PIK20 rebuild

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

Re: PIK20 rebuild

Post by StephenB » 06 Apr 2019, 05:39

Steady progress Peter, there looks to be a lot of work in those wing ribs :o

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

Re: PIK20 rebuild

Post by Peter Balcombe » 06 Apr 2019, 08:45

StephenB wrote:
06 Apr 2019, 05:39
Steady progress Peter, there looks to be a lot of work in those wing ribs :o
I let the laser cutter take the strain (courtesy of Cliff Evans - Laser Cut Sailplanes) as all of my built-up wing designs are produced in CAD, so I have cutting files available ;)

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Peter Balcombe
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Location: Clevedon, North Somerset, U.K.

Re: PIK20 rebuild

Post by Peter Balcombe » 06 Apr 2019, 17:03

Dummy LE & hinge spar planed/sanded flush with the ribs and the top skin applied.
Starting to look a bit more like a wing now.

Now the brake can be fitted from the top and servo hatch/cables fitted prior to adding the bottom skin.
Attachments
PIK20 LH wing top skin_small.jpg
LH wing with top skin fitted

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Peter Balcombe
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Location: Clevedon, North Somerset, U.K.

Re: PIK20 rebuild

Post by Peter Balcombe » 05 May 2019, 17:42

Now with wing skins on and fitted to the fuselage using the joiner box assembly
Attachments
Wings fitted.jpg
Wings fittted

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Peter Balcombe
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Re: PIK20 rebuild

Post by Peter Balcombe » 14 May 2019, 14:36

Having got the wing joiners fitted, attention turns to the tail feathers & having got Cliff Evans to cut some tailplane ribs & spars for me, it’s time to start glueing them together to produce a built-up tailplane.
Basic framework now together, with 3mm Liteply hinge & Aileron LE spars, prior to fitting balsa doublers to give 6mm hinge line thicknesses.
The Aileron LE will be angled for top hinging (tape).
The square ply plate in the centre is to locate & retain the fixing bolt (packed out with balsa to the rib outer profiles before adding skins)
I will probably add the balsa top skin next in order to provide a bit more rigidity prior to fitting the spar doublers.
Attachments
9E83EE5F-D6BC-4A21-833F-50B01FE5AE67.jpeg
Tailplane framework

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Peter Balcombe
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Re: PIK20 rebuild

Post by Peter Balcombe » 15 May 2019, 18:40

The top skins were attached as 2 pieces (partly to use up spare pieces of balsa sheet) after fitting the balsa block above the hold-down plate.
Turning the assembly over, the rib building tabs can be removed, fixing hole drilled through (using hole already in the ply plate) and then the 1/16” elevator LE spar doublers fitted behind the spar (which will be angled for down-going clearance), lower fixing plate balsa block added, plus spars sanded flush with the ribs.
Balsa infill also added in centre sections of the elevator to allow the rudder clearance cutout to be made later on.
3/16” Balsa doublers also fitted either side of the central ribs, forward of the hold-down plate, to allow for an anti-rotation peg to be fitted later.
Then, on with the bottom sheeting which is currently clamped up, using temporary spruce strips to ensure a straight TE.
Attachments
2F9528BC-3358-403E-BF2D-C695E94D11CB.jpeg
Tailplane ready for lower sheeting

GeeW
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Joined: 18 Mar 2015, 22:49
Location: Bracknell

Re: PIK20 rebuild

Post by GeeW » 16 May 2019, 18:10

Are you modelling the tailplane as per a 'b model or a 'd model PIK?
Just asking!

Regards

Gordon

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Peter Balcombe
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Re: PIK20 rebuild

Post by Peter Balcombe » 16 May 2019, 18:18

Gordon,
Good question, but I don’t know!
I have taken the outline from a PT kit foam tailplane core.
What’s the difference between a b & d versions?

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Peter Balcombe
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Re: PIK20 rebuild

Post by Peter Balcombe » 16 May 2019, 20:03

With the LE, TE & tips in place, we have a complete tailplane/elevator assembly which can be test fitted to the top of the fin before the previously installed internal block is fixed back into place.
Note that this assembly is intended to be a direct replacement for the standard foam cored version.
Attachments
PIK20 tailplane complete.jpg
Tailplane & Elevator complete
PIK20 with tail.jpg
It fits

GeeW
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Location: Bracknell

Re: PIK20 rebuild

Post by GeeW » 16 May 2019, 20:13

If the l/e of the tailplane matches with the l/e of the fin then it would be a 'b model. If l/e of tailplane overhangs the l/e of the fin by 100 mm (full size dimension) then it's a 'd. The reason for this was so that they could extent the top of the rudder upwards by a similar amount to give a bit more rudder area.
There are full size 'b fuselages with the 'd tailplane and vice versa so what ever way you do it you can call it scale!

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