Thanks, though.

Ed, I don’t suppose you copied the 6127 before running for it?

Agreed, but reaching for another pint in the virtual pub, re. 1) it was considered that the part inboard of, say, 40% didn’t really do anything useful anyway, so that rule was only loosely applied, at least by De Havilland for a while. Maybe this was because they were initially just copying US designs as per the Flight article in the other blade thread, and the Americans only really had radials apart from the Allison. (Spit I is an example, with plenty of shank outside the cowl radius):
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(2) Aerofoils were compared, and some optimums were arrived at, but see 4, (3) You’d think so, wouldn’t you? But (4) it isn’t just the extremes of performance. History is littered with aircraft that suddenly got a whole lot better, or worse, with a change of prop. Almost always glossed over by that aircraft’s ‘experts’. What we have is a part of the drive chain that can vary its efficiency by five, ten percent or more. It is the only means to convert a reciprocating engine’s power to an aeroplane’s motion. If it were, say, a prop shaft that could, if the wrong one was selected, reduce an engine’s efficiency by just 5% then it would be got right – for reasons of economy if nothing else. But there are all kinds of ‘it’ll do’ arrangements flying, and the work done eighty years ago is largely unknown or ignored. I suppose its fair to say that in a military aircraft with reserves of power an inefficient prop is not a safety issue in normal civilian usage, so it happens. (which reading it back is what you said) (5) I need a CAD orientated volunteer!

Here you go. No one has original dH tables. The new blades for UK Spits with DH props were done by measuring existing ones. That data is jealously guarded.

HOWEVER it can be pieced together – technically for the Spit I de H 55409 blade, but I suspect it’s the same. In these graphs you need propeller ‘III’ in the first two figures, and propeller ‘V’ in the last. All you now need is an absolute measurement of chord at 0.7 radius, something that frustratingly I can’t put my hands on right now. From Fig 4 you can work out the chord along the blade (the figures are ratio of chord to chord at 0.7r). From fig 2, thickness to chord, you can derive the thickness. Angular twist (fig 3) is fairly straightforward. These are from RAE Reports 2357 and 2602, available online.

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Blade planforms were not symmetrical of course, they were plotted along a straight axis defined by centre of mass of the section. That’ll require some work, but is doable – or you can just do it by eye, from photos, as yours is a replica.

For that key dimension, chord at 0.7r, I will dig in what I got from Farnborough before they released the lions.