FW: KR> KR2 ARTICLE-KITPLANES NOV 2010
Geez, it comes down to this; does one single bolt and spacer weigh less than two?!! >
FW: KR> KR2 ARTICLE-KITPLANES NOV 2010
Where is all this stuff coming from? I got plans for a KR-1 in the mid seventies and have never herd of a wing failer on a KR> Jim - Original Message From: Glenn Martin <rep...@martekmississippi.com> To: KRnet <kr...@mylist.net> Sent: Sat, October 2, 2010 9:49:57 PM Subject: Re: FW: KR> KR2 ARTICLE-KITPLANES NOV 2010 John Martindale wrote: > A long time ago before "experimental" came along (like in the 1980s), the > Australian authorities did mandate a change to the bolt arrangement that > specified a spacer tube between each pair of WAFs and a longer single > through bolt instead of two short independent bolts. > > I think this reflects a better engineering solution with respect to shear > forces I can see how a thicker bolt could improve shear strength, or a bolt of a greater rating, but unless I am missing something, I see no way that a longer bolt of the same type and size could improve its shear strength at the wing attach fitting junction through an increase in its length. Did I miss somthing in physics class? -- Glenn Martin (N5PQ) Martek Mississippi Electronic Repair 13238 Hudson-Krohn Rd. Biloxi, MS, 39532 rep...@martekmississippi.com ___ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
FW: KR> KR2 ARTICLE-KITPLANES NOV 2010
Hi Glenn Yeh. I think you did but I don't just what :-) I'm pretty sure a bolt in double shear apparently is proportionately stronger than two single ones in single shear of the same dia. I presume the Australian authorities knew what they were on about when they insisted on thisbut then again I'm known for my dislike of the buggers. John Martindale 29 Jane Circuit Toormina NSW 2452 AUSTRALIA ph: 61 2 6658 4767 mobile: 0403 432179 email: john_martind...@bigpond.com snipDid I miss somthing in physics class? -- Glenn Martin (N5PQ) Martek Mississippi Electronic Repair 13238 Hudson-Krohn Rd. Biloxi, MS, 39532 rep...@martekmississippi.com ___ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.856 / Virus Database: 271.1.1/3173 - Release Date: 10/03/10 05:05:00
FW: KR> KR2 ARTICLE-KITPLANES NOV 2010
Pete wrote: >It's the addition of the tube spacer that adds the strength not the > length of the bolt. What it effectively does is take an area that has > two potential failure modes and replaces it with one. > Cheers. > O k..but that is not SHEAR STRENGTH we're talking about, and I cant see any improvement in the Tensile Strength either. Common sense seems to indicate that if one bolt fails in a single bolt structure, the results would likely be more catastrophic than if one bolt fails in a two bolt system. It does not make sense to me. That being said, what are these "Failure Modes"you are referring to? -- Glenn Martin (N5PQ) Martek Mississippi Electronic Repair 13238 Hudson-Krohn Rd. Biloxi, MS, 39532 rep...@martekmississippi.com
FW: KR> KR2 ARTICLE-KITPLANES NOV 2010
It's the addition of the tube spacer that adds the strength not the length of the bolt. What it effectively does is take an area that has two potential failure modes and replaces it with one. Cheers. Peter Bancks. Ballina, Oz. On 3/10/2010 12:49, Glenn Martin wrote: > I can see how a thicker bolt could improve shear strength, or a bolt of > a greater rating, but unless I am missing something, I see no way that a > longer bolt of the same type and size could improve its shear strength > at the wing attach fitting junction through an increase in its length. > Did I miss somthing in physics class?
FW: KR> KR2 ARTICLE-KITPLANES NOV 2010
John Martindale wrote: > A long time ago before "experimental" came along (like in the 1980s), the > Australian authorities did mandate a change to the bolt arrangement that > specified a spacer tube between each pair of WAFs and a longer single > through bolt instead of two short independent bolts. > > I think this reflects a better engineering solution with respect to shear > forces I can see how a thicker bolt could improve shear strength, or a bolt of a greater rating, but unless I am missing something, I see no way that a longer bolt of the same type and size could improve its shear strength at the wing attach fitting junction through an increase in its length. Did I miss somthing in physics class? -- Glenn Martin (N5PQ) Martek Mississippi Electronic Repair 13238 Hudson-Krohn Rd. Biloxi, MS, 39532 rep...@martekmississippi.com
FW: KR> KR2 ARTICLE-KITPLANES NOV 2010
Hi Mark A long time ago before "experimental" came along (like in the 1980s), the Australian authorities did mandate a change to the bolt arrangement that specified a spacer tube between each pair of WAFs and a longer single through bolt instead of two short independent bolts. I think this reflects a better engineering solution with respect to shear forces but having said that there were no instances of any failures at the time and I know of none since under the original RR arrangement. The Aussie authorities mandated a number of things back then that are now superceded by experience or supply (like glues and Dynon cloth) but several remain valid, eg., flight in the rear 2" of CoG envelope. John Martindale 29 Jane Circuit Toormina NSW 2452 AUSTRALIA ph: 61 2 6658 4767 mobile: 0403 432179 email: john_martind...@bigpond.com -Original Message- From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf Of Mark Langford Sent: Friday, 1 October 2010 3:54 AM To: KRnet Subject: Re: KR> KR2 ARTICLE-KITPLANES NOV 2010 I met Bob Grimstead while in Perth. He's a nice guy, likes to write "flight test" articles for Aussie and US magazines, but apparently he's not qualified to speak to the integrity of the KR wing attach system. The Aussies have dictated a couple of changes to KRs built and flown there, but "improving" the WAFs isn't one of them, as far as I know. ..snip.
