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68% Challenger 2 Biplane
Posted: October 29th, 2013, 7:36 pm
by robbieskipton
On the 2nd September 2013 i received my first lot of wood from none other than slec uk.
After only 1 Month in design, We have been busy cutting, Gluing and generally making mess to achieve all needed parts to make my new aircraft for the 2014 Season ( Which will be here sooner than we think!)
So here goes to the new build thread on this model.
Lets start of with the general specs
Wing Span - 3.68m (144 Inchs)
Length :- 3.96m (156 Inchs)
Servos - 4 x Jr 8911 On Rudder - 3 x Spectrum A6030 per elevator side ( 6 In Total)
8 x Spectrum A6030 for ailerons
Engine - 3W 342ts
Prop - 42 X 10
AUW (Anticipated 85 - 90 LBS RTF)
Re: 68% Challenger 2 Biplane
Posted: October 29th, 2013, 7:47 pm
by robbieskipton
After 4 Days, we had the elevators, Stabs, Rudder and fin completed including Servo Hatches.
As the Tails are all flat ( No Aerofoil) This mate the assemble simple.
The center part of the surfaces are made from 6mm Light Ply, then sheeted over with 25.4 x 12.5 Balsa Strio
Re: 68% Challenger 2 Biplane
Posted: October 29th, 2013, 7:54 pm
by robbieskipton
On To the bottom wings.
Simple Standard construction with 2 Main Spars.
both bottom wings took almost 2 Weeks to complete, including ailerons, Glassing main spar and rear spar.
Total Weight For each wing is a very light 6lbs including ailerons

Re: 68% Challenger 2 Biplane
Posted: October 29th, 2013, 7:57 pm
by robbieskipton
So on to top wings and ailerons:)
same construction as bottom wings but slightly bigger

Re: 68% Challenger 2 Biplane
Posted: October 29th, 2013, 8:04 pm
by robbieskipton
So Now the more fun Bits

The interplain Struts
As we had to build interplane Struts before putting on body ( As we have not got the steel work for center section) We had to make jigs to make sure the wings were perfectly aligned with no incidence, Then Build up the interplanes to suit.
Over the total Length of the wings, were not perfect, but within 2mm Is not bad

Re: 68% Challenger 2 Biplane
Posted: October 29th, 2013, 8:11 pm
by robbieskipton
So... On To the next bit
The Fuselage.......
As most know, a Biplane fuselage is practically empty space with a bit of shape.
All the fuselage is build from the center up, So we made a start!
In total 2 days to complete up to this stage
Re: 68% Challenger 2 Biplane
Posted: October 29th, 2013, 8:17 pm
by robbieskipton
So now not 8 Weeks since we began the build, we have had the first inspection from no other than MR HOOPER ( Today 29/10/2013)!
we now have permission to finish the build up to point of covering

So how we looking on weight..
Wings - 24 Lbs
Tails, Rudder and Stabs - 7lbs
Engine Box - 3Lbs
Interplain Struts - 2Lbs
Fuselage - 16Lbs
Total Weight - 52LBS
So with the Sheeting for fuselage will get the weight of fuselage up to 18LBS!
Engine, and electronics Undercarrage weighs in at 33LBS
So Total Weight is well within out original estimates at 87LBS RTF.
More Pics to come tomorrow (30/10/2013)
Re: 68% Challenger 2 Biplane
Posted: November 9th, 2013, 8:32 am
by stewart clifford
Looks very well thought out, good stuff Robbie.
Re: 68% Challenger 2 Biplane
Posted: February 6th, 2014, 10:03 pm
by robbieskipton
Well thought i would post another set of pics of what we have been whittling..
We have had a good few days on her so far, most of the graphics are now on the plane, then on to install on 80 Meters of cable, powerbox, tanks and receivers.......
i will put a roundel on it somewhere... Maybe inside instead of the smiley man as previously seen on the Yak 54

Re: 68% Challenger 2 Biplane
Posted: February 13th, 2014, 3:19 pm
by James Stewart
Nice one Robbie, whats that sticking out the top of the cowling?
Re: 68% Challenger 2 Biplane
Posted: February 16th, 2014, 7:06 pm
by robbieskipton
its the intake manifold
Re: 68% Challenger 2 Biplane
Posted: February 16th, 2014, 7:22 pm
by DAVE JOHNSON
Robbie--that scheme looks superb--really looking forward to seeing this one at this years shows---
Re: 68% Challenger 2 Biplane
Posted: February 17th, 2014, 8:08 am
by Dave Parry
Ooh! To be so talented and young as well,

well done Rob, can’t wait to see it being put though the Robbie routine.