20 Dec 2009: 90 Percent Complete

Things are progressing faster than expected. Maybe due to back to back public holiday on every friday for four consecutive week. WOW!!!

9 Dec 2009: Wing Covering & Test Fitting

7 Dec 2009: Stabilizer Test Fit

5 December 2009: Aft & Fore Section

30 Nov 2009: Engine Nacelle and Aft Section

Twin Engine Dornier DO-28 Skyservant RC Airplane

This is my first attempt to build twin engine RC airplane. As my previous RC plane that I scratch built (L-4 Piper Cub and Jodel look alike), I prefer scale like RC plane, it looks great in the air.

My proposed twin engine RC airplane is as follow:

Model :Dornier DO-28 Skyservant
Wing Span : 96 inches
Wing Chord : 12 inches
Length : 73 inches
Power : JBA46-ABC x 2 units
Materials : Styrofoam, Balsa and Plywood,regular packing tape as covering
Estimated Building Time : 20 hrs ....it could take me 4 months to complete ???

Jodel D -Giant Scale Low Wing Trainer

Specifications

Wing Span 80"

Length 70"

Wing Chord - Wing tip 7 ", Wing Root 14"

Wing Planform - Flat bottom

Diehedral - Polyhydral at 50% wing length, about 3" at wing tip

Engine : OS LA46

Construction Materials: Wing -Foam with 1" x 2/8" wood as spar, Fuse - Foam , Stabilizer - Balsa

Covering: OPP Tape

Landing Gear : Tail dragger, 0.5mm music wire for main landing gear, tail wheel- 1/2"

Dry Weight : 3 kg

Plan: Own design. Wing look alike Jodel airplane(French home built light airplane in the 1950's)

Flight Review
The airplane was maiden on 15 May 2009. As today she had 6 sorties. Airborne at about 10ft with half throttle. Fly slow and easy. The wing's polyhydral really reduce stall rate and add control for slow maneuver. If you are going for some scale like flying, then this is an airplane suitable for you. The construction is not intended for aerobatic maneuver.

Piper L4-Giant Scale High Wing Trainer

Photo taken about 18 months after her maiden flight. Still survive after a crash on take off. TT46 is enough for power, but .60 size engine is better. With TT46 its flies scale like and you need to add 500g lead in front for proper CG. Anyway I really enjoy this plane so far. It can fit into my Honda City plus my family of 5 including my wife for a trip to the flying field in Padang Tembak, Kota Bharu, Malaysia. My next project will be 88" fleet biplane with 26cc weed wacker engine for power.

Preparing For Maiden Flight

At Padang Tembak Flying Field

Fuselage Construction-49 Inches

Few photos during fuselage construction. All parts are made of 3mm plywood, except the stabilizers are laminated with 3mm balsawood













29 January 2006

L4 Piper Cub Fuselage Dimension

Length from firewall to rudder base 43 inches
Width at firewall 5.5 inches
Width at the cockpit 6.0inches


I have five days Chinese New Year Holiday. It was really a good time to start building my Giant Scale L4 Piper Cub.

Materials
My original idea was to built L4 fuselage from a foam. But after looking around in my storeroom I didn't have any foam supply left. Again cost cutting play the role here. I need to buy new foam. No..no.., then I saw 3mm playwood sitting around, a left over of my abandoned quarter scale J3 Piper Cub. Then I thought why not I tried to built the L4 fuselage from the 3mm plywood.

Weight Problem
3mm plywood is heavy compare to balsa sheet. Well I have no choice but to cut a lot of hole in order to lightening the L4 fuse.

Tools
Normal hobby knife with a lot of "hand's power". It really made my thumb and point fingers numb. Well, at least it was good exercises for my hand.

Glue
Combination of Dunlop Contact Adhesive and a little bit of 5 minute epoxy. The secret of using Contact Adhesive(CA) is to apply on both surfaces, wait until it dries (abount 5 to 10 minutes) and joint it together. Never,never apply too much CA, or it may result in weak bonding.


Covering

At the moment I am thinking of covering the L4 Piper Cub with regular white cotton fabric and then to apply automotive paint. I had made an experiment yesterday evening to test wheather nitro fuel will affect the autopaint. It seems that autopaint did not get affected by nitro. I think I will go ahead with the techniques.

Wing Construction (88 Inches wingspan)

27 January 2006


Today I started to built the wing. The main objective is to built strong and reliable, flat bottom wing as cheap as possible with basic tools that I can afford and able to handle.

Putting cost cutting and my limited worksmanship as my main consideration I choose white foam for my wing construction. Wing chord is 12 inches.

Spars were made from two pieces of yardstick. I used 5 minutes epoxy to attach the spars into the foam wing.

As I cannot afford to buy or built hot wire I choose to use regular hobby knife to cut the foam into the aerofoil shape. Later I use sand paper to smooth the surfaces.

Covering was made from regular clear salotape. I plan to paint the wing with dark green color with the invasion strip for visiblity purposes.

Costing

• Foam RM 8.00 (USD2.0)
  

• Yardstick RM14.00(USD3.50)

• Salotape RM 3.60(USD0.75)

• 5 Minutes Epoxy RM 6.90(USD1.60)
• Spray Can Auto Paint RM16.90(USD4.25)
  

• Total RM49.40(USD12.45) !!!!
  

The results
I think the result is not bad. The construction photos tell everything.


My Other blog

www.modelkapalterbang.blogspot.com

Giant Scale Model Airplane with 46 Size Engine

The Idea
This evening I was thinking of making a new project using TT46 engine as a power plant. I met with my friend at the flying field last friday planning to sell his TT46 that he installed at his Stearman. I think I am going to trade my Jumper 25, high wing trainer with that TT46. I will call him tommorow. I hope I have a good luck.

Can the Idea Work???
Normally, giant scale model airplane will use bigger power plant, size 61 and above. Can size 46 fly the plane? I don't know, I think it can fly, if I can keep the weight to the minimum.Wish me luck.


The Plane
The proposed specification for this airplane should be high wing, 90" to 120 "wingspan, length around 70", with weight around 5kg. The L4 cub would be nice. uhup... Control are throttle, elevator and rudder. No aileron? I guess to keep the cost and weight down. Covering, clear tape, again to keep the cost down.

The Materials
I plan to construct the wing from foam, with a yardstick as a spar. Fuse should be from the same materials, except the firewall and the cockpit from balsa or plywood. All flying surfaces will be from foam too.

Time Line
I plan to start the project asap, and should be completed within 6 months, i.e June 2006. Wish me luck please !!!

My other Model Airplane Blog

In Bahasa Melayu/Indonesia

www.modelkapalterbang.blogspot.com