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Tony Slocombe's 1/4 Scale Slingsby T45 Swallow Glider

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pfcallaghan
Posts: 9
Joined: 27 Jul 2015, 08:39
Location: Cornwall

Tony Slocombe's 1/4 Scale Slingsby T45 Swallow Glider

Post by pfcallaghan »

Does anyone have a plan for Tonys 1/4 Scale T45 please?
I'm looking for the C of G position and an idea of the wing incidence.
At the moment Im working on the C of G being on or about the wing joiner, but any help would be appreciated, especaially a good photo of the plan showing these details.
many thanks

Paul

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Cliff Evans
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Re: Tony Slocombe's 1/4 Scale Slingsby T45 Swallow Glider

Post by Cliff Evans »

Swallow T45 fuscg.jpg
Swallow T45 fus-50.pdf
(8.64 MiB) Downloaded 30 times
https://lasercutsailplanes.co.uk
https://patteaklegliders.co.uk

pfcallaghan
Posts: 9
Joined: 27 Jul 2015, 08:39
Location: Cornwall

Re: Tony Slocombe's 1/4 Scale Slingsby T45 Swallow Glider

Post by pfcallaghan »

Thanks Cliff
Just what I needed.
Paul

pfcallaghan
Posts: 9
Joined: 27 Jul 2015, 08:39
Location: Cornwall

Re: Tony Slocombe's 1/4 Scale Slingsby T45 Swallow Glider

Post by pfcallaghan »

Blimy.. just had a look relative to the glider fus and quite surprised just how far forward it is from the wing joiner!!

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RobbieB
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Re: Tony Slocombe's 1/4 Scale Slingsby T45 Swallow Glider

Post by RobbieB »

Most certainly because of the wing high angle of attack relative to the tail.

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ian davis
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Re: Tony Slocombe's 1/4 Scale Slingsby T45 Swallow Glider

Post by ian davis »

Robbie I've never heard of the A of A being part of any C of G determination. If I've misunderstood I'll get back in my box.

Ian ;)

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RobbieB
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Re: Tony Slocombe's 1/4 Scale Slingsby T45 Swallow Glider

Post by RobbieB »

Ian,

Main wing incidence, CG and tailplane incidence are all intimately connected. Change any one, then for continued level flight you must change at least one of the others.

Assuming the tailplane and the elevator are flying at zero incidence (the theoretical ideal) then increasing the main wing incidence will require a forward shift in the CG if you are to return the tail to zero incidence without the assistance of negative elevator trim which is less than ideal. The ideal tail incidence for a symetrical tailplane (and that includes the elevator, of course) is zero degrees.

All aerofoils have an optimum angle of attack designed into them but we do require them to fly at varying A of As (slower or faster) depending upon the conditions or whatever speed we want to fly at. I personally have my models rigged with the main wing set at a low A of A which facilitates a rearward CG range - but that's just my preference because for me it makes for a much nicer model to fly. Whack the main wing incidence up to three, four degrees or more then you are going to have to move the CG forward to compensate which will give you a very stable model but not a nice one to fly - particularly when circling in thermals.

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