Danb Posted June 23, 2020 Report Share Posted June 23, 2020 3 minutes ago, M20Doc said: And America has been waging war (Militarily and economically) everywhere on just about everyone including their allies ever since. Clarence Yeah we’re hired to,protect half the world, most of them forget to pay for our defense. Dumb ass politicians 1 1 Quote Link to comment Share on other sites More sharing options...
Blue on Top Posted June 23, 2020 Report Share Posted June 23, 2020 Just now, Danb said: Yeah we’re hired to protect half the world, most of them forget to pay for our defense. @M20Doc And, while your boys were still partying on Dec 24, 1944, my father took a swim in the Channel for them. Google "Leopoldville", one of the largest naval losses of WWII (853 people lost their lives). Quote Link to comment Share on other sites More sharing options...
aviatoreb Posted June 23, 2020 Report Share Posted June 23, 2020 (edited) 9 minutes ago, Blue on Top said: 1. Costs would be significantly higher (not plus $1M but go from 850K to $1M) because of the number of frames made (especially versus bicycles) all new machining tooling and "automated" welding? TT bikes are stiff to get every fiber of human horsepower to the road. Stiffness transfers power well. A good comparison would be to compare component to component price between the materials. My aluminum frame bike is 30% cost of the same frame in carbon. How does a titanium rear cassette set compare to a standard steel set? Yes, it might only be $200 more, but it's also 3 times more expensive ($100 steel versus $300 titanium). 1000s of each bike type are produced annually, too. 3. You have a very intelligent friend; keep him/her. Grumman airplanes were bonded together. We can bond today, but we'd also have to design in a few chicken fasteners here and there in case the bond sheared apart. Yes, composite airplanes have to do that, too. I don't know much about actual cost. But I have purchased bike parts produced to spec from a cad drawing as a one off. And it was less expensive by a factor of ten sourcing it from this chinese company. I custom built-design both my tt bike and my mtn bike this way. My road bike was built in the usa. The price difference was about a factor of 10. http://www.xacd.com.cn/product.asp?rootcl=1 Check out the cassette at the bottom of this page and you get an idea of how intricate that can be. http://www.xacd.com.cn/product.asp?rpag=3&rootcl=3&cls=0# The crank arms you see on this page are the actual crank arms on my bike. http://www.xacd.com.cn/product.asp?rpag=2&rootcl=3&cls=0 I.e., they photographed them before they sent them to me. http://www.xacd.com.cn/product.asp?rpag=4&rootcl=3&cls=0# As far as cost for an airplane - I don't know. But my guess has been that it is certification and insurance that carries most of the cost. The marginal cost of actually building a bit of material - like a AL tube or a chromoly tube (which is actually used) and a Ti tube isn't that huge. My impression. I know certain USA brands that use this very company, then they turn around and sell the same bike at a ten times markup. In fact, I was all set about 10 years ago to buy a '"built in the usa" bike from a certain well known brand in Tennessee when researching I learned that in fact a lot of its products are built by this factory in X'ian. So back then I decided to be my own source agent and I both had an absolutely custom bike spec'ed and built from my cad all angles and such as I wanted, and surprisingly less expensive. I am all for supporting the american workmanship and american worker, and I bend over backwards to do so, especially when it is local - my town - but even generally - but I am not at all into spending any extra to support the american middle man outsourcing agent and I am happy to do that myself when I can. OK - anyway if not a complete airplane, I always thought that lots of the bits could be made in Ti built just like building a bike. Landing gear, jack screw, lots of heavy metal parts. That are none of these much more intricate than tubes all welded together like on my bike. If it were not for the stc legal process - then I would do exactly that. So I will emphasize again - they are building for me one part at a time. One off - I send a cad and 3 months later I receive a perfect part. Sometimes its welded tubes and sometimes its CNC - depending on what is needed. But definitely not mass production as it is from my specific cad. Edited June 23, 2020 by aviatoreb 1 Quote Link to comment Share on other sites More sharing options...
