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1/3 scale Japanese vintage glider Mita type 3

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norm
Posts: 50
Joined: 14 Nov 2019, 10:15
Location: Utsunomiya,Japan
Contact:

Re: 1/3 scale Japanese vintage glider Mita type 3

Post by norm »

FWD Fuselage
As many guests have interest in my model's fuselage construction, I will post its details in order. This time topic is the FWD fuselage.

Mita's FWD fuselage is made by several truss panels. These panels are flat but they are assembled with angles each other.
So, an assembling jig is required. I made the jig using wood bars and plates. This jig is also useful to construct the landing gear support structure and to joint the FWD and AFT fuselages. Be careful that attached photos show the structure before epoxy glueing.
Attachments
FWD Fuselage Plan
FWD Fuselage Plan
Making a panel
Making a panel
Side panels Completed
Side panels Completed
Fuselage Assembling Jig
Fuselage Assembling Jig
Assembling Fuselage on the Jig
Assembling Fuselage on the Jig
Making the Landing Gear Support
Making the Landing Gear Support
Completed Structure
Completed Structure
Landing Gear Fit Test
Landing Gear Fit Test
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VinceC
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Joined: 22 Feb 2015, 11:45
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Re: 1/3 scale Japanese vintage glider Mita type 3

Post by VinceC »

Incredible research and attention to detail. Excellent work

Jolly Roger
Posts: 419
Joined: 30 May 2015, 20:35
Location: Sutton Bank, North Yorkshire

Re: 1/3 scale Japanese vintage glider Mita type 3

Post by Jolly Roger »

You have made some very beautiful and elegant structures. I can imagine the fuselage must feel very light and stiff.

If the joints between carbon tubes are strong enough to take the model flying and landing loads, I think many people will be interested in trying this method. Carbon tube can be bought cheaply on eBay and from HobbyKing.

I would like to hear more about how you glue and reinforce each join, for example, do you make your own carbon powder? And do you insert any material inside the tubes at the joint?

Thank you again.

Roger

norm
Posts: 50
Joined: 14 Nov 2019, 10:15
Location: Utsunomiya,Japan
Contact:

Re: 1/3 scale Japanese vintage glider Mita type 3

Post by norm »

VinceC and Jolly Roger, Thank you for your comments.

Jolly, I used the carbon powder available from retailer and mixed it with epoxy glue. Although it is named "powder", it contains small carbon fibers and if you mix it with epoxy glue it becomes CFRP. It is very tough and light. Weight of the completed basic fuselage I posted yesterday is only 710g nevertheless its length is over 2m. It is very rigid too.

Carbon pipes are jointed with a short piano wire inserted and glued by epoxy where possible, but most joints are just epoxy bonded only. Those joints that seem to be important are bonded with a small carbon plate for reinforcement. The wing support beams are tied up with the longerones by carbon threads and glued. Please see attatched pictures.
Attachments
Carbon Powder
Carbon Powder
Bonded joint close-up
Bonded joint close-up
Joints with small carbon plate
Joints with small carbon plate
Tied up wing support beam
Tied up wing support beam
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norm
Posts: 50
Joined: 14 Nov 2019, 10:15
Location: Utsunomiya,Japan
Contact:

Re: 1/3 scale Japanese vintage glider Mita type 3

Post by norm »

Tail Wing Mounting brackets, Tail Skid and the Elevator Bell crank
The horizontal stabilizer is mounted with three M3 bolts through carbon pipes placed on the AFT fuselage. The vertical stabilizer is mounted at the end of the fuselage with two M3 bolts.

The real Mita's tail skid is made of three ply of steel plates with an abrasive shoe. In my model it is made of carbon plates with an alminum shoe. These plates are not bonded each other for the maximum spring effect.

A bell crank made of carbon plate/pipe is equipped under the horizontal stabilizer which is connected with the elevator.
Attachments
Tail Parts Installation DWG
Tail Parts Installation DWG
Tail wings mounting brackets
Tail wings mounting brackets
Tail wings Installed
Tail wings Installed
Tail Skid and Bell Crank
Tail Skid and Bell Crank
Skid and Bell Crank Installed
Skid and Bell Crank Installed
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Peter Balcombe
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Joined: 18 Mar 2015, 10:13
Location: Clevedon, North Somerset, U.K.

