7005 Aluminum

Date 02-28-2004 03:59

My son wants to build a recumbent tricycle. I have seen some plans and they look pretty good. I recomemded to him to find some bike frames for sale made from aluminum. That way we could cut and fit instead of build everything from scratch. He found two frames on EBay that would do for the project, but one was made from 7005 aluminum. In the photos they looked welded. Is 7005 weldable? Or did they solder them? If weldable, anything we should know about technique or filler?

By Chris04 Date 03-05-2004 17:44

I don't have any first-hand experience with 7005, but you should be able to weld it with 5356 filler and obtain acceptable strength in the as-welded condition. I wouldn't suggest using 4043. There's plenty of folks on this board who are more knowledgable than me in this area, so I hope they'll speak up if I'm giving poor advice here. Good luck,

Chris

By Lawrence (*****)

Date 03-06-2004 17:20

Happy bear,

Yes you can weld it. The first link is some filler matching data. The second link is important heat treating information that must be considered when joining precipitation hardenable aluminum alloys such as 7005 and 6061. Those bikes have some pretty severe cyclic and torsional loads/stresses which will cause problems for tubes left in the as welded condition.

http://www.jwharris.com/welprod/alalloys/

http://www.mtbreview.com/files/data/250.html

By happybearwelder (*)

Date 03-06-2004 22:36

I looked at the links, they are very informative. So informative that we must rethink the whole project. Thanks

By LarryL

Date 03-09-2004 03:10

If I were to build a recumbent bicycle, I'd consider building this design which can be fabricated from the steel frames of existing bicycles:

http://www.atomiczombie.com/!marauder.htm

The designer seems to be a whiz at creating bicycles and robots. He may be crazier than most of us, however, as he has already ridden his 12 foot tall bicycle - 12 foot seat height made it a Guiness world record - and has plans to ride a 24 foot tall one after he's completed it.

By LarryL

Date 03-09-2004 03:12

Look for the "Marauder recumbent bicycle" on his website.

By welder_guy2001 (***)

Date 03-07-2004 01:42

I had no idea aluminum was so picky! I'll have to remember that if I want to build something out of aluminum.