Keb said:
Zonie said:
If you don't wish to believe me, that's fine.
This is not the place to present my credentials or industrial background.
I would think it is the perfect place to present your credentials & background. How do you expect to convince me you know what you're talking about without that?
OK. Those not interested may not want to read thru all of this and I can't say I would blame you. :grin:
My College education was in Mechanical Design and Secondary Education, Industrial Arts.
I only officially used my Education degree to teach some College level classes on Geometric Tolerancing and Design.
While I was still in College I hired into a company that produces jet engines, Auxiliary Power Units which are gas turbine engines that supply starting, ground power and emergency in flight power on commercial and military aircraft and ground applications, and control systems.
I started my 40 year career in Tool Design designing special cutting tools, jigs, holding fixtures, weld fixtures, form/piercing dies and special gages, Electrochemical (ECM) and Electrical Discharge (EDM) tooling.
I also designed special machines required to produce hardware for which commonly available machines were not made.
I also designed many special gaging machines which measure multiple features for turbine and compressor blades (bow, twist, lean, displacement and other critical dimensions).
I then worked as a Quality Assurance (Quality Control) Engineer for several years specializing in Engineering Design review for specifications, inspect-ability and Geometric Tolerancing.
I moved into Engineering Design in the APU branch of the company designing hardware and systems for Military applications, both ground and airborne.
I've worked on the APU designs for the B1, F15, F18 and F22 and others.
I was promoted to Lead Designer for the (then new) Airbus A330 and 340 Auxiliary Power Unit.
Following this I was the Lead Designer for the Boeing 777 APU.
With these programs I was responsible for system compatibility and interfaces as well as for the design of all things which goes into or onto the Auxiliary Power Units.
Following this I became the Principal Designer for all of the Large Commercial APU's made by our company. These are used on the Boeing 720, 757, 767, 777 and the Airbus A320, A330 and A340.
In this position no part of any of the APU's I was responsible for could be changed without my approval. All proposed designs required my approval before they could be finalized.
All problems with these engines, whether it was a functionality or repair-ability issue was directed to me for resolution.
I also served as a consultant on all new and proposed APUs (both large and small) for applications coming down the pike.
While in Engineering Design I was expected to have a through knowledge of manufacturing, inspection, stress analysis, material properties, rotor dynamics and basic thermodynamics.
We had many Engineers who were specialists at all of these for running complex stress analysis, materials analysis, bearing analysis, controls analysis, dynamic analysis etc, and these people would analyze my proposed designs.
I often did the simpler calculations required for these designs so that they would not require major revisions following these more complex and detailed studies by the experts.
(May I say I have worked with some of the best of these people in the world.)
Although I have extensively used Computer-Vision and Catia computer design in 2D and 3D and although these systems both are useful for doing stress and vibration analysis, the simpler stress and thermodynamic calculations were often easier to do by hand hence, my knowledge of these areas is not limited.
I hope I didn't come off sounding like the Great Someone here but you asked for my background.
As for DOM tubing, I am not totally against using it for a gun barrel.
There are some alloys available which have material properties high enough that they can overcome the manufacturing weaknesses of the process. These alloys are not low carbon steel (1018, 1020 etc.).
I must point out that even these high strength alloys in their annealed condition are no better than 1018 unless they are properly heat treated to bring out their inherent strengths.
Have a good one!