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Re: TYPE 13 PETREL 1/4 SCALE

Posted: 07 Feb 2020, 16:45
by Peter Balcombe
SedB wrote:
07 Feb 2020, 11:17
You build at the speed of light :o
Since I'm not an experienced builder, I learn a lot from this, so thanks for sharing!!

Looking great so far!
Seb,
Think time-lapse photography ;)

Re: TYPE 13 PETREL 1/4 SCALE

Posted: 07 Feb 2020, 19:58
by chris williams
Actually, there are hidden benefits to building at the speed of light...Thanks to Einstein's work on Time Dilation Theory, by the time this build is completed I will have aged only a few hours, whereas you lot will be many years older 8-)
(In fact, if I could just speed up a little more, I could finish the Petrel before I even started it)

Re: TYPE 13 PETREL 1/4 SCALE

Posted: 08 Feb 2020, 10:11
by chris williams
On this version, I have included a de-bananariser for the tail end in the form of a 3mm lite ply template to sit between the spars and keep the tail end straight...

The filler for the nose needs to be applied in stages, 3 or 4 usually, otherwise gravity will cause bulges to form that will need extra elbow grease to remove...

Re: TYPE 13 PETREL 1/4 SCALE

Posted: 09 Feb 2020, 10:05
by chris williams
Before much more can be done to the fuselage, the rear end needs to be sorted out. I have always found it best to set up the AMT as far as possible, before finally attaching the fin to the fuselage...

Re: TYPE 13 PETREL 1/4 SCALE

Posted: 10 Feb 2020, 10:23
by chris williams
The AMT leading edges are made up from solid balsa, tapered and sanded to shape. The Fin is covered with 0.6mm ply, ready for setting up the AMT

Re: TYPE 13 PETREL 1/4 SCALE

Posted: 11 Feb 2020, 09:35
by chris williams
For builders of the Petrel, the all-moving tail poses a bit of a dilemma... A quick bit of History: there were three Petrels built originally; one crashed, two remain. The best known of the two is Graham Saw's red Petrel, but here's the rub...Sometime during its history, the AMT was substituted with a conventional tailplane, that of a Rhonbussard if I remember correctly. I think most would agree that the AMT is a much more elegant shape than the substitute, so here we have a situation where even the iconic full size is not 'scale'. (The other 'scale' Petrel has been beautifully restored to it's original wood & varnish finish in the USA)
So, I make no apologies for using the original tailplane set up. I hope the diagram makes clear how it works: the tube in the fin hosts the AMT joiner bar, and the bellcrank rotates around the tube in the fin...

Re: TYPE 13 PETREL 1/4 SCALE

Posted: 11 Feb 2020, 11:21
by Cliff Evans
You could give the option on both tailplanes Chris. I know it is more work but.....

Re: TYPE 13 PETREL 1/4 SCALE

Posted: 11 Feb 2020, 12:53
by chris williams
I can offer the drawing from my 3.5 scale version, scaled down, but I'm not building two fuselages...!

Re: TYPE 13 PETREL 1/4 SCALE

Posted: 11 Feb 2020, 14:26
by Barry_Cole
I can offer the drawing from my 3.5 scale version, scaled down, but I'm not building two fuselages...!

Go on, you know you want to....

8-) 8-) 8-) 8-)

BC

Re: TYPE 13 PETREL 1/4 SCALE

Posted: 11 Feb 2020, 15:44
by Cliff Evans
It would only take you 5 mins with your time machine!