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Old Dec 02, 2012, 03:20 PM
Mr Whirl is offline
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Gone Gas! / Gone Crazy?
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United States, WA, Redmond
Joined Sep 2012
1,086 Posts
Crack Yak S (Super) Reporting For Duty!

2x 4g Digital servos (rudder/elevator) Twisted Hobbys
1x 9g Digital servo (ailerons) Twisted Hobbys
Out-runner1450kv 24g Twisted Hobbys
Esc 12 Amp Twisted Hobbys
2s 325mah lipo battery Thunder Power
9x4.3 Tuff Prop
AUW 194g

Super Crack Enhancements
Cross drilled carbon spar & hollow carbon tube torsion bar.
Carbon tube reinforcement tail
Carbon Control horn, push rod guides, motor mount & landing Gear.
Micro Ball Links
Rubber bushing motor mounting for adjustable thrust angle.
Polystyrene angle stk motor / fuselage reinforcement
Blenderm tape reinforced hinge points

I think there is still an additional 20grams that could be shed. Lighter 19g motor / 20g Lipo / 5g hollow carbon spar / Less Welders glue usage / Etc. My custom hollow spar turned out too thick 7mm & too heavy 15g so I opted with plan B an extensively cross drilled & lightened solid carbon spar 3mm thick at 10g. The stk wood spar weighs 7g but was not nearly as torsionally stiff. I also ended up with slight alignment issue with the elevator servo, control arm & push rod guides which reduced elevator travel to 45 degree verse a potential 60. A Lesson learned for next build. We will see if all the effort and R&D makes any difference in flight performance.
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Last edited by Mr Whirl; May 08, 2014 at 08:11 PM.
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