your posting and the time you have obviousely put into it. I would like to see some more details of your wing jig method. It looks pretty simple, but I am not quite sure how it works. Please post more sir! (in my best Tiny Tim voice)

Looks really good. What aluminum did you use for the horn? Reason I ask is that I have had pieces of ordinary hardware store 1/16 in. aluminum fatigue and break from vibration. You might keep a close eye on the bend. With that pushrod setup you'll probably keeps some elevator control though, so a cracked horn wouldn't be totally catastrophic.

The horn is cut from a piece of 1/16 aluminum "angle iron" so I am not creating a bend to stress(of course this dosn't mean it won't fatigue) I used a dubro horn as a rough pattern, in fact the mounting holes are the same so I can use the dubro nylon screw back plate. I have used this set up on my Starion 35 with no problems. the reason I went to it was that I noticed some small twist & bend of the nylon horn under load. I can't swear this was a problem but I didn't like and I feel better knowing that the controls are constant. Thanks for the advise; your right, it's always agood idea to keep an eye on things.

harmonic vibrations appear to be what fatigue aluminum the fastest. if you see it vibrating along with the engine it probably won't last. The part I had a problem with was a needle valve mount. You could see it hum at particular frequencies and it didn't last long.

The ball point pen wing tip weight holder is *clever*, as in "Why didn't I think of that?!" There must be any number of small containers with secure lids that can be sneaked into the wing tip like that. Even just a piece of aluminum tubing with some sort of closure. You could even retrofit a model that needs a wing tip weight box (can you say ARF Nobler or Flite Streak?). Also tail weight, even on profile models.

This is how model airplanes should be built. Careful attention to detail for all critical systems, and beautifully integrated. Nice job!