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Re: PIK20 rebuild

Posted: 16 May 2019, 20:33
by Peter Balcombe
Gordon,
In that case, it seems to be halfway between a b & d version as per the PT original design.
The tailplane overlaps by about 12mm, so around 50mm on full size ;)
The rudder stops below the elevator & the top front of the rudder is slightly scalloped to provide elevator TE clearance.
I wouldn’t be surprised if Pat based his design on a b version & enlarged the tailplane slightly to improve handling.

Re: PIK20 rebuild

Posted: 17 May 2019, 13:21
by Peter Balcombe
A view of the original PT PIK20 build instructions versus the fin top part of my CAD plan.

Re: PIK20 rebuild

Posted: 17 May 2019, 20:13
by GeeW
Plan fuz is definitely a 'd model. L/e position relative to edge of canopy frame line gives it away.

Re: PIK20 rebuild

Posted: 21 May 2019, 20:38
by Peter Balcombe
Ok, on with the elevator servo & linkage installation.
I made up a simple cardboard template to hold the servo & bellcrank plates in the correct position relative to the rear of the fin, fitted the servo to its plate & the bell crank to its plate & used the jig to make up the pushrods to correct length.
The jig card was then reduced to minimum size to register the plates when these were taped in, then Polyester resin applied to the bottom of the plates before placing the jigged assembly into the fin & aligning the jig with the fin rear edge.
A piece of spruce used to hold the side of the fin straight & a couple of temporary wedges to hold the plates down whilst the resin cured - job done :)

Re: PIK20 rebuild

Posted: 30 May 2019, 21:40
by Peter Balcombe
Rudder now in place and the flap & aileron made for the 2nd wing.
All flying surfaces about ready to be glassed.
MPX wing connector harnesses made up & ready to be bonded into the fuselage wing root.
Time to get on with the canopy.

Re: PIK20 rebuild

Posted: 12 Apr 2020, 18:24
by Peter Balcombe
With a couple of projects now off the workbench, its time to return to the PIK20 to finish the fuselage outfitting & canopy.

So.. looking at the cockpit coaming, it was evident that both sides had been nibbled by a previous owner, so a decision was needed as to whether to build the coaming width back up to the original width, or reduce to a uniform width.
I chose the latter, so after marking a new line, I attacked the coaming with a half round file to arrive at a better shape.
Next job was to fabricate a canopy frame, so I started with a solid 3 part 3mm Liteply base & added a doubler strip around the edges to give a bit more canopy glueing area.

Although the previous owner had fitted a solid canopy frame without a pilot, the plan is to remove the central area of the initial canopy assembly build to make a recessed pan which can then be equipped with instrument binnacle, seat, full length pilot etc.
In order to be able to get at the pilot after glazing the canopy, I plan to make the bottom of the pan removeable, but alternatively I could go the whole hog & make the bottom of the canopy frame completely open, fitting everything into the fuselage itself - watch this space to see how this develops ;)

Re: PIK20 rebuild

Posted: 13 Apr 2020, 17:47
by B Sharp
I am really enjoying this build/rebuild Peter. I had two of these in the distant past and absolutely loved them. One was built as a sport model and the second was built for Scale cross country events (I remember them through a sweaty haze – just ask Chris Bowles) The sport model died when my son tried a square loop and was a little enthusiastic on the elevator. The second I flew for many years and then sold on.
I suspect that you will enjoy yours when you get it finished.
Brian. :)

Re: PIK20 rebuild

Posted: 13 Apr 2020, 19:06
by Peter Balcombe
Many thanks for the kind words Brian.
I think the Scale Police would be wanting a word with your pilot, but he appears to have gone AWOL :o

I’m currently waiting for the warm weather to reappear in a couple of days before moving on with the canopy frame in order to avoid putting the heater back in the workshop.
I’ve decided to fret out the inside of the initial frame (after removing the doubler strips :? ) to leave a narrow frame which will be stiffened up using a sandwich of glass & 1/16” ply top.

Re: PIK20 rebuild

Posted: 14 Apr 2020, 09:54
by Chris Bowles
Hi, that was the time when we could carry a large plane up a big hill, and then run around all day and enjoy it,at least we can still remember it Brian,
Peter, it's nice to see your rebuild, have been following it, it does bring back memories of my own builds of Pat's models, always thought the Pik20 flew the best of Pat's planes, the first Pik20 I saw, was when Mr Baker brought up a green Pik20 to Crook Peak in the early 70's, that flew well also
Chris

Re: PIK20 rebuild

Posted: 16 Apr 2020, 16:33
by Peter Balcombe
Canopy frame sandwich made using layer of 200gsm glass above & below the initial frame, capped with a layer of 1/16" ply.
The fuselage coaming was protected using a layer of glossy tape to act as a release layer & the assembly could be clipped to the fuselage whilst the epoxy cured to get a good shape.
Once cured, the frame was cleaned up (including removing front section) and has now been fitted with front peg & 3 rear magnets.