billet how can you tell?

[aviator41]

Castings are odd creatures. They are fine in some areas but since they won't take anodizing they can be troublesome to use. good for low stress situations and one-off prototyping using sand moulds. they have their place for sure! Most of the alum. bullet molds you find are cast or extruded billet thats machined. Nothing wrong with them in the world!

Cheers!

 

[HiredHand]

When FN started producing the BHP in 40 S&W they switched to a cast frame because the forged frames were warping and cracking in just a few thousand rounds.

 

[aviator41]

That is mostly a marketing gimmick.

Agreed. "Aircraft grade" is meaningless to those in the industry. don't think I ever saw the term used in any of my books.

 

[aviator41]

When FN started producing the BHP in 40 S&W they switched to a cast frame because the forged frames were warping and cracking in just a few thousand rounds.

There is also speculation that this move was less about making the frame stronger and more about lowering production costs. I have never been able to verify an actual case in which a frame failed outside of the over-proofed test loads that were used by FN in the MkII. It has also been speculated that the quality control of the forgings was below their standards and really offered no significant or appreciable increase in performance over the less expensive cast frame.

Personally, I think the cast frames are less 'refined' looking than their earlier forged counterparts, but thats just me.

 

[AllOut]

I cant imagine any environment more harsh than one found in a turbojet - especially one that is afterburning. Maybe the Apollo Engines.

I can think of one...
Bottom of an off shore oil well! You should see the valves we have to redress after they pull them out. The most heat and corrosive resistant metals in the world eat'n and corroded behind repair/belief in a short time. And STINK! Holy hell they are Nasty!!!
They use Inconel in some turbine/jet engines just we do in our valves.

But as far as buffer tubes go, I don't see how or why anyone would cast them. To fast, easy and simple to machine from a solid bar/billet. If anything, maybe extrude then finish machine.

 

[zodiacflyer]

Compressor IS the cold side is it not? And yes, in the firearms industry "Aviation Grade" is complete BS. I doubt ANY materials in a firearm are tracked from the mine to the finished product and controlled the same way bauxite bound for an aircraft part is. And I have also never heard the words "aircraft grade" used in aviation either, with the exception of hardware. Even then it is more casual usage. Although I think it's mainly because when you are putting parts or sheet metal on an aircraft, that the material be "aircraft grade" is taken for granted and expected. (Especially for the A&P whose ticket and tuckus is on the line if there is a problem...) There is a difference in the materials themselves (hate to admit it, because I HATE being out of pocket for some of the parts $$$$) Take engine parts for example: Can you take your car out of the driveway, warm it up half-ass, and blast down the street at wide open throttle for a couple minutes, then back of to 70% throttle for a few hours, then idle for a bit, shut it off, and FULLY expect to do the same every time you drive it?

...A basic extruded billet that has been fluxed to determine grain direction would never stand up in the compressor of a jet engine. they're not even used on the cold side....

 

[aviator41]

Yes. thats what I'm saying. I added the "one the cold side" comment in case a reader didn't know what it was I was talking about.

 

[zodiacflyer]

Ok...check....disregard.... You fly a Mooney? What part of the AV Biz are you in?

 

[aviator41]

Yes, I fly an older C series, but I like the new mooney logo better that the old one. The only money pit bigger than a boat is an airplane. BUT: there are a lot of things I'd give up before flying.

As far as the aviation industry, I'm on the electronic side of turbofans. Low level programmig for digital FMS.

Are you a Light Sport pilot? I'm assuming the Zodiac in your name is the airplane. (very cool line of aircraft. I'm fond of the Zenith CH650.)

 

[zodiacflyer]

I flew an M20 a few years ago. Money pit is right; nothing like watching money disappear into thin air... I am a private pilot, and am in school at TCC in tulsa to get my Commercial, multi, and Instrument. I am also an A&P, but drive a dump truck right now. The schedule is more flexible, and the boss doesn't mind my knocking off early three days a week for school, and I still get 50-65 hours per week.

I am building a Zodiac now, and it will have a chevy engine (corvair)