Driven from this forum indeed...however now puzzled Wife is getting emails notifying posts on this forum, must be a glitch in our Outlook setup, so have had to add it to her spam filter as well as mine, as there's no means of unsubscribing.
One contributor wrote of his 'successful career in power transmission', mine's in structures, been a good money-spinner if that's how you measure success...generally use software nowadays which can make you lazy on hand calculations. Did check moments when drawing up my redrive, but discarded the design notes five years or more ago when the numbers got so high it was pointless. This isn't stressed-skin analysis but a chunk of 16mm aircraft alloy plate with a block bolted on and a 37mm eccentric shaft clamped in it, only 'hole dug' for myself is the one that bust the propeller after crash-landing and somersault in marshy ground, the redrive shrugged it off and was unharmed and reused, so building a bit of extra beef came in handy? ;-)
When designing for moments and similar it is often cheaper in man-hours to just up the section, inspecting Engineers sometimes justify their fees, play to the audience or just plain like to watch you jump hoops, material is cheap and time isn't, so provided your ego can handle the odd smug comment of 'I made them increase the section' you go heavier, finish the job, pocket the money and stroll away...
However on this occasion the critics aren't being paid, but appear to ganging up on the maker, sensing weakness and in the process potentially wrecking a useful facility making custom redrives, so I did them again:-
Side load capacity on the reduction at the propeller flange face = 28,328.5N, 2,888.703Kgf or 6,368.5 pounds, which is 2.84 imperial tons
Dynamic bearing capacity is 29,600N, 3,018.36 Kgf or 6,654 pounds, this is 2.97 imperial tons, not a bad match of capabilities eh?
Moment capacity at propeller flange is 3,121.8Nm or 2,302.518 foot-pounds; as such forces are momentary rather than applied whole life, bearings wont be troubled. If you can hang just over one ton off the tip of a foot-long bar protruding from the centre of your propeller shaft without hurting the engine mounts, excellent. 4G loads at 1.5 factor in the UK design code means a 100 kilo motor exerts 0.6 tonne on its mounts. Our code mandates 15G forward crash load too but that's axial and won't bother the redrive.
If you can be bothered with formulae, there's an interesting January 2017 paper on this subject, note the worked example numbers at the end, page 550, which are for a 210hp motor; since real world in homebuilt machinery is under 100hp the numbers tie up rather well, even for the doubled figures for aerobatic forces just before the conclusion.
http://www.arpnjournals.org/jeas/research_papers/rp_2017/jeas_0117_5652.pdf
Bye bye and fly safe, been interesting
K Armstrong