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Jan 14, 2015, 07:06 PM
"Five Easy Pieces"
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"5EZP" Su-25 FROGFOOT


From Wikipedia, the free encyclopedia

Su-25

Role Close air support
Manufacturer Sukhoi Design Bureau
Tbilisi Aircraft Manufacturing (former)
First flight 22 February 1975 (T8)
Introduction 19 July 1981
Status In service
Primary users Russian Air Force
Belarusian Air Force
Ukrainian Air Force
North Korean Air Force
See Operators for others
Produced 1978–present
Number built Over 1,000
Unit cost
US$11 million[1]
Variants Sukhoi Su-28
The Sukhoi Su-25 (NATO reporting name: "Frogfoot") is a single-seat, twin-engine jet aircraft developed in the Soviet Union by the Sukhoi Design Bureau. It was designed to provide close air support for the Soviet Ground Forces. The first prototype made its maiden flight on 22 February 1975. After testing, the aircraft went into series production in 1978 at Tbilisi in the Soviet Republic of Georgia. Russian air and ground forces nicknamed it "Gratch" ("Rook").

Early variants included the Su-25UB two-seat trainer, the Su-25BM for target-towing, and the Su-25K for export customers. Some aircraft were being upgraded to Su-25SM standard in 2012. The Su-25T and the Su-25TM (also known as the Su-39) were further developments, not produced in significant numbers. The Su-25, and the Su-34, were the only armoured, fixed-wing aircraft in production in 2007.[1] Su-25s are in service with Russia, other CIS states, and export customers.

I'm leaning toward modeling the "UB" or two-seat trainer version.
She is 42" long with a 42" wingspan.
Began the pattern cut-out this evening.
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Jan 15, 2015, 01:08 PM
"Five Easy Pieces"
Thread OP
"5EZP" FROGFOOT GLIDES (2 min 5 sec)
Jan 15, 2015, 01:45 PM
Slip the surly bonds...
Sopwith Mike's Avatar
Frogfoot Glides!

Lovely video and music Bob. It reminds me of gliding a Keil Kraft Avro 707 out of my third floor bedroom window in the late 1950s. Those were the days...no traffic to run over the model...kits cost under 2/6...balsa cement tasted great off your finger ends...aaaah
Jan 15, 2015, 06:16 PM
skumgummi dave
Thumbs up Bob!
Jan 15, 2015, 08:54 PM
"Five Easy Pieces"
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Quote:
Originally Posted by Sopwith Mike
Frogfoot Glides!

Lovely video and music Bob. It reminds me of gliding a Keil Kraft Avro 707 out of my third floor bedroom window in the late 1950s. Those were the days...no traffic to run over the model...kits cost under 2/6...balsa cement tasted great off your finger ends...aaaah
Thanks Mike.
Tossing them from high up is the best. At my big house I just tossed them over the pool cover. I do worry about the alley traffic here.
Jan 15, 2015, 08:59 PM
"Five Easy Pieces"
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Now with gear.
The white disk is my 6" prop clearance piece.
I will be using the same set-up I did with my "5EZP" YAK-130.
She is 41" long with a 42" wing-span.
Jan 16, 2015, 09:13 PM
"Five Easy Pieces"
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The second FROGFOOT is cut out and taped together for fit.
Here it rests in the model stand with the first FROGFOOT mock-up to the left.
Jan 16, 2015, 10:20 PM
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rajazo's Avatar
it's looks great Bob!!!
Jan 17, 2015, 09:15 AM
"Five Easy Pieces"
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Quote:
Originally Posted by rajazo
it's looks great Bob!!!
Thanks Rajzo.
I like your Bronco build thread too.
Always wanted to do that one.
This "5EZP" Frogfoot has nacelles deep enough to allow it to take-off and land on it's belly without landing gear.
Should be fun.
Jan 18, 2015, 04:46 AM
Registered User
Hey Bob!
Great job - as always!
It is funny though, I have just started a scratch build single EDF version of SU-25T. Both have the same glider configuration, but I did not fine any info on CG location...
Would you share yours, measured from wing root?
Thanks!
Jan 18, 2015, 05:20 PM
"Five Easy Pieces"
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Quote:
Originally Posted by Teilchen
Hey Bob!
Great job - as always!
It is funny though, I have just started a scratch build single EDF version of SU-25T. Both have the same glider configuration, but I did not fine any info on CG location...
Would you share yours, measured from wing root?
Thanks!
I've been using the standard 30% of the wing cord with success. I usually put my fingers just inboard of the leading edge off-set to balance it. See my glide vid.
I just ordered two 64mm 4400kv EDF's for a twin EDF version of the FrogFoot I want to do with retracts.
Jan 18, 2015, 05:22 PM
"Five Easy Pieces"
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All glued together and ready for gizmos.
She is 41" long with a 42" wingspan less tail and nose booms.
She will be powered with a Grayson Hobby SMJv2 spinning a 7x5 Prop and have a aileron, elevator and rudder set-up. No fixed gear yet. Gonna maiden her without it.
I just ordered two GH 64mm 4400kv EDF's to try twin EDF version later.
They only produce 24oz. each on a 3S so I hope I can get the full 48oz thrust out of the two on 4S.
may do retracts on the EDF Version if I can keep the weight under control.
Last edited by bobdaeronort; Jan 19, 2015 at 08:09 PM. Reason: content
Jan 19, 2015, 08:06 PM
"Five Easy Pieces"
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DONE.
Still in her "Natural Commie Pink" colors and
Ready for her Maiden flight tomorrow in the January sunshine.
Showed her to the guys at the Local Temptation Parlor (Hobby Barn) but they did not care for the commie pink color either.
Length 41", wingspan 42" flying weight 26.5oz. power - GH SMJv2 w/ 7x5 prop , 50A ESC, 2200mah 3S LiPo, with four servos: Ailerons, Elevator, and Rudder.
Last edited by bobdaeronort; Jan 19, 2015 at 08:12 PM.
Jan 20, 2015, 02:51 AM
Registered User
That's great!
Waiting to see the maiden.
Could you please share more fotos of ruder and elevator servos? Did you do the 5deg. V- tail on horizontal stabilizer?
Jan 20, 2015, 07:28 AM
"Five Easy Pieces"
Thread OP
Quote:
Originally Posted by Teilchen
That's great!
Waiting to see the maiden.
Could you please share more fotos of ruder and elevator servos? Did you do the 5deg. V- tail on horizontal stabilizer?
I'll do a walk around video soon and post more pics here too.
The horizontal stab does tip down in a slight V but not sure it is 5 deg.
Hope to take her out after sun up here.


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