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Scratch built Pilatus B4 to 1/4 scale.

Let us all watch your new project progress.
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Peter Balcombe
Posts: 1043
Joined: 18 Mar 2015, 10:13
Location: Clevedon, North Somerset, U.K.

Re: Scratch built Pilatus B4 to 1/4 scale.

Post by Peter Balcombe »

Looking very nice Brian.
Nice even planking.
Are you preparing to fit a fixed mainwheel or retract?

Peter

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B Sharp
Posts: 706
Joined: 19 Mar 2015, 17:18
Location: Perthshire

Re: Scratch built Pilatus B4 to 1/4 scale.

Post by B Sharp »

Thanks Peter. The wheel will be retractable as in the photo of the full size on page 1. As I said at that point I made a retract mechanism a couple of years ago from plans on this forum and have been looking for an airframe to put it in. There is a photo also on page 1.
Brian. :)

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Peter Balcombe
Posts: 1043
Joined: 18 Mar 2015, 10:13
Location: Clevedon, North Somerset, U.K.

Re: Scratch built Pilatus B4 to 1/4 scale.

Post by Peter Balcombe »

Brian,
Now that you you have reminded me, I remember the comment about the available retract mechanism.
I look forward to seeing it finished before too long.
Peter

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B Sharp
Posts: 706
Joined: 19 Mar 2015, 17:18
Location: Perthshire

Re: Scratch built Pilatus B4 to 1/4 scale.

Post by B Sharp »

Things are very busy for me at the moment despite “lockdown” so I’m only managing one post per week on average. So here’s what I’ve done in the last week.
The fin has been finished off and a rudder built, hinged and temporarily mounted. I created ply outlines for the nosecone and glued them to the fuselage. I find that I can get a much better final nose profile when I do this. The quarters were then filled with of-cuts of balsa and planed to a rough outline before final sanding to shape. I think it looks Ok!
Brian. :)
Attachments
Tailend with rudder attached.
Tailend with rudder attached.
Ply nose profiles in place.
Ply nose profiles in place.
Rough carved.
Rough carved.
The final nose-job.
The final nose-job.

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B Sharp
Posts: 706
Joined: 19 Mar 2015, 17:18
Location: Perthshire

Re: Scratch built Pilatus B4 to 1/4 scale.

Post by B Sharp »

I stole another hour in the workshop this afternoon and have now got the retract mechanism sitting happy in its little home. It did take a little fettling of a couple of lower formers which I had made a little too neat but is now fitting in quite snugly. The fuselage is now going to be set aside for a while.
I now require a couple of wings and the wing supermarket is closed at present. What will I do? Perhaps I should build them from this pile of wood I have stacked in the corner. Watch this space!
Brian. :D :D :D
Attachments
Retract fitting neatly in the fuselage.
Retract fitting neatly in the fuselage.
Plenty of clearance for the wheel.
Plenty of clearance for the wheel.

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Cliff Evans
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Joined: 29 Dec 2019, 15:13
Location: Bristol
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Re: Scratch built Pilatus B4 to 1/4 scale.

Post by Cliff Evans »

Slec are still open and delivering!

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B Sharp
Posts: 706
Joined: 19 Mar 2015, 17:18
Location: Perthshire

Re: Scratch built Pilatus B4 to 1/4 scale.

Post by B Sharp »

I have made a little more progress, this time on the wings. Once again I have made a bit of a rod for my own back. The inner section of each wing is parallel chord so I was able to make a 1/16 ply template and cut each rib individually using that. However the outer section is tapered so each rib is of course different. In the past I have used the sandwich method of producing the ribs but have never found it entirely satisfactory. This time I printed out a copy of each individual rib from Profili, tack glued it to the balsa sheet and cut out two copies. Very time consuming but I now have all my ribs exactly the correct size (in theory). :)
You will notice that I have cut each rib with building tabs on the upper surface. This is because I am going to build the wings upside down. The reason being that the top surface of the wing is completely flat and the thinning of the wing due to the wing tip taper happens entirely on the lower surface. Hopefully this will not provide me with too many problems during the build. :roll:
Next job? Splicing and tapering spars! :?
Brian. :)
Attachments
Two wings worth of ribs.
Two wings worth of ribs.

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RobbieB
Posts: 568
Joined: 07 Mar 2015, 22:22
Location: North West

Re: Scratch built Pilatus B4 to 1/4 scale.

Post by RobbieB »

Dear oh dear oh dear.

Brian, what is going on? Wonkey tops, bottles not standing up to attention - really poor show - must do better.
B4 032.jpg

StephenB
Posts: 131
Joined: 26 Dec 2018, 08:45
Location: Hungary

Re: Scratch built Pilatus B4 to 1/4 scale.

Post by StephenB »

Very nice work Brian, reminds me of my Fauvette build with all that planking. I cut my planks to 3/8" width bevelled each side, yours look to be thinner which in hindsight mine should have been as yours looks a neater/tighter finish requiring less filling.

Will you be risking this on the slope with that retract?

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B Sharp
Posts: 706
Joined: 19 Mar 2015, 17:18
Location: Perthshire

Re: Scratch built Pilatus B4 to 1/4 scale.

Post by B Sharp »

Robbie, I will cop to the wonky tops but the upside down bottle is me getting the very last dregs of epoxy out of the bottle (I'm a thrifty Scotsman don't yo know).
Stephen, most of my planks were either 1/2 by 1/8 or 1/4 by 1/8 on the tighter sections. I also bevel the edges of each plank to get a better fit. I also soak the planks in water to get them round the trickier curves. Most of my flying is on the slope but the retract is there for the occasions that I aerotow. I also have one slope which has a (very) small, neat grass, landing area where I drop the wheel if my approach looks right.

I have made a start on the wing construction this afternoon and so far so good. Everything has fitted together quite well with no major fiddling and fettling. The carbon joiner tube fitted quite snugly and appears to be at the correct angle. I am pretty content with my afternoons work and feel I have almost achieved “Williams” pace! :D :D :D
I will probably leave the whole assembly to set and settle overnight before fitting the bottom main spar and starting on the webbing between the spars.
Brian. :)
Attachments
One upside down left wing panel.
One upside down left wing panel.

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