Posted by Roderick Jenkins on 15/03/2018 12:15:30:
Presumably Mick's prop needs a hub big enough to use several studs on a PCD rather than a single hole through the middle.
Regarding suitable woods; it is, perhaps, worth bearing in mind that American oak, walnut and maple are all different species with different properties to those grown in the UK. Similarly "mahogany" covers an enormous variety of similar looking but otherwise unrelated species – There are no EN numbers in the timber trade!
Cheers,
Rod
Definitely agree, and although this prop is not going to propel a piloted aircraft, then the timber should still be selected with regard to grain slope, knots, pitch pockets, shakes and so on before the wood is laminated so as to be reasonably sure that the completed item stays together. The glue should be of a high standard standard, prefereably something like Aerodux or an epoxy and not any old pva or old bone glue as a 1/5 scale rotary will still be able to generate a respectable level power and torque. A disintegrating 28" prop would be rather dangerous.
Is your engine the Blackmore Bentley BR2 mick ?
Trevor