Getting Mixed Up With Home Stir Welding

Most processes designed to join two pieces of what-have-you together are consumptive of something, whether it’s some material acting as a third party to work piece and the tool, or the tool itself. In the wonderful world of friction stir welding, the material of the two pieces under union gets swirled together through friction as the tool traverses the join path. There are, of course, professional machines that perform this with relative ease, but with a large amount of beer on the line, [skookum_choocher] was determined to make his own.

In the first video, he machines a friction welding tool by shaping a tungsten carbide button from a drill bit using a diamond grinder. Once he has a rough shoulder and protuberance going, it’s time to let her rip.  Despite issues with clamping and the geometry of his tool, the weld is ultimately successful at the tail end.

Undeterred, he has another go at it after making some adjustments to the tool shoulder, changing the belt on his poor old Bridgeport, and increasing the clamping strength by a factor of four. You clamp sixteen tons, and whaddya get? A slightly better butt weld than the first time, it turns out. Fearing this weld is insufficient to win the bet, he goes for the lap weld with the work pieces stacked together in a sandwich. We prefer pizza with beer, but nevertheless congratulate him.

Part One


Part Two

16 thoughts on “Getting Mixed Up With Home Stir Welding

  1. Most entertaining. And I have a new phrase to use describe half the gear in my lab, “home fabricobbled tool”. And those metal spalls are called magic pixies. Lol.

    1. There are 2 (or more) types of friction welding.

      What [Fran] did, and what [Scorch] did, is “Friction SPIN Welding”. Spin. . That’s where you use the heat from friction to create a molten puddle and then weld with it. Not just for plastic, you also see it used for joining big pipes and such.

      This is different. This is “Friction STIR Welding”. Stir, not Spin. Instead of welding by heat, it welds by mechanically smashing bits on either side together, creating a sort of alloy, mechanically. Like a microscopic version of those round rainbow jello-whippedcream things from the grocery store with the wavy texture. You know the ones.

    1. I watched this the other day too… if you look closely… the oval motion is only right at the start and end. In between it just moves in a straight line. I think the initial scoop is just to make sure you’ve engaged particles from both sides.

  2. The biggest fault I can see here is the shape of the tool and the rotation speed of the tool. But he is on the right track and entertaining us to boot. I rate 5 hard ons out of 5.

  3. “here are, of course, professional machines that