ORIGINAL: Coke
Bob I have to say I have have not done the modification nor would I consider so doing, as I said in my post there's something amiss with the propellers and they should be consigned to the rubbish bin. Not only this if I read your post correctly you then go on to advocate overtightening of the propfixing(s) to alleviate the said problem. From all my time in engineering one should never cure one problem by creating reasons for another possible one with possibly a worse outcome. I too am not looking to pick a fight whatsoever but if I come across such a prop it goes in the bin or is used to light the fire or stir paint
It's interesting to note that you (like myself) have an engineering background and we concur on the risks involved in this process.
Aerobob, do you have an engineering background?
What we're talking about here is not a "certain failure" but a significant increase in the risk of failure. When we're talking about something with not insignificant mass, spinning at 7K+ RPMs within "striking" distance of bystanders, I don't think it's advisable to increase the risks any more than is absolutely necessary.
Hospital care (and law suits) are very expensive compared to buying a prop that isn't so soft that you need to mess around like this.