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1/3 scale Japanese vintage glider Mita type 3

Let us all watch your new project progress.
norm

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

Post by norm »

Cliff, RobbieB and StephenB, Don't worry! It happens for me too. Norm
norm

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

Post by norm »

Tail cowling
The bottom of the leading edge of the Mita's vertical fin is cut off for mounting the horizontal tail. This area is covered with a plastic cowling. I made the cowling with PVC. But because I have no experience nor the apparatus to form the PVC, I asked a person who has both. He made the cowling with a wooden form I provided.
Attachments
Tail cowling DWG
Tail cowling DWG
Wooden Form
Wooden Form
PVC formed
PVC formed
Cowling trimmed
Cowling trimmed
Fit check
Fit check
User avatar
chris williams
Posts: 1549
Joined: 10 Mar 2015, 10:50
Location: Blandford Dorset

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

Post by chris williams »

Beautiful work, Norm...thanks for sharing
norm

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

Post by norm »

Covering & Painting
The wing and the tails were coverd with the ORATEX while the fuselage was coverd with the SIG KOVERALL. After beeing coverd they were painted with white acrylic paint spray.
Attachments
Wing covered and painted
Wing covered and painted
Tails covered and painted
Tails covered and painted
The SIG KOVERALL
The SIG KOVERALL
Fuselage covered and painted
Fuselage covered and painted
norm

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

Post by norm »

Completion of the canopy
The canopy transparency was made of PVC. I asked my friend who had made the PVC tail cowling to make it. He also made the canopy wooden mold with the plan I provided to him. After receiving the transparency I trimmed it and attatched it to the frame I had already made. With the canopy the model Mita became very realistic.
Attachments
Lines plan for the wooden mold
Lines plan for the wooden mold
The transparency
The transparency
Canopy completed
Canopy completed
Canopy completed
Canopy completed
Fit check
Fit check
Last edited by norm on 31 Dec 2019, 00:59, edited 1 time in total.
norm

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

Post by norm »

Wing structural analysis
Because the 1/3 scale model is the biggest model I have ever built, I conducted the wing structural analysis to confirm its strength. The analysis was done on the Excel work sheet. The conditions of calculation are: Total weight=10Kg, Center wing weight=1.93Kg, Outer wings weight=2.0Kg. Ultimate load factor=7.5.

Attatched graphs show the loads/stress and deflection distribution of the half wing. Wing STA 0 is the center of the fuselage and Wing STA 1000 is the center/outer wing junction. Wing STA 2655 is the wing tip. Lift and inertia loads dicrease outside the Wing STA 1000 because the outer wing is tapered.

Wing tip deflects more than 110mm and the stress increases toward the wing root but it decreases suddenly at STA 1000. This is because the center wing has larger spar frange than the outer wing. The maximum stress is around 19 Kg/mm^2 which occures at the wing spar frange STA 100 where the wing is supported by the fuselage. The wing spar frange is made of carbon square tube which has allowable stress around 70 Kg/mm^2, so the maximum stress is well below the allowable.

By the way the outer and center wings are joined at the STA 1000 with a carbon tube which has 20mm outer and 16mm inner dias. The maximum stress of this tube is calculated as around 18Kg/mm^2 which also is well below the allowable 70Kg/mm^2. Thus it was confirmed that the wing has sufficient strength.
Attachments
Loads distribution
Loads distribution
Stress and deflection
Stress and deflection
Last edited by norm on 31 Dec 2019, 00:52, edited 4 times in total.
norm

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

Post by norm »

Performance estimation
Before the first flight, I conducted the performance estimation of the 1/3 scale Mita. In contrast to the usual performance estimation where CL~α,CD~α,CM~α do not change with flight speed, they are changed with speed in my calculation because the Reynolds Number has a big effect in the 1/3 Mita's flight region. They are calculated by using the XFLR5. The glide ratio and the sink rate are calculated on the EXCEL spread sheet.

It is estimated that the maximum glide ratio is 22.5 and the minimum sink rate is 0.48m/sec for the weight of 10Kg condition. The real MIta's maximum glige ratio is reported as 30.8 and the minimum sink rate is 0.72m/sec.
Attachments
Glide ratio
Glide ratio
Sink rate
Sink rate
norm

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

Post by norm »

DWGs
Attached are the 1/3 Mita drawings. I want to donate these drawings to the SSUK. If you have any question please contact me by e-mail.
Attachments
Mita 2 View.pdf
(131.66 KiB) Downloaded 187 times
Mita AFT Fuselage.pdf
(57.1 KiB) Downloaded 141 times
Mita Canopy Wooden Mold Lines.pdf
(24.76 KiB) Downloaded 128 times
Mita Center Wing.pdf
(103.75 KiB) Downloaded 135 times
Mita Cowling & Farings.pdf
(103.96 KiB) Downloaded 130 times
Mita Fuselage.pdf
(419.46 KiB) Downloaded 135 times
Mita FWD Fuselage.pdf
(75.78 KiB) Downloaded 135 times
Mita Outer Wing.pdf
(213.98 KiB) Downloaded 137 times
Mita Tail Wings.pdf
(63.23 KiB) Downloaded 132 times
User avatar
Cliff Evans
Posts: 1032
Joined: 29 Dec 2019, 15:13
Location: Bristol
Contact:

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

Post by Cliff Evans »

On behalf of the community, thank you very much, Was getting a bit worried about you as you had not posted for a while!

For acrobat to display the fonts included in the pdf files you will need to download the file attache in this thread and change the file extension to .msi and install the font pack. Easy Peasy!
Attachments
FontPack1902120058_XtdAlf_Lang_DC.pdf
(60.17 MiB) Downloaded 146 times
https://lasercutsailplanes.co.uk
https://patteaklegliders.co.uk
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