How do you think they made the hinges?

[birdlegs]

Re: How do you think they made the hinges?/strut angles

Mike; I once had a lift strut that looked alot like the one in the picture, it was caused by an outside groundloop............still not too funny after all this time!!!!!!!!!

[crispy critter]

Re: How do you think they made the hinges?

Mike,
It all makes perfect sense to me.I congradulate you for attempting to learn the tricks of the trade.Good luck and have fun with it.I like to weld but I'm not all that great at it,I can do it and sometimes even make it look good(depending what I'm welding.Here is a picture of a one-piece strut fitting that I made...if you can tell much about it.

[mhorowit]

Re: How do you think they made the hinges?

Mike,
It all makes perfect sense to me.I congradulate you for attempting to learn the tricks of the trade.Good luck and have fun with it.I like to weld but I'm not all that great at it,I can do it and sometimes even make it look good(depending what I'm welding.Here is a picture of a one-piece strut fitting that I made...if you can tell much about it.

So tell me... did you discuss it with your A&P prior, then let him inspect the part before mounting? Really. I'm still awed about how readily my A&P accepted that patched landing gear without knowing who did it and what their skill level was; I mean, looking at the repair was one thing, but how did he know the metal hadn't been adversly affected? I'm such an inefficient welder that when I weld a piece, everything within a quarter mile gets hot! - Mike

[Guest]

Re: How do you think they made the hinges?

As I read 43.13, if I have the same metal in sheet, I can form it around the tubing. Is that your reading? - Mike

Mike, I don't see that in the reading of par 4-101 or from fig 4-43. Where do you see it?

If you use a sheet (assuming it was legal) or a stream line tube of the same size like fig 4-43 indicates you have to weld up that seam on the trailing edge. Lots of weld and results in lost of warpage. If you slide a piece of the larger size over there is no trailing edge(te) to weld up and the warpage is easier to control.

I may have some used tubing that will fit for a sleeve if you split the te.

Also have a pile of struts. Many champ, some I forgot but many piper. If you want something to practice on of less value (piper) than t-craft strut (rare hi value) I could cut one and send it to you for shipping charges.

Your strut looks to be repairable. Have an a&p ia look over your shoulder so you can put it back in service when you are done. It's a rare part.

Big problem with repair on a long metal strut is the way the shrinkage the weld puddle causes the strut to "bend". Weld on one side, let it cool, and the tips bow toward you, do the other side, let it cool, then they bend toward that side. Basically you can think of it as welds shrink the metal, after it cools.

When you're done it will probably not be straight. You can straighten it by taking advantage of how hot metal shrinks. Heat a new weld bead on the convex side and let it cool. Re-assess the situation and repeat.

Dave.

[mhorowit]

Re: How do you think they made the hinges?

Mike, I don't see that in the reading of par 4-101 or from fig 4-43. Where do you see it?

I'm looking at para 4-92 and the note in Fig 4.35. Please let me know if I'm using an incorrect reference.

"... warpage... ."

I'm beginning to discover that phenomenan, but haven't begun to attempt to counter it.

I may have some used tubing that will fit for a sleeve if you split the te.

Very generous of you. Let me get a bit more organized; I'll get back to you on that.

Your strut looks to be repairable. Have an a&p ia look over your shoulder so you can put it back in service when you are done. It's a rare part.

Repairable? Maybe I'd better keep my hands off it and find a real welder!

Big problem with repair on a long metal strut is the way the shrinkage the weld puddle causes the strut to "bend". Weld on one side, let it cool, and the tips bow toward you, do the other side, let it cool, then they bend toward that side. Basically you can think of it as welds shrink the metal, after it cools.

When you're done it will probably not be straight. You can straighten it by taking advantage of how hot metal shrinks. Heat a new weld bead on the convex side and let it cool. Re-assess the situation and repeat.

More to learn

- Mike

[Guest]

Re: How do you think they made the hinges?

I'm looking at para 4-92 and the note in Fig 4.35. Please let me know if I'm using an incorrect reference.

- Mike

Mike, the correct reference is to par 101 "Wing-Brace Struts and..." and fig 4.43. Notice sentance 3 and 4. Round members can be done as you suggest by simple reference to this paragraph.

But 43.13 is a means of obtaining approved data without doing any extra work when it does not conflict with manufacturters instructions. Read the letter before table of contents.

