Jastreb J 21 - 1/4 scale model
Aleš Gasparič & Jastreb J21
Jastreb J 21 is 1/4 scale jet model made from "Mirce models" wooden kit.
Almost 300 hours was used to draw complete model in Catia 3D program!
All parts are cut on laser cut machine.
Scale: 1/4
Wingspan: 2920 mm (115") with tip tanks / 2620 mm (103,1") without tip tanks
Length: 2650 mm / 104,3"
Weight: around 18 - 20 kg / 37,5 - 39,6 lbs
Wing area: 103,75 sq/dm / 1608 sq/in
Turbine: 180 - 200 Nm
Radio: minimum 6 channel
Short wooden kit 1/4 scale - 675,00 Euro
- 3D printing tanks parts - 50,00 Euro
- Hinges and horns from G 10 material - 40,00 Euro
- Laser cut servo lid & holder - 10,00 Euro
More about this products you can see here.
For scale surface finish:
- Detail set for Galeb G2 - 55,00 Euro
- Finish set - 69.90 Euro
- Extra rivets set - 75,00 Euro (35.000 rivets)
RECOMMEND:
- SMT-RC - official dealer for canopy and front light plastic
- CM Jets - official dealer for main and UAT Kevlar tanks
- Grumania - for two wall thrust tube with inlet part
Parts from list are used in model we build.
Covering the air frame with 80 gr/sq meter fiberglass cloth and epoxy resin.
Info, tech support & help in building process on e-mail at: mirce.rc@gmail.com
UPDATE !!! (november 2024)
The time has come to update "Mirce models" wooden kits of the Jastreb J21 & Galeb G2 in 1:4 scale.
The concept of the wing remained the same - a center panel with two outer parts of the wing.
The middle part is 1400 mm wide, goes from end to end of the flaps and has landing gear on it.
You do not have to remove this part from the fuselage, you have the option to transport Jastreb J 21 on wheels!!!
The profile, the place where the wing splits, how it is mounted on the fuselage are also unchanged.
Of course, as always "Mirce models", first draw everything in a 3D program!!!
Unlike the earlier concept, the wing is now made on a template plate.
The ribs of the profile have "legs" that fit into precisely defined grooves on the template.
Profile ribs are connected by vertical parts.
Everything fits like a Puzzle!!!!
The precision is perfect, the production is quick and easy.
The other big change is that there are no more spars and wooden bayonets for connecting the two halves of the center panel.
Now, an aluminum tube with a diameter of 30 mm at the front and 22 mm at the back is glued into the center panel.
Center panel is strong, you can jump on it, it won't move...
The outer panels are also connected to the center plane with aluminum tubes with a diameter of 30 mm.
You can replace the aluminum tubes with carbon ones, if you want to save weight...
Furthermore, the ailerons now have a different hanging concept.
Since the wing has curve on the ends, the aileron is made on its template!!!
There are also changes on the tip tanks, and they will be made on templates and with two screws they will be able to be dismantled for easier transport.
Some parts of the tank will be printed on a 3D printer.
Building process of the new design 1/4 scale Jastreb J 21 you can see in next albums:
Wing:
https://postimg.cc/gallery/GyNhYP9
Ailerons:
https://postimg.cc/gallery/wyThGrz/758667c2
Flaps:
https://postimg.cc/gallery/YpT7G1s
Fuselage:
https://postimg.cc/gallery/SKK1KtW
Elevator:
https://postimg.cc/gallery/0zS4Zz5/a79c016b
Wing tanks:
https://postimg.cc/gallery/nrq0Njx/6451615f
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Jastreb J 21 in the air:
https://www.youtube.com/watch?v=qupgsvlSLH0
https://www.youtube.com/watch?v=1iqxrE_y_XU&t=15s
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Building process of 1/4 scale Jastreb J 21 you can see in next albums.
Old version, before november 2024!!!!!
Fuselage:
https://postimg.cc/gallery/1pgfwv4qm/
https://postimg.cc/gallery/34576nc1q/
Wing:
https://postimg.cc/gallery/363zpt51a/
https://postimg.cc/gallery/106xn27y6/
Elevator:
https://postimg.cc/gallery/30pkrgf5q/
Tip tanks:
https://postimg.cc/gallery/1x96e0yim/
Glassing & primer:
https://postimg.cc/gallery/1wn67lpz2/
Parts installation:
https://postimg.cc/gallery/xcttj1vi/
Finish model & maiden flight:
https://postimg.cc/gallery/1br0vls8u/
Details & painting:
