Some rumaging in the prop box uncovered one new in pkg. Graupner Super Nylon 6×6 with the safe limits document in eight languages enclosed. If my math coversion is correct their limit for tip speed works out to 596 ft/sec. The given ‘constant” 3438
is divided by 1/100 of the diam in cm. The example given solves for safe speed for their 28 cm (11.024″) diam. and yields modest 12.28k. Solving for the diameters of my interest yields 22.5k for 6″ & 24.6K for 5.5″ both reasonable as we’ve yet to get into that range with our diesels. We will however be keeping in mind the possible 10 to 15% “unloading”, in flight. Graupner cautions/advises submerging their Super Nylon’s in boiling water “for a short while”, or ” submerging in water at ambient tempertures for acouple of days” to insure adequate moisture content!
Now if we could only uncover similar data for Grish Tornado & for Cox!
Cheers;d-d