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Re: Recreating the Irvine Pixie S/C or intermediate glider
Posted: 18 Jul 2018, 20:33
by Igull
PaulJ wrote: 17 Jul 2018, 22:24
FWIW I was chatting to another well known producer of laser cut kits and he told me that he paid £3,000 EACH for the copyright to six of the designs he produces.......

. The designer in question lives in the USA but it kinda explains why some of these kits cost as much as they do....... and you have to wonder how Outerzone gets away with making so many designs so readily available
There's not a hope in 'H' that I would ever give 'R----X' a single penny of my hard earned - not after the shoddy way I was treated

)
I'm not sure how outerzone do it, I just make sure they get a decent donation occasionally (which reminds me).
Without the likes of outerzone and the good folks that supply plans/mags/books etc our hobby would be the poorer.
Cheers
Neil
Re: Recreating the Irvine Pixie S/C or intermediate glider
Posted: 18 Jul 2018, 20:39
by Igull
No no no

but I do like 'Pixie Dust' !
And here was me thinking that you were quite egotistical
I cant get a good shot of the section as the tips being angled spoil the profile:
The max thickness is fairly forward and its exactly an inch thick.
The centre sheeting is let in. The fus sides are 3/32 not 1/16 as I said last night, with
doublers under the wing seat but (curiously) none in the nose.
Yes 'generic' flat-bottom clark-Y, from french curves or a shoe sole
Yes, it's an oddball thing, I'm struggling to get any kind of decent tangent to the leading edge because the CP is so far forward and the LE is 9.5mm sq. I think you need to take a razor saw to your wing and just send me up a rib
I WOULD like to keep it as close to the original as poss 'though, contary to popular opinion it seems - maybe RG15 and glasscloth is the answer
Cheers
Neil
Re: Recreating the Irvine Pixie S/C or intermediate glider
Posted: 18 Jul 2018, 20:49
by Igull
Incidences, I make it 1.4° overall measured to the flat-bottoms.
These two screens are of the same photo taken at about 15' away:
OK, that's good, let's go for 1.5deg on the wing and 0.0deg on the tail then and round it up.
I would suggest changing the tips to a clark-Y shape, for one thing they are very a characteristic feature of the 'Pixie' design wrt copyright, and they're the only part of the design I dont like, they're ugly. But the main reason is that you cant stand the wing against a wall, it always falls as its standing on the T/E !
I don't have a prob with that, but it wouldn't be a pixie? If copyright is an issue, then they'd be struggling to defend the original design as it stands - I mean, look at all the designs we have - it could just as easily be a Peacemaker c/l wing tip !
I take your point about the wing tips though - but maybe you should be storing them horizontally
Making it a different size or
slightly different shape is sufficient. The fact that there isn't an accurate plan and that we are changing the name is enough IMHO?
Cheers
Neil
Re: Recreating the Irvine Pixie S/C or intermediate glider
Posted: 18 Jul 2018, 20:58
by Igull
The sum of the IQ's (and probably ages

) devoting thought to this "recreation" has to at least exceed the likely Reynolds Numbers
Now just a minute here, I only
look old ! And I'm at least less than half the sum of Phil and Shaun's ages

And who's this Reynold's bloke anyway, is he on this forum - does he even own a s/c tx - his posts are probably a load of hot air and viscous forces within the boundary layer anyway

Re: Recreating the Irvine Pixie S/C or intermediate glider
Posted: 19 Jul 2018, 10:09
by Wayne_H
Igull wrote: 18 Jul 2018, 20:58
............... his posts are probably a load of hot air and viscous forces within the boundary layer anyway
Careful young Pixiewalker, he now lurks in the Turbulent Zone (since Jedi Paul banished im there

) and the Force in im be strong me thinks....

Re: Recreating the Irvine Pixie S/C or intermediate glider
Posted: 19 Jul 2018, 11:46
by Igull
Phil_G wrote: 18 Jul 2018, 21:30
Re the ribs, I wonder if I can find enough 'things' to make a profile thingy, you know what I mean?
Or maybe cover it in clingfilm then mould some papier-mache or rope-soaked-in-araldite round it?
or a worm of car body filler paste? Or Chloe might have some clay...
We only need the top and the L/E profile... I'll see what I can find.
Like the JML profile gauge of the 1970's

TBH, a bit of cornflakes packet neatly trimmed to the profile then scanned is fine by me.
My problem with drawing the section is that I can't get a decent section using a 3/8" formed LE (which has it's own shape of course), a high point at 51mm from the LE, and a 19x5mm TE - chord being 190mm total. The high point at 51mm looks strange - although the pix don't lie. There is one of the pix that shows a perfect set of ribs all neatly fitting a smooth curve to all the components. I do this nonsense nearly every day and it's really the first time I've come across an issue

It's good to be picky though
Cheers
Neil
Re: Recreating the Irvine Pixie S/C or intermediate glider
Posted: 19 Jul 2018, 13:32
by PaulJ
What is the importance of 3/8 pre-formed LE? Can't the builder just use a strip of 3/8 x 1/2 or cut a strip of whatever width off a 3/8 sheet and then shape it to fit your ribs????? That's what I normally do anyway.......
Paul
Re: Recreating the Irvine Pixie S/C or intermediate glider
Posted: 19 Jul 2018, 13:43
by Igull
PaulJ wrote: 19 Jul 2018, 13:32
What is the importance of 3/8 pre-formed LE? Can't the builder just use a strip of 3/8 x 1/2 or cut a strip of whatever width off a 3/8 sheet and then shape it to fit your ribs????? That's what I normally do anyway.......
In the grand scheme of things, it's completely unimportant, but being a true to scale model, each rivet must be counted

That's exactly what I do too - although I happen to have the correct preformed items in front of me as I type - supposedly 3/8", but actually 9.5mm high x 8mm wide or 3/8" x 5/16" in old money (which is probably when I bought them too

)
I'm just trying to get it the same for now - I could put any old section on it and it would be just fine (better even). I'm just trying to find how it can possibly be with the dimensions given - pedantic even.
Re: Recreating the Irvine Pixie S/C or intermediate glider
Posted: 19 Jul 2018, 14:17
by Igull
I just spent some time after lunch while supposedly cutting grass Paul
The LE has to have been 3/8 x 1/2 high not 3/8 sq - that works just fine. I don't have any preformed sections to measure, but a but of rect strip cut from a sheet is perfectly ok. That way all the silly spar positions and section thickness fits in OK and I can get something that sort of resembles a real section. Pic attached for the anally interested
Phil, you can print the pic and do a blue peter cutout to see if that fits OK
Cheers
Neil
Re: Recreating the Irvine Pixie S/C or intermediate glider
Posted: 19 Jul 2018, 15:05
by GarydNB
I'm going with this section. 25mm looks too deep to me, I'm using 20mm depth at spars, 3/8th" sq.L/E. ..3/4"×3/16" ish. T/E and 1/4" × 1/8" spars, spruce in the centre panel and balsa in the tips.
Gary