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Re: PIK20 rebuild

Posted: 20 Apr 2020, 10:58
by Peter Balcombe
Having decided to try to fit out the cockpit a bit, I went for a moulded epoxy glass seat - which is a essentially a curved plate.
First off, I scaled & drew out the side profile and then cut a foam blank, keeping the top part for use later.
Then, with pieces of thickish plastic sheet as the release layers, I laid up 3 layers of 300gsm cloth between an outer layer of 200gsm cloth directly onto the plastic sheet protected foam bed - using the upper foam blank under weights to squeeze everything together whilst it cured.
The resultant curved glass sheet was easily released from the foam blanks & cut to size.
The photos below show some of the steps, plus the resultant fit using my old AH Designs 1/4 scale pilot.
All seems to fit ok, so next job will be to make up the instrument panel binnacle base.

Re: PIK20 rebuild

Posted: 22 Apr 2020, 14:41
by Peter Balcombe
Prior to attacking the instrument panel binnacle, I decided that I ought to get the aerotow release & associated servo fitted.
I therefore took an impression of the inside of the nose, transferred this to a female mould & then cast a lead nose weight.
With a hole drilled through the lead and counter-bored at the rear, the tow release was epoxied in position prior to the whole assembly being set into the nose using silicone sealant - all the better to be able to remove if needed at a later date ;)
I installed an old Turnigy metal cased servo on a ply plate & will now make up the pushrod to complete this aspect.

Re: PIK20 rebuild

Posted: 24 Apr 2020, 19:41
by Peter Balcombe
With the canopy frame now painted, the glazing has been attached.
Meanwhile, an instrument panel & binnacle is under construction.

Re: PIK20 rebuild

Posted: 26 Apr 2020, 16:34
by Peter Balcombe
Decided to get the fuselage repainted whilst the good weather lasted ;)
Have also just finished the Instrument panel binnacle which has been fitted with a panel kindly supplied by Cliff Evans. (Yes, the top left instrument is blue on the full size!)
The intention is to install the binnacle using location pins & magnets so that this is removeable in order to access the nose.

Re: PIK20 rebuild

Posted: 26 Apr 2020, 23:39
by Jolly Roger
Peter Balcombe wrote: 26 Apr 2020, 16:34 Decided to get the fuselage repainted whilst the good weather lasted ;)
Well it is a Sunday..."let us spray".
See what I did there?

Re: PIK20 rebuild

Posted: 06 Jul 2020, 18:48
by Peter Balcombe
After a further delay - forgot to spray the rudder :oops:
We now have a completed model at last (bar Rx & straps to hold the pilot down!)
Overall weight when ballasted to get CoG 60mm behind the wing LE (front of main spar, it says on the original instructions) the AUW comes out at just under 9lbs 3oz, or 4.1Kg in new money.
This sits very well with the 9.5-10.5lbs flying weight on the original instructions bearing in mind the rear fuselage/fin repair.

Now to find a spare Rx & tie the pilot down before a trip to Crook Peak ....

Re: PIK20 rebuild

Posted: 07 Jul 2020, 11:25
by StephenB
Lovely job Peter, the PIK 20 is such a good looker - I prefer this era to the more modern ultra streamlined ships.

Re: PIK20 rebuild

Posted: 07 Jul 2020, 12:53
by MDev
Nice one Peter, the Pik20 always looks so well proportioned.

M

Re: PIK20 rebuild

Posted: 09 Sep 2020, 17:05
by Peter Balcombe
The rebuilt PIK20 was successfully flown today at Crook Peak - after jacking up the rear of the tailplane by 3mm! - followed by an uneventful landing :)
First launch attempt resulted in a dive into the gorse - luckily without damage.
Inspection of the tail angle (fuselage previously broken, so should have double checked that before now :? ) showed what looked like a negative decalage, so the tailplane bolt was loosened & a couple of strips of scrap fibreglass board slipped in at the rear.

I now need to double check the decalage, as I think a little more under the tailplane wouldn’t hurt. I still needed full up trim & a little up stick to fly level. It may be a little nose heavy, but can look at that when I can get it trimmed for level flight.