Re: 1/3 scale Japanese vintage glider Mita type 3

Post by Peter Balcombe »

Norm,
How did you cut the bellcrank plates?
Are they all made by hand, or do you have CNC cutting facilities?
Very good work anyway :)

norm
Posts: 50
Joined: 14 Nov 2019, 10:15
Location: Utsunomiya,Japan
Contact:

Re: 1/3 scale Japanese vintage glider Mita type 3

Post by norm »

Peter, I cut them by hand with a mini router which has a diamond saw. Then they were trimmed by a diamond file.
Attachments
Mini router
Mini router
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norm
Posts: 50
Joined: 14 Nov 2019, 10:15
Location: Utsunomiya,Japan
Contact:

Re: 1/3 scale Japanese vintage glider Mita type 3

Post by norm »

Fuselage sub structures
The Mita's fuselage has sub structures around its rectangular main structure, the lower sub-structure, the upper sub-structure and the side beams. With these sub structures its cross section forms octagon when coverd with fabric. Both the upper and lower sub-structures are made of carbon pipes and the side beams are made of paulownia plates.
Attachments
Making lower sub-structure
Making lower sub-structure
Lower sub-structurer
Lower sub-structurer
Upper sub-structure
Upper sub-structure
Side beams added
Side beams added
Side beam
Side beam
Fuselage cross sections
Fuselage cross sections
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norm
Posts: 50
Joined: 14 Nov 2019, 10:15
Location: Utsunomiya,Japan
Contact:

Re: 1/3 scale Japanese vintage glider Mita type 3

Post by norm »

Motor mount
This time I will show you the motor mount.

Why Motor? This may be a common question of the European scale glider fans. First of all I must explain the Japanese scale soaring enviroment. Japan consists of innumerable islands, lage and small, of which four islands are relatively large and most people live there. Total area of Japan is about 370 thosands square km. It is a little bit larger than Germany but, in contrast to Germany, its 70% area is mountainous and 2/3 are covered with forests. On these islads there live more than 120 million people. So there remain little spaces for model glider flying. Because of these enviroments, it is not common to use a tag or a winch that requires somehow a large space. It is common to install a motor and a foldable prop. By the way, because of limitted space, 1/5 scale models are called big and 1/3 scales are extra-big in Japan.

The motor mount of my model extends forward from the main fuselage and requires a special jig to build it correctly. The motor is mounted on a plate made of 9 mm thickness plywood. This plate is supported by carbon pipes and plates. A plywood plate is bonded on the upper side on which the ESC and a battery for the receiver will be installed later. The motor is FUTABA FMA-5065 KV300, 2000W class motor.
Attachments
Motor mount Plan
Motor mount Plan
The Jig
The Jig
Making Mount
Making Mount
Completed Mount
Completed Mount
Mount with the Motor
Mount with the Motor
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norm
Posts: 50
Joined: 14 Nov 2019, 10:15
Location: Utsunomiya,Japan
Contact:

Re: 1/3 scale Japanese vintage glider Mita type 3

Post by norm »

Tow Release
There are two tow release equipments in the original Mita, for the aerotow and for the winchtow. The former is at nose and the latter is in front of the landing gear. I have no tag nor winch but I made these equipments for the model. They are not dummy but really work. These are hand made with aluminum plate. One servo actuates both. As the elevator control tubes pass through the center of fuselage, the winch tow release is attached on the port.
Attachments
Winch Tow Release plan
Winch Tow Release plan
Aero Tow Release Plan
Aero Tow Release Plan
Winch Tow Release Parts
Winch Tow Release Parts
Winch Tow Release ASSY
Winch Tow Release ASSY
Aero TOw Release ASSY
Aero TOw Release ASSY
Winch Tow Release Instalation
Winch Tow Release Instalation
Aero Tow Release Instalation
Aero Tow Release Instalation
Winch Tow Release Test
Winch Tow Release Test
Aero Tow Release Test
Aero Tow Release Test
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