IA's can use approved data but cannot create approved data. So an IA can simply use this data in 43.13 as approved data without much effort. He can stray a little. I have often used 43.13 data and said in the 337 "similar except..." Never had a probem with it but how much one can or will stray varies.

Using par 4.92 for streamlined repairs is in conflict with the statements in 4.101 so I wouldn't stray that far. But if I was convinced using sheet was the best way to do the repair I would submit a feild approval and see if FAA agreed and proceed from there.

But all that was just about paperwork and repair integrity. Both are important. From a practical point of view may have the strongest effect. ie there is not stream line tube availible or there is

Hope this helps, sorry for being long winded!

Dave.

[mhorowit]

Re: How do you think they made the hinges?

Hope this helps, sorry for being long winded!
Dave.

No problem Dave - what you are doing is orientating my thinking to the same direction 43.13 intended, rather than going off on a tangent. Let me read over the section then I can talk intelligently - Mike

[mhorowit]

Re: How do you think they made the hinges?

Mike, you need to purchase a copy of the EAA's book:
"Aircraft Welding"
The ISBN is: 0-940000-49-0

Ooooh, it came in yesterday and I discovered it today (too many piles of stuff). Looks like it will be a long night reading. Thanks for the suggestion. - Mike

[mhorowit]

Re: How do you think they made the hinges?

Mike, the correct reference is to par 101 "Wing-Brace Struts and..." and fig 4.43. Notice sentance 3 and 4. Round members can be done as you suggest by simple reference to this paragraph. Dave.

Dave - I went over the organization of 43.13 and see where I misread. Thanks for pointing it out. - Mike

[mhorowit]

Re: How do you think they made the hinges?

Mike, you need to purchase a copy of the EAA's book:
"Aircraft Welding"
Dick

Dick- did I tell you that was a great read? and neat little projects to make work easier ! I took today off, so I get a 4 day weekend. Today I'll try to straighten and use a welded sleeve on a piece of bent conduit. Also I wanna build that jig on page 27. - Mike

[mhorowit]

Re: How do you think they made the hinges?

Oh, it's a perfectly good question. Hold on tight, I'll try and explain.
About 6 mo. ago I was working the ignition noise problem, and after determining the short shielded plug wouldn't work, I dug up my plans for building 'cans' for them. That involved some welding (which I had done in college, but that was 30 years ago). I mentioned to a friend that I was thinking of renting an Ox/Ac rig and learning to weld and he offered me his 'on indefinite loan'. So I started to relearn the skill. At some point I figured I ought to make this interesting so I cut a fishmouth joint (after buying an angle grinder) and joined two pieces of EMT in a 'T' joint. It looked ok, so I figured I'd think up a project that did a lot of things I'd like to do. Found the b'prints on the website (my copy of the CDs came in today) and looked for something fun to build. A simple version of the horizontal stab. didn't look too difficult, and after I teach myself how to do the bending, I"ll cover it. [...]

So, I'll figure how to bend EMT so that the tubing lies in the same plane, cut several different angles of fishmouth joints (using WinMitre to make templates) and build something that looks like a horizontal stab. only not anywhere to specs.

Also, I'll probably never touch a real airplane with a torch, but I could build a part that attaches to the airplane. That's where the duel brake strap-on came in.

So that's where I am at the moment. How did you like the ride so far? - Mike

PS. Gotta do something until I find another Tcraft!!

And here is where we stand on the project - Mike

[Guest]

Re: How do you think they made the hinges?

And here is where we stand on the project - Mike

Looks good Mike. So what do you think?

Is it painfully annoying to weld or fun?

My opinion seesm to alternate back and forth.

I keep buying more welding machines, can't tell whether that's cause fun or if I have to prevail.

Dave.

[Dick Smith]

Re: Welding/repairing 4130

Mike, try to open this link and select the clip regarding working with 4130 chromoly. Select a show...via scrolldown to the topic regarding 4130.

http://www.supercubproject.com/theater/

Dick

[mhorowit]

Re: How do you think they made the hinges?

Looks good Mike. So what do you think?

Is it painfully annoying to weld or fun?
Dave.

I love it. Built a neat jig from the EAA welding book; I'll post a picture of it in a day or so.

Next task is to follow the RAy Stits video and cover it in two halves. - Mike

[high time cub]

Re: How do you think they made the hinges?

[QUOTE=mhorowit]I love it.

Keep this tradition (of craftsmanship) in mind while you weld.....

http://www.pantheon.org/articles/v/vulcan.html