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#1
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4130 frame?
Has anyone on this list ever welded a thinwall 4130 frame with a MIG welder?
What is a good source of 4130 seamless and welded seam tubing? Thanks, -- Have a good one! Steve www.americanspiritppc.com |
#2
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On Sat, 23 Aug 2003 01:44:47 GMT, "Steve Thomas"
wrote: :Has anyone on this list ever welded a thinwall 4130 frame with a MIG welder? Most aircraft welding is done TIG : :What is a good source of 4130 seamless and welded seam tubing? Dillsberg Aero. They don't have a website, but you'll get their address if you google them. |
#3
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Steve Thomas wrote:
Has anyone on this list ever welded a thinwall 4130 frame with a MIG welder? What is a good source of 4130 seamless and welded seam tubing? Thanks, I use a Lincoln Weldpak 100 to tack everything together, but the MIG has a tendency to either not penetrate or blow holes. Very hard to balance on the line. I just tried TIG, after putting nearly the whole frame together with oxy/acetylene. I'll stick with the oxy/acetylene, because the TIG gave me the same results that I got with MIG. Either not penetrating or blowing holes. -- ----Because I can---- http://www.ernest.isa-geek.org/ ------------------------ |
#4
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MIG is not normally recomended for airframe construction but many people do
it. I have TIG and O&A welded and prefer TIG but hard to get into clusters with the TIG torch. See news:sci.engr.joining.welding for lots of good (factual) helpfull information. Jim "Steve Thomas" wrote in message nk.net... Has anyone on this list ever welded a thinwall 4130 frame with a MIG welder? What is a good source of 4130 seamless and welded seam tubing? Thanks, -- Have a good one! Steve www.americanspiritppc.com |
#5
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Dillsburg in Pa. is the best source that I know of for steel and al..You
can use mig with a lot of practice but you might like o/act.a lot better.Go to tinman . com for further advise. |
#6
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A few years back, a manufacturer of 4130 tube frames for a popular high-wing
kit used TIG because of production and training considerations over oxy/acetylene. They had to call back fuselages because of cracking in the 4130. They modified their approach and used oxy/acetylene to pre-heat and post-heat the weld. They ended up with nice welds, but why not just train enough welders to the a real good job with oxy/acetylene? 4130 is very touchy about cracking from too little pre-heat and from too fast cooling of the weld AND the metal around the joint. It should be welded in absolutely calm air and the torch flame must be adjusted correctly to avoid a brittle failure from random hydrogen in the air. Some of the race car guys who were using 4130 found that they could get very strong joints (with less high-heat problems)by using a brazing technique rather than true welding. In fact, the technique seemed to provide better joints due to difficult clusters and different levels of expertise. There are some very good brazing alloys out there now with very high PSI ratings. As with a good 4130 "weld" the joints must be a very good fit (NO gap filling with the rod) and clean, clean, clean. You can shape various grinding wheels, or you can use something like the "joint jigger" with high quality hole saws to form the various "fish mouth" shapes. The best jigs permit adjustment of the vise angle and the drill angle. The best quality of the hole saws will do an entire frame before sharpening or replacement is required. Finding a full selection of tubing wall/id/od combinations is difficult today. We ran into a source problem a couple of years ago when we needed to find some sections that would telescope over an existing tube during some airframe repair. This was a case where replacing the entire length of the structural member would have required a re-cover of the fuselage. If you are working on a definate project and have too much trouble finding the size you need from one of the three aircraft suppliers that still stock a decent selection of 4130 tube, send me an email and I will pass along a couple of sources that don't generally advertise. J "Steve Thomas" wrote in message nk.net... Has anyone on this list ever welded a thinwall 4130 frame with a MIG welder? What is a good source of 4130 seamless and welded seam tubing? Thanks, -- Have a good one! Steve www.americanspiritppc.com |
#7
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Where can you get these "high quality" hole saws? Even with cutting fluid
and cool air from a compressor I'm luckey to get 20 or so cuts from your standard Milwakee hole saw. "You can shape various grinding wheels, or you can use something like the "joint jigger" with high quality hole saws to form the various "fish mouth" shapes. The best jigs permit adjustment of the vise angle and the drill angle. The best quality of the hole saws will do an entire frame before sharpening or replacement is required. |
#8
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Find a copy of Winmiter.zip.
THis little program allows you to print out cutting templates on your computer. Then just grind to shape. I use a modified 4" angle grinder to cut the tubes. It's spooky how accurate this works. Richard Sandy wrote: Where can you get these "high quality" hole saws? Even with cutting fluid and cool air from a compressor I'm luckey to get 20 or so cuts from your standard Milwakee hole saw. "You can shape various grinding wheels, or you can use something like the "joint jigger" with high quality hole saws to form the various "fish mouth" shapes. The best jigs permit adjustment of the vise angle and the drill angle. The best quality of the hole saws will do an entire frame before sharpening or replacement is required. |
#9
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Richard Lamb wrote: Find a copy of Winmiter.zip. THis little program allows you to print out cutting templates on your computer. Then just grind to shape. I use a modified 4" angle grinder to cut the tubes. It's spooky how accurate this works. Richard ++++++++++++++++++++++++++++ Sheesh! Whatz really spooky is -- how you leave a poor soul dangling with... FIND A COPY OF WINMITER.ZIP Barnyard BOb to the rescue.... [I think] ftp://ftp.ihpva.org/pub/software/winmiter/ ftp://ftp.ihpva.org/pub/software/index.html |
#10
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J,
Thanks for that helpful insight. I will keep it all in mind. Sice I do not have a TIG machine or experience using one, and I do not have much experience using a torch to weld with, would it be kosher to tack the pieces together with a MIG and then have a professional welder finish the process by using a torch? The local pro that I have used in the past for various projects gave me the impression that he would rather weld with his a/o torch than his TIG machine. -- Have a good one! Steve www.americanspiritppc.com "Flightdeck" wrote in message ink.net... A few years back, a manufacturer of 4130 tube frames for a popular high-wing kit used TIG because of production and training considerations over oxy/acetylene. They had to call back fuselages because of cracking in the 4130. They modified their approach and used oxy/acetylene to pre-heat and post-heat the weld. They ended up with nice welds, but why not just train enough welders to the a real good job with oxy/acetylene? 4130 is very touchy about cracking from too little pre-heat and from too fast cooling of the weld AND the metal around the joint. It should be welded in absolutely calm air and the torch flame must be adjusted correctly to avoid a brittle failure from random hydrogen in the air. Some of the race car guys who were using 4130 found that they could get very strong joints (with less high-heat problems)by using a brazing technique rather than true welding. In fact, the technique seemed to provide better joints due to difficult clusters and different levels of expertise. There are some very good brazing alloys out there now with very high PSI ratings. As with a good 4130 "weld" the joints must be a very good fit (NO gap filling with the rod) and clean, clean, clean. You can shape various grinding wheels, or you can use something like the "joint jigger" with high quality hole saws to form the various "fish mouth" shapes. The best jigs permit adjustment of the vise angle and the drill angle. The best quality of the hole saws will do an entire frame before sharpening or replacement is required. Finding a full selection of tubing wall/id/od combinations is difficult today. We ran into a source problem a couple of years ago when we needed to find some sections that would telescope over an existing tube during some airframe repair. This was a case where replacing the entire length of the structural member would have required a re-cover of the fuselage. If you are working on a definate project and have too much trouble finding the size you need from one of the three aircraft suppliers that still stock a decent selection of 4130 tube, send me an email and I will pass along a couple of sources that don't generally advertise. J "Steve Thomas" wrote in message nk.net... Has anyone on this list ever welded a thinwall 4130 frame with a MIG welder? What is a good source of 4130 seamless and welded seam tubing? Thanks, -- Have a good one! Steve www.americanspiritppc.com |
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