---------------------------------------------------------- Zenith601-List Digest Archive --- Total Messages Posted Mon 04/18/11: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:41 AM - Chat Room (George Race) 2. 04:21 PM - A couple of questions () 3. 04:24 PM - Alternators for Corvairs () 4. 04:31 PM - Re: A couple of questions (Craig Payne) 5. 05:25 PM - Re: A couple of questions (Randy L. Thwing) 6. 05:33 PM - Re: A couple of questions (Jay Bannister) 7. 06:21 PM - Re: A couple of questions () ________________________________ Message 1 _____________________________________ Time: 05:41:01 AM PST US From: "George Race" Subject: Zenith601-List: Chat Room Live Chat Room every Monday evening around 8:00 EDT http://www.mykitairplane.com Click on the Chat Room link at the top of the page. George ________________________________ Message 2 _____________________________________ Time: 04:21:37 PM PST US From: Subject: Zenith601-List: A couple of questions First question: Given the same number of longerons and bulkheads, would a triangular fuselage be as strong, or stronger than a square or round one? Aeronautical engineers, and those who already found out empirically, and anybody with an opinion, feel free to jump in. Second question....Several years ago, someone figured out the weights of 4 by 12 (I think) sheets of .016, .025, and .032 aluminum. Does anybody remember them? Paul R ________________________________ Message 3 _____________________________________ Time: 04:24:15 PM PST US From: Subject: Zenith601-List: Alternators for Corvairs Has anybody used a different alternator than the John Deere? The current price (no pun intended) of $335 seems a bit high for 20 amps, and I'd like to explore other possibilities before diving in.......What other options have been tried? Thanks, Paul R ________________________________ Message 4 _____________________________________ Time: 04:31:59 PM PST US From: "Craig Payne" Subject: RE: Zenith601-List: A couple of questions For your second question, Spruce has a good reference table: http://www.aircraftspruce.com/catalog/graphics/generalaluminuminfo2small.jpg -- Craig From: owner-zenith601-list-server@matronics.com [mailto:owner-zenith601-list-server@matronics.com] On Behalf Of paulrod36@msn.com Sent: Monday, April 18, 2011 4:17 PM Subject: Zenith601-List: A couple of questions First question: Given the same number of longerons and bulkheads, would a triangular fuselage be as strong, or stronger than a square or round one? Aeronautical engineers, and those who already found out empirically, and anybody with an opinion, feel free to jump in. Second question....Several years ago, someone figured out the weights of 4 by 12 (I think) sheets of .016, .025, and .032 aluminum. Does anybody remember them? Paul R ________________________________ Message 5 _____________________________________ Time: 05:25:58 PM PST US From: "Randy L. Thwing" Subject: Re: Zenith601-List: A couple of questions Paul: You never need a chart if you remember (or write down) that in most books Aluminum is listed (generally) as weighing .10/ lbs per cubic inch. Now I recall 6061-T6 is a bit lighter at .098/lbs per cubic inch. So you just have to multiply any sheet size: length times width times thickness equals cubic inches of material which is then multiplied by .098 to give you the sheet weight. Example: 4' x 12' x .016" sheet. 48" x 144" x .016" = 110.592 cubic inches of material x .098 (weight per cubic inch) = 10.838 lbs. per sheet. Other (general) handy weights to know are: Steel or stainless steel = .283/lbs per cubic inch Brass = .307/lbs per cubic inch lead = .409/lbs per cubic inch How to remember these numbers? Note all are Chevy engine cubic inch sizes! You just have to remember the AL figure. Regards, Randy, Las Vegas Second question....Several years ago, someone figured out the weights of 4 by 12 (I think) sheets of .016, .025, and .032 aluminum. Does anybody remember them? Paul R ________________________________ Message 6 _____________________________________ Time: 05:33:23 PM PST US Subject: Re: Zenith601-List: A couple of questions From: Jay Bannister Paul, The answer to your question is not a simple one. In the first place, they would not all have the same number of longerons. A triangular one could on ly have three. A square one would have four and a round one would have fou r or more. The size and configuration of the bulkheads would also be very different, even if the number of them were equal. You would also have to t ake into account diagonal bracing and skin thickness. If you are asking ab out the frame alone, each shape could be designed to have the same strength as the others. A fuselage made of only two longerons can be made to work and to be as strong as any of the other shapes. And the term "strength" in this case is a rather nebulous one. In the design of an airplane fuselage , the practicality of the shape is more important than the theoretical stre ngth of the shape. How do you fit people into the shape? How do you att ach the wings and empennage? How do you secure the engine? What are the ae rodynamic characteristics of the fuselage? And so on and so forth. I know this is not what you wanted to hear, but your question can't be answ ered simply. If you really want a triangular shaped fuselage, you have thou ght it through and can arrange to have a thorough structural analysis done, I'd say go for it. Jay ________________________________ Message 7 _____________________________________ Time: 06:21:02 PM PST US From: Subject: Re: Zenith601-List: A couple of questions Many thanks to Craig, Randy and Jay for the quick turnaround on my questions. Since I'm built pretty much like anybody else, the cockpit would "violate" the pyramidal esthetics, but it was more of a mental exercise in design than something to make another project out of. Maybe someday, just for fun, though. Paul R ----- Original Message ----- From: Jay Bannister To: zenith601-list@matronics.com Sent: Monday, April 18, 2011 7:27 PM Subject: Re: Zenith601-List: A couple of questions Paul, The answer to your question is not a simple one. In the first place, they would not all have the same number of longerons. A triangular one could only have three. A square one would have four and a round one would have four or more. The size and configuration of the bulkheads would also be very different, even if the number of them were equal. You would also have to take into account diagonal bracing and skin thickness. If you are asking about the frame alone, each shape could be designed to have the same strength as the others. A fuselage made of only two longerons can be made to work and to be as strong as any of the other shapes. And the term "strength" in this case is a rather nebulous one. In the design of an airplane fuselage, the practicality of the shape is more important than the theoretical strength of the shape. How do you fit people into the shape? How do you attach the wings and empennage? How do you secure the engine? What are the aerodynamic characteristics of the fuselage? And so on and so forth. I know this is not what you wanted to hear, but your question can't be answered simply. If you really want a triangular shaped fuselage, you have thought it through and can arrange to have a thorough structural analysis done, I'd say go for it. Jay http://www.matronics.com/Navigator?Zenith601-List http://www.matronics.com/contribution ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message zenith601-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Zenith601-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/zenith601-list Browse Digests http://www.matronics.com/digest/zenith601-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.