Re: Pietenpol-List: Re: spar butt straps
Posted: Sun May 02, 2010 6:16 am
Original Posted By: Ken Chambers
#yiv1659257443 .hmmessage P {PADDING-BOTTOM:0px;MARGIN:0px;PADDING-LEFT:0px;PADDING-RIGHT:0px;PADDING-TOP:0px;}#yiv1659257443 .hmmessage {FONT-FAMILY:Verdana;FONT-SIZE:10pt;}One question, are you going to bolt to the fuselage fittings-through the cabane itself?If so then why do you want anything in there? The only way an insert is going to addstrength in tension is if that insert has at least one more bolt through it and the strutan inch or so above the bottom hole. This is a good idea with aluminum. In this caseit's best to use a bar of aluminum.-It's not like using wood struts. What you do there is add metal plates to the outsidewith another bolt 1 1/2" above the one that bolts the strut to the fuselage. Thisicreases the area of the "plug" sides thus increasing the tearout resistance dramaticaly.-In both cases the idea is to strengthen the strut.-ClifThere is only about 5/16" of material below-the bolt hole on the bottom fitting (and above on the top fitting). With the loads and shock loads applied-by the strut the bolt would pull out the small chunk of wood below the bolt along the grain lines.- You would be much better off with-metal inserts.-- Ed G.-----> > I believe I have my posting woes fixed, so I am trying this again.> > I am using aluminum cabanes and am curious if a hard wood, (oak/ash) would be suitable for the inserts. I know most use some type of steel or aluminum, but since the fittings attach to soft spruce and ply wood gussets on the fuselage end, why not wood inside the cabanes?________________________________________________________________________________Date: Mon, 3 May 2010 10:06:08 -0500Subject: Re: Pietenpol-List: Re: spar butt straps
#yiv1659257443 .hmmessage P {PADDING-BOTTOM:0px;MARGIN:0px;PADDING-LEFT:0px;PADDING-RIGHT:0px;PADDING-TOP:0px;}#yiv1659257443 .hmmessage {FONT-FAMILY:Verdana;FONT-SIZE:10pt;}One question, are you going to bolt to the fuselage fittings-through the cabane itself?If so then why do you want anything in there? The only way an insert is going to addstrength in tension is if that insert has at least one more bolt through it and the strutan inch or so above the bottom hole. This is a good idea with aluminum. In this caseit's best to use a bar of aluminum.-It's not like using wood struts. What you do there is add metal plates to the outsidewith another bolt 1 1/2" above the one that bolts the strut to the fuselage. Thisicreases the area of the "plug" sides thus increasing the tearout resistance dramaticaly.-In both cases the idea is to strengthen the strut.-ClifThere is only about 5/16" of material below-the bolt hole on the bottom fitting (and above on the top fitting). With the loads and shock loads applied-by the strut the bolt would pull out the small chunk of wood below the bolt along the grain lines.- You would be much better off with-metal inserts.-- Ed G.-----> > I believe I have my posting woes fixed, so I am trying this again.> > I am using aluminum cabanes and am curious if a hard wood, (oak/ash) would be suitable for the inserts. I know most use some type of steel or aluminum, but since the fittings attach to soft spruce and ply wood gussets on the fuselage end, why not wood inside the cabanes?________________________________________________________________________________Date: Mon, 3 May 2010 10:06:08 -0500Subject: Re: Pietenpol-List: Re: spar butt straps