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Pietenpol-List: center brace wire ftg.
Posted: Fri Apr 19, 2002 10:45 pm
by matronics
Original Posted By: "Gary McNeel, Jr."
I've looked in the archives and found no conclusive answer. Is .080 5/8in. 4130 strip steel stong enough for the center brace wire fittings? Iknow the plans call for 13 ga. which is about .10 thickness, but wasn'tthat in a weaker type steel than 4130? The thickest 5/8 in. 4130 thatAircraftspruce offers is .080. Mark McKellar________________________________________________________________________________Date: Sat, 20 Apr 2002 07:57:55 -0500
Re: Pietenpol-List: center brace wire ftg.
Posted: Sun Apr 21, 2002 7:21 pm
by matronics
Original Posted By: "Mark"
----- Original Message -----
RE: Pietenpol-List: center brace wire ftg.
Posted: Sun Apr 21, 2002 8:17 pm
by matronics
Original Posted By: "Mark"
Mark, even though the plans call for the fittings to be 5/8", I made mine3/4". If there is a serious fault with BHP's originial design, it is thathe universally made his fittings too small. General aircraft designpractice calls for the edge distance from the cetner of a hole to the edgeof the part to typically be twice the hole diameter. That means a fittingwith a 3/16" hole should be 3/4" wide (2 x 3/16" = 3/8" on either side ofthe hole). BHP's fittings are all a little on the short side too - seeMike Cuy's video. I wish I had made all my fittings longer than the planscall for. I didn't on the first fittings I did, and they are all too tightand difficult to get bolts into. As far as using 5/8" x 0.080 4130, it is probably strong enough from atensile strength standpoint, since the 3/32" bracing wire cable is only goodfor about 920 lbs. However, with such thin, narrow fittings you must beextra careful to have absolutely no scratches or dings that can cause stressconcentrations since there is very little margin. If you want to make them5/8" wide, I'd buy 3/4" wide .090 and cut it down, or better yet, just makeit .090 x 3/4".Jack Phillips -----Original Message----->> I've looked in the archives and found no conclusive answer. Is .080 5/8> in. 4130 strip steel stong enough for the center brace wire fittings? I> know the plans call for 13 ga. which is about .10 thickness, but wasn't> that in a weaker type steel than 4130? The thickest 5/8 in. 4130 that> Aircraftspruce offers is .080. Mark McKellar>>________________________________________________________________________________
Re: Pietenpol-List: center brace wire ftg.
Posted: Sun Apr 21, 2002 10:51 pm
by matronics
Original Posted By: "Jack Phillips"
Thanks Jack,That's what I'm gonna do. Mark----- Original Message -----
RE: Pietenpol-List: center brace wire ftg.
Posted: Mon Apr 22, 2002 7:31 pm
by matronics
Original Posted By: "Steven G. Isaacs, MD"