Getting the correct size innner sleeve by cutting and welding.

[mhorowit]

Some time ago, I was practicing splices using an inner sleeve, and I was fabricating the inner sleeve by cutting a slot out of outer sleeve material, refoming it, and welding it closed. At least one person opined that was not allowed.

Now enters Figure 4-44 of AC 43.13. This is an illustration of a streamline tube splice using a split insert. It shows a piece of outer tubing being split at the trailing edge and re-welded to get the desired dimension for an inner sleeve.

If Figure 4-44 shows that splitting and rewelding is OK with streamlined tubing, why would anyone say it's not OK for round tubing? - Mike

[jCandlish]

Re: Getting the correct size innner sleeve by cutting and welding.

Round tubing is manufactured seamless. Streamline tubing is a weldment.

[Guest]

Re: Getting the correct size innner sleeve by cutting and welding.

I think that streamline tube is also formed from round tube by drawing it over a over a mandrel. UNIVAIR will hopefully comment. Dave

[flybikefarm]

Re: Getting the correct size innner sleeve by cutting and welding.

It's all drawn from round tube right here in good old Streator,Il. at Plymouth tube. A guy ran a machine shop out of one of my buildings here, made repair parts for the hundred year old draw tables or so they seemed. George

[mhorowit]

Re: Getting the correct size innner sleeve by cutting and welding.

It's all drawn from round tube right here in good old Streator,Il. at Plymouth tube. A guy ran a machine shop out of one of my buildings here, made repair parts for the hundred year old draw tables or so they seemed. George

would one expect they'd have the streamlined tubing we're discussing? - Mike (holding breath)

[Hank Jarrett]

Re: Getting the correct size innner sleeve by cutting and welding.

It's actually made by pulling round tube between two custom turned rollers that progressively flatten the the tube to the shape of the rollers. The tension as the metal is pulled through keeps the tube straight (pretty much, if you do it right) and the rollers need to be adjusted properly to get exactly the shape you want. One of the reasons tubes keep changing size and shape is the rollers wear out, but can be re-cut to a slightly different shape (the rollers are EXPENSIVE!)
There is a gentleman in Schorndorf Germany named Achim Engles who is building Fokker replicas. He has actually has gone to the trouble of re-inventing the processes and cutting dies to make exact replacements for the tubes used in WW-I. IMPRESSIVE. He is crazier than I ever could be, and having a lot more fun. Check out Fokker-Team-Schorndorf. Great guy and a true artist.
Hank

[jCandlish]

Re: Getting the correct size innner sleeve by cutting and welding.

(the rollers are EXPENSIVE!)

So streamline tubing with a seam is the cheap kind? I've seen quite a bit of it, but I cant remember seeing the lot # inked on.

[Guest]

Re: Getting the correct size innner sleeve by cutting and welding.

It's actually made by pulling round tube between two custom turned rollers that progressively flatten the the tube to the shape of the rollers. The tension as the metal is pulled through keeps the tube straight (pretty much, if you do it right) and the rollers need to be adjusted properly to get exactly the shape you want. One of the reasons tubes keep changing size and shape is the rollers wear out, but can be re-cut to a slightly different shape (the rollers are EXPENSIVE!)
There is a gentleman in Schorndorf Germany named Achim Engles who is building Fokker replicas. He has actually has gone to the trouble of re-inventing the processes and cutting dies to make exact replacements for the tubes used in WW-I. IMPRESSIVE. He is crazier than I ever could be, and having a lot more fun. Check out Fokker-Team-Schorndorf. Great guy and a true artist.
Hank

That makes a lot more sense than pulling a mandrel thru it. I must have misunderstood the original descriptiom that I heard.