. So tere I am, my usual lovable self, pissing & moaning about all these HOT projects that I've been pissing & moaning about for the last couple of years, NOW using a simple case of cancer as my excuse for not getting anything done... and one of my regular cage-rattlers sez: 'So what ARE these hot projects? Is there anything on them that WE could work on?' Which brings me down a notch or two in a hurry. Calling my hand. Well... okay.
QUANTIFIED TEST DATA vs COMPARATIVE TEST DATA
...and hit the wrong damned key!
Great way to start, eh?
Okay, the subject is Quantitative Data versus a WAG, which stands for a Wild Assed Guess and it goes something like this: Bracket for... something. It's busted and your mission, should you care to accept it, is to make a REPLACEMENT that is both stronger AND lighter.
First thing you gotta do is get all the pieces outta the old airframe so you can figure out the SIZE of the thing, which you do. It is
4-5/8 by 8-3/8 and is made of Mystery Metal because there's no markings.Miking it, you get ABOUT 1/16" It has been jitterbugged on both sides, etched & Alodined; 3/4" flange along the narrow dimension on one end, which has four holes for 1/8" fasteners. It supported the power supply for a high-intensity strobe beacon, which it did via four
8-32 nut-plates, flush-riveted. Not interested in those dimensions at the moment, just the maximum strength. Fracture was along the bend for the flange and there's some evidence the thing was already starting to fracture before the tail-first landing finished the job.So... how strong was it to begin with? One way to find out is to fabricate an identical piece, rig a bracket to simulate the load of the power supply (which weighed about 10 ounces) then rig a bridal from the bracket to your bucket of lead and see what it will take. As a starting point, the bird was spec''d for +6 & -4. The original load was 10.8ounces so 6x10.8 gives me 64.8 oz or about four pounds.
Rig a vertical piece I can hold in the bench-vise. Take the part I've fabricated out of .062 T2024-T3, weigh it on the gram scale, writ the weight on the back then rivet it to the upright using 1/8" rivets. Bracket & wire to the lead bucket gets measured and added to the static load. Pour in four pounds of lead, consisting of chunks of wheel weights, some lead sinkers, .44" lead balls for a pistol, ditto for some .54 loads for a real shooter, couple of lead bb's... to get precisely 4.1 lbs.
Nothing happens. Keep pouring in the lead. Somewhere up around 24 lbs... call it 35g's... wife asks me if I want some coffee and I say, Hell yeah! and leave the thing to hang. It's still hanging there a couple of days later when I need the vise for something else. I put away the lead, dismantle the bridal and toss the upright (with the bracket still attached) under the bench. this was back in March... mebbe February... somewhere back in there. ( But instead of getting back to this project I end up getting diagnosed with Cancer. But that's a different topic)
So.... the hot project is to come up with a bracket that weighs less but exceeds the required spec.
This is a simple chore. Trouble is, I can no longer bend at the waist, nor can I pick up 25 lbs of lead -- I can't even empty the bucket other than a handful at a time and I figure I got better things to do... but this one will come in handy if I need an excuse for NOT doing something somebody wants me to do, such, as making up a bracket... you get the idea.
Lotsa observations not otherwise posted: The bracket was sheared. There was no sign of dressing; edges were kinda rough, which is why it was PROBABLY starting to crack even before the tail-wheel landing. I'm told the thing was part of a kit but the guy doing the telling couldn't say if the bracket was part of the kit or if it was made-up by the fellow fellow who installed it... except he didn't. The installation was done by some 'Working Under Supervision' wet-back and then signed-off by the guy who got all the lolly.. and who doesn't want to talk about the job, his work ethics or why the sky is blu. The bird has already been fixed and flown home... so this real hot project isn't hot at all, except to me.
-R.S.Hoover
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