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Re: SZD30 Pirat

Posted: 16 Feb 2019, 17:07
by RobbieB
The balsa planking might be an issue but not convinced. My Skylark is 0.8mm ply back at the main wing former with the fuz covered in Diatex and glassed internally.

Not clogging the thread up John, all interesting stuff.

Re: SZD30 Pirat

Posted: 16 Feb 2019, 18:49
by Richard Farrer
This is all interesting stuff. Thanks everyone for joining in. I have done as suggested and drawn the camber line of the Pirat aerofoil and attached two photos. I don't know if the camber is defined as the maximum distance that the camber line deviates from the chord line but if it is then this aerofoil has 2.7% camber.
The next thing I did was to measure the decalage with my amazing incidence meter and surprise, surprise with the tailplane at zero I have 2 degrees incidence on the wing. Built to the plan which shows 5.5 degrees; it must be my inaccurate building. Photos show incidence meter in place on tailplane and the wing. Checked it twice same result.The wing is a snug fit on the fuselage so I am happy with that. I will fix the wing with the locating tongue at the back and two nylon bolts at maximum wing thickness.
This exercise required first assembly of model so I had to include pics of that.

Re: SZD30 Pirat

Posted: 16 Feb 2019, 18:53
by Richard Farrer
Some photos didn't upload so try again.

Re: SZD30 Pirat

Posted: 16 Feb 2019, 22:53
by RobbieB
Richard,

A cautionary note about incidence gauges - or more precisely, the mounting mechanisms for them.

Unless the LE of the wing is fully symmetrical about the chord line, which it is only with a symmetrical section, and most are not, you can have some inaccuracy in your measurement when using a 90ยบ cut-out in the mounting frame on the gauge.

IMG_0054.JPG

I do like that inclinometer for the phone - must have a look at that.

Re: SZD30 Pirat

Posted: 19 Feb 2019, 10:27
by Richard Farrer
Another good point, I hadn't thought about that one. Quick check and, phew, all Ok with this wing section.
IMG_20190219_101342885.jpg

Re: SZD30 Pirat

Posted: 24 Mar 2019, 19:15
by Richard Farrer
It seems a long time ago since I started this build but it is now finished and I await a suitable day to heave her off a local slope. I love the shape of this glider and look forward to seeing her in the air.
Including 860g of lead in the nose she weighs 4.4kg, a whole kilo lighter than my previous Pirat despite trying to build her to be strong.
Whilst I am pleased with the outcome of this build I must repeat that the plan is inadequate in many respects. It might have been better to have bought a kit especially as they were on offer shortly after I commenced my build.
Lovely day today so photographs in the garden. With hindsight I could have maidened the Pirat today but flew my tried and tested ASW24 instead.

Re: SZD30 Pirat

Posted: 24 Mar 2019, 22:33
by wookman
Nicely done Rick.