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Russell Duffy wrote:
What length and diameter do you need exactly?
200 mm M8 studs are an off-the-shelf item, for example. So are
200mm M8 bolts with 101,000 psi rating.
McMaster Carr has a pretty good stock of this sort of thing.
Hi Bill,
The bolts are M10 x 1.0 thread, which seems to be the problem. I took a very quick look at the bolts from the dissected single rotor, and they're about 140mm for the longest, and maybe 135mm for the others. Note, this was not carefully measured, so don't anyone go buying bolts based on this. The only thing I could find at McMaster Carr was full threaded studs, with the description below. It works out to about $8 per stud. I was able to buy one set of custom manufactured bolts recently, and they should be here any day. They were $116, so just about inline with using homemade studs I guess. I have to believe there's a sources for the exact bolts we need, but I haven't been motivated enough to find it yet. Cheers,
Rusty
Anyone care to do the math on the stress on each bolt used to hold a 6.5B together? I'm no engineer but I do know one & he has pointed out that if stresses are well below the danger zone, rolled threads vs. cut threads just ain't that big a deal. (To back that up, he's flown with re-cut prop bolts on wood props for probably more hours than I have total time.)
Remember, factory 13B bolts seem to break with some regularity in high power operation & I assume they are rolled, not cut. To me, that says that conventional wisdom might not be the end-all best measuring stick.
Charlie
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