Blue on Top Posted June 23, 2020 Report Share Posted June 23, 2020 5 minutes ago, aviatoreb said: Landing gear, jack screw, lots of heavy metal parts. That are none of these much more intricate than tubes all welded together like on my bike. If it were not for the stc legal process - the@aviatorn I would do exactly that. @aviatoreb I like the way you're thinking, and you're correct! I know the certification processes well (and am on a couple of ASTM committees writing the new compliance to Part 23). What I am not sure about with Ti is heat transfer, temperature vs strength properties (which I believe are very good) and fatigue (which I think is not so good). 2 Quote Link to comment Share on other sites More sharing options...
aviatoreb Posted June 23, 2020 Report Share Posted June 23, 2020 (edited) 16 minutes ago, Blue on Top said: @aviatoreb I like the way you're thinking, and you're correct! I know the certification processes well (and am on a couple of ASTM committees writing the new compliance to Part 23). What I am not sure about with Ti is heat transfer, temperature vs strength properties (which I believe are very good) and fatigue (which I think is not so good). Hi - I don't know heat transfer priorities either. But am I remembering correctly that there were lots of parts in the SR71 were Ti was chosen specifically because of its heat transfer properties? Fatigue life is considered "infinite" at least in a bicycle application. Steel - chromoly bikes wear out and get tired noticeably during the life of a bike rider over just a few years but on human scales at least a Ti bike will last longer than the human. My main every day rider, my road bike, is over 15 years old and indistinguishable from new. That said, this is hardly a way to do the engineering needs. but I know it is known just not by me. In fact fatigue life, non-corrosiveness (and cycling is a horribly corrosive environment between sweat that is highly corrosive and of course road salt, etc), and also vibration dissipation that is very very nice for Ti, and weight ad strength (strong like steel but light like Al), it is the perfect metal for this application. I remember watching a documentary about the two companies that had contracts to compete in building the F35 design and one of them made a very complex center bulk head out of Ti for several of the properties you just called out. It was outrageously expensive big and intricate. I forget if that was the company that eventually got the design thumbs up and builds our F35 today. But certainly nothing in a Mooney is that big. crash-strength - I don't know. I bet just in changing out a few large parts, gear, jack screw, steering column, etc, a hundred pounds (more? -just making up numbers...) could be saved in a Mooney at not too much material cost. I had my Ti tt bike custom built for $600 about 10 years ago (1/10th of equivalent in Tennessee) its comparable in complexity to a landing gear on my mooney in my opinion. So sounds like you know better than I do by a long shot - the STC process would be so expensive it would overwhelm thee cost possibility of doing it. Edited June 23, 2020 by aviatoreb 1 Quote Link to comment Share on other sites More sharing options...
carusoam Posted June 23, 2020 Report Share Posted June 23, 2020 Many ‘original’ ideas of machining Ti failed... Many of their failures were related to using the techniques of machining other metals...plenty of non-computerized machining was tried... Other failures were related to the manhours that machining the slower to cut material required... The cutting tools are different as well... Another failure we discussed related to bike parts... the brittleness, cracks and crack propagation... requires attention to detail... leave no stress multipliers behind after manufacturing... finish processing that was not done for other parts... So... machining of Ti isn’t terrible... but it does require some modern machinery to go with that to be economical... Consider for a moment an ‘easy’ swap of certain tubes... that are bolt-on in nature... Easy... as in tubes change dimension based on their strength...so they are not a one for one kind of swap... The density of Ti is near 1/2 of chromoly steal.... What do Mooney landing gear weigh? would these Make an interesting swap? How about the engine mount? It is bolt on as well... is there something to be gained here? Or is the vibration and heated environment not acceptable to Ti? a really fun engineering experiment would be to duplicate the airframe that doc is working on... His Mite’s frame looks a lot like a Ducati in size... slightly larger than a bicycle... Getting Doc’s tube frame duplicated in Ti would get back some UL where it really counts... PP thinking out loud... Best regards, -a- 2 Quote Link to comment Share on other sites More sharing options...
ArtVandelay Posted June 23, 2020 Report Share Posted June 23, 2020 We’re talking about Ti as if only has 1 kind, like iron there are alloys with different characteristics. Also a quick web search shows CF is half the density of Al, and CF is stronger.I think the gear or engine is probably the best candidate for weight reduction due to exotic materials. Quote Link to comment Share on other sites More sharing options...
carusoam Posted June 23, 2020 Report Share Posted June 23, 2020 12 minutes ago, ArtVandelay said: We’re talking about Ti as if only has 1 kind, Because writing the technical detail to have a casual conversation takes extra key-strokes... And sometimes... the proper alloy for each application is actually unknown to many MSers... But I digress... Which alloys of Ti are Best or replacing tubes in a Mooney... would they all be the same...? Or would the legs be different than the engine mount? PP thoughts only, not a materials engineer... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted June 24, 2020 Report Share Posted June 24, 2020 I used to work with a guy who spent 5 years welding Ti bike frames. He said welding Ti is a lot more difficult then CrMo steel. He said they need to fill the inside of the tubes with cover gas and purge the area around the weld with cover gas. After all that it welds beautifully. 2 Quote Link to comment Share on other sites More sharing options...
Blue on Top Posted June 24, 2020 Report Share Posted June 24, 2020 1 hour ago, ArtVandelay said: Also a quick web search shows CF is half the density of Al, and CF is stronger. I think the gear or engine is probably the best candidate for weight reduction due to exotic materials. @ArtVandelay As Abraham Lincoln once said, "Don't believe everything you read on the internet." Seriously, though, there may be some parts on an airplane that can be lighter in CF, but more likely they are easier to make in CF than aluminum (like the cowling) than to be lighter than aluminum. The vast majority of material failure modes on an airplane are in compression/buckling where CF is poor at best (it's all the resin/matrix/glue). Aluminum has known buckling loads and fatigue characteristics; CF does not. Please don't Google "CF fatigue". Composites have a fatigue life just like everything else. What they don't have is warning signs of fatigue failure. After it fails, the matrix dust blows away. CF is also poor with point loads, and a metallic (typically titanium, LOL) insert needs to be installed to transfer the loads through a larger surface area. I agree with you on potential areas to remove weight (the wing spar, too), but would the weight savings be worth the cost of certification? Quote Link to comment Share on other sites More sharing options...
aviatoreb Posted June 24, 2020 Report Share Posted June 24, 2020 I've heard that about welding Ti tubes as well - requires specialized welding procedures. 3AL2.5V is the alloy of Ti for tubes and welding since it is supposed to be more malleable. Ti-6Al-4V is use in harder machined applications like making Ti hardware. I crave Ti like some people like gold. I just got a Ti crank bolt set that I installed on my bike over the weekend. Saves a few grams. Its hard and stays clean not corroded looking forever. I have a Ti watch. (The watch case and the band). https://www.ebay.com/i/302265986903?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=302265986903&targetid=921377350772&device=c&mktype=pla&googleloc=9005349&poi=&campaignid=9344508364&mkgroupid=96003368313&rlsatarget=pla-921377350772&abcId=1139336&merchantid=118847604&gclid=EAIaIQobChMIyse6hKCZ6gIVhcDICh0bTwbzEAQYAyABEgIo0vD_BwE 1 Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted June 24, 2020 Report Share Posted June 24, 2020 Just now, aviatoreb said: I've heard that about welding Ti tubes as well - requires specialized welding procedures. 3AL2.5V is the alloy of Ti for tubes and welding since it is supposed to be more malleable. Ti-6Al-4V is use in harder machined applications like making Ti hardware. I crave Ti like some people like gold. I just got a Ti crank bolt set that I installed on my bike over the weekend. Saves a few grams. Its hard and stays clean not corroded looking forever. I have a Ti watch. (The watch case and the band). https://www.ebay.com/i/302265986903?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=302265986903&targetid=921377350772&device=c&mktype=pla&googleloc=9005349&poi=&campaignid=9344508364&mkgroupid=96003368313&rlsatarget=pla-921377350772&abcId=1139336&merchantid=118847604&gclid=EAIaIQobChMIyse6hKCZ6gIVhcDICh0bTwbzEAQYAyABEgIo0vD_BwE Well, I do ride a Ti bike and have a Ti watch! 1 Quote Link to comment Share on other sites More sharing options...
aviatoreb Posted June 24, 2020 Report Share Posted June 24, 2020 12 minutes ago, Blue on Top said: I agree with you on potential areas to remove weight (the wing spar, too), but would the weight savings be worth the cost of certification? Right - the wing spars. Seems entirely do-able in engineering terms. And from my non-expert but entirely experiential experience, the extra cost in the many parts that would be sensible to work in Ti instead of Al or chromoly willl increase the cost but the majority of the cost is certification. Many of the parts would be exact replicas in ti, wing spars, jack screw, etc, so they would be stronger. Some parts would be changed based on the relative strength, eg design the tubing when its tubing parts, appropriate for the relative strengths rather than just replicate as you might do for some machined parts. Your question is would it be worth the cost of certification - I would say - yes. What it is 200, or 300, or 400 lbs could be saved by trading out other metals for Ti? Well that would be an absolute game changer and would turn the Mooney into a two person machine to a four person machine. Would it be worth it? Well if they can get the factory up and running. Could they afford not to do such a thing? It would be cheaper I bet than certifying an entirely new airplane from scratch. ...and I would recommend smooth glued on no rivet skins of some kind, wether AL or carbon or whatever. It would be smoother and so a tad faster but also most important, a bit faster to build I would guess since less parts. Quote Link to comment Share on other sites More sharing options...
aviatoreb Posted June 24, 2020 Report Share Posted June 24, 2020 3 minutes ago, N201MKTurbo said: Well, I do ride a Ti bike and have a Ti watch! I think you are my kind of guy! !!! I think You too need Ti chain ring bolts. 1 Quote Link to comment Share on other sites More sharing options...
Hank Posted June 24, 2020 Report Share Posted June 24, 2020 14 minutes ago, aviatoreb said: I have a Ti watch. (The watch case and the band). https://www.ebay.com/i/302265986903?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=302265986903&targetid=921377350772&device=c&mktype=pla&googleloc=9005349&poi=&campaignid=9344508364&mkgroupid=96003368313&rlsatarget=pla-921377350772&abcId=1139336&merchantid=118847604&gclid=EAIaIQobChMIyse6hKCZ6gIVhcDICh0bTwbzEAQYAyABEgIo0vD_BwE I was expecting a titanium watch . . . . . 1 Quote Link to comment Share on other sites More sharing options...
carusoam Posted June 24, 2020 Report Share Posted June 24, 2020 If you were expecting one thing and got something different... you got bolted? These things have a lot of precision compared to an ordinary bolt... in aviation even more precision is required... as Turbine Tom pointed out with the variation of the shank’s diameter compared to the inner diameter of the holes... a small imprecision the bolt doesn’t fit, or it has too much wobble... (how is that for retrieval of a Unique stored memory?) Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Blue on Top Posted June 24, 2020 Report Share Posted June 24, 2020 Although I'm drooling over your Ti bicycles and watches, I still love my aluminum Specialized Secteur Elite. I'm just an old guy that's done a couple Half Ironmans. 2 Quote Link to comment Share on other sites More sharing options...
aviatoreb Posted June 24, 2020 Report Share Posted June 24, 2020 17 minutes ago, Blue on Top said: Although I'm drooling over your Ti bicycles and watches, I still love my aluminum Specialized Secteur Elite. I'm just an old guy that's done a couple Half Ironmans. Running?! Why would you run when you have a perfectly good bike? Swimming?! You would just get wet. No joke but Im not fan of Al. Being a "Clydesdale" bike rider, I have...had 2 different frames crack and break on me, one catastrophically during a race. ouch. And I have broken 4 different cranksets - all four catastrophically snapped in two in sprint - luckily only one was a crash and just a little minor broken bone... I have all my bike parts custom built Clyde-style. 1 Quote Link to comment Share on other sites More sharing options...
aviatoreb Posted June 24, 2020 Report Share Posted June 24, 2020 Back to airplanes ... what if there really is 200? 400? lbs of low hanging fruit of some metal parts that if they could be traded for some Ti parts - not necessarily everything but just some parts - what if all of a sudden the Mooney had 400lbs of extra payload? 1 Quote Link to comment Share on other sites More sharing options...
carusoam Posted June 24, 2020 Report Share Posted June 24, 2020 Four seats, bags for a week, and full fuel... and the ability to fly 900nms... We need to weigh the gear parts... and jack screw... It may be difficult to find hundreds of pounds of steel being used... But whatever we find, cut in in half to work the numbers... -a- 1 Quote Link to comment Share on other sites More sharing options...
aviatoreb Posted June 24, 2020 Report Share Posted June 24, 2020 4 minutes ago, carusoam said: Four seats, bags for a week, and full fuel... and the ability to fly 900nms... We need to weigh the gear parts... and jack screw... It may be difficult to find hundreds of pounds of steel being used... But whatever we find, cut in in half to work the numbers... -a- So as I see it this would be a two stages of plausible. As a thought experiment. 1)...my guess - landing gear, and jack screw and a few other parts - and some bolts etc....good weight. and not crazy absurd to certify Ti replacement parts. And not crazy expensive to build. 2) Then it gets more serious and more structural...wind spars, engine cage, even Frame cage, all plausible in my mind to trade for Ti. More weight but then more serious cost to certify. Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted June 24, 2020 Report Share Posted June 24, 2020 5 minutes ago, carusoam said: Four seats, bags for a week, and full fuel... and the ability to fly 900nms... We need to weigh the gear parts... and jack screw... It may be difficult to find hundreds of pounds of steel being used... But whatever we find, cut in in half to work the numbers... -a- Remember @M20Doc‘s mite fuselage. He said it weighed 17 pounds. Let’s say the M20 steel cage weighs 4 times as much and w3 can reduce it by 20% with Ti. That is only a 14 lb saving. Hardly seems worth it. 3 Quote Link to comment Share on other sites More sharing options...
carusoam Posted June 24, 2020 Report Share Posted June 24, 2020 See if @Alan Fox can weigh some steel parts for us... ? (Landing gear and trim jack screw) This May help Alan sell some parts too... Best regards, -a- 1 Quote Link to comment Share on other sites More sharing options...
aviatoreb Posted June 24, 2020 Report Share Posted June 24, 2020 2 minutes ago, N201MKTurbo said: Remember @M20Doc‘s mite fuselage. He said it weighed 17 pounds. Let’s say the M20 steel cage weighs 4 times as much and w3 can reduce it by 20% with Ti. That is only a 14 lb saving. Hardly seems worth it. Could be only 14lbs. If that's all then definitely not worth it. How much does a bare bones Mooney weight, all in, no avionics, no rubber, no engine, no interior - just the frame and skins metal bits? Quote Link to comment Share on other sites More sharing options...
carusoam Posted June 24, 2020 Report Share Posted June 24, 2020 Hmmmm.... Titanium seat frames... They simply can’t get more expensive... Empty weight Of an M20K is 1800LBs.... about 300 for power plant... 100 for the interior... leaving 1-1.5 k#s of metal... Pure PP guesses only... Best regards, -a- 1 Quote Link to comment Share on other sites More sharing options...
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