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

Posted: 21 Nov 2019, 11:00
by norm
Elevator Control Sys

The elevator control system of the original Mita is a linkage half by rods and the rest by wire. There are two bell cranks, one at the middle and the other at the end of the fuselage. Two rods connect the pilot sticks and the foward bell crank. Between the bell cranks there is a wire linkage and the elevator is connected to the aft bell crank by a connecting rod.

My 1/3 scale model simulates this system. A servo is placed under the aft pilot seat and connected to the linkage rod. Thus the control sticks moves for and aft in accordance with the elevator up and down.

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

Posted: 23 Nov 2019, 01:22
by norm
Vertical Tail
The vertical tail of the Mita has similar structure with the horizontal one, planked fin and non-planked rudder with oblieque ribs. In the 1/3 model, these are all made of balsa except the fin spar which is made of cypress. The rudder has two hinges, mid and bottom, and it can be put on/off the fin easily. Both the fin and the rudder were assembled on jigs made of balsa.

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

Posted: 24 Nov 2019, 06:24
by norm
Rudder Control Sys
The rudder control system has a conventional wire linkage. There are four turnbuckles, two in between the front and aft pedals and two in between the aft pedals and the rudder. I made these turnbuckles from 5 mm dia bruss rod. The pedals are made of bruss tubes. The rudder servo is placed just after the front pedals and is linked with them. It works as the pilot feet. Behind the servo there is an instrument panel, so the servo can't seen from outside.

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

Posted: 24 Nov 2019, 17:23
by MDev
I like the thinking behind this fuse structure, I’ve made a tail out of Airex and carbon sandwich glued with epoxy and sailing masts out of carbon tubes With jumper struts in a similar fashion, they’re holding together still after 15 years or so. I wonder how resilient the structure is and do landing forces pass through it to the built up wings? Time will tell.

M

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

Posted: 25 Nov 2019, 03:53
by norm
Cliff, yes it is a pity for me too that I can't show you my model and fly it over the beautiful scenary of the U.K.
I have been in the U.K. several times and love the scenary of the Cotswalds best. How I hope my model flying over the gentle hills there!

norm

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

Posted: 25 Nov 2019, 04:27
by norm
MDev, thank you for your comment. It is interesting that there are many modelers who have interest in my carbon truss structure. I glued it with carbon filaments mixed epoxy and attatched a small carbon plate where the stress seems high.
Yes the landing loads may be the most severe one but they make compression at the truss joints. Epoxy glued joints are week for the bending or tension stress but they endure for compression stress much better. So far they look working well but, as you say, time will tell the truth.

norm

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

Posted: 25 Nov 2019, 07:22
by norm
Aileron
The ailerons of the Mita are the frise type one. They also have a differential too. It was very time consuming task to design the rib contour because the base wing airfoils are defined parallel to the air flow, but the aileron ribs are placed diagonally to the wing span. If I could use the 3D CAD it would be easy task but because my CAD is 2D, it took time.

The ailerons have mass balances. I made them with aluminum tube and block. The real Mita's ailerons are linked with the sticks but in my model ailerons are linked with the servos placed in the wing, so the sticks are free laterally. I used a small dummy servo connected to the stick longitudinal shaft. It prevents the sticks from lateral free movement and moves them when the ailerons are moved.

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

Posted: 25 Nov 2019, 09:00
by Peter Balcombe
Norm,
Amazing attention to detail and very good engineering skills.
Very well done indeed.
Peter

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

Posted: 26 Nov 2019, 04:56
by norm
Peter, Thank you for visiting my thread. I will post more details and hope you will enjoy them.

norm

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

Posted: 26 Nov 2019, 05:41
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.