HS710 trimming

[CPSONE]

Anyone out there trim a whole lot less than what the plans say on the taperred ends of HS710 and HS714. Looks to me that there's no reason to taper the inside ends but only the outside to avoid interference with the HS skins and of course de-burr radius etc. Seems like it would add strength to a structurally critical part by not trimming so much. I just want to make sure it's not going to interfere with anything later on in the build.

 

[bkthomps]

Anyone out there trim a whole lot less than what the plans say on the taperred ends of HS710 and HS714. Looks to me that there's no reason to taper the inside ends but only the outside to avoid interference with the HS skins and of course de-burr radius etc. Seems like it would add strength to a structurally critical part by not trimming so much. I just want to make sure it's not going to interfere with anything later on in the build.

the way i understand it you don't have to taper it at all if you don't want to, it is pure weight savings and the extra integrity isn't needed if the plane is flown within it's published limits.....

having said that, i tapered it

 

[roee]

Bad idea

Mike,

Yes, these are structurally critical parts. But there's no reason to believe that these parts are a weak point in the airframe. And in any case, there's no reason to believe that not tapering them as shown on the plans would add strength in any meaningful way that would benefit overall structural integrity.

You've stumbled on a common pitfall that you should learn to avoid. Beware, in general, that going down that path -- arbitrarily adding material to "strengthen" arbitrary parts -- will lead to an unnecessarily heavy airplane that is no "stronger" than stock. And in some cases (though not likely this case) can even have more serious unintended effects, like making a structure too rigid and thereby transferring loads to other structures that weren't meant to carry those loads, etc., thereby actually compromising the structural integrity of the airframe. Anyhow, bottom line, just not a good idea in general.

-Roee

 

[bkthomps]

plus more weight that far aft.....well, is not good, you want as little as possible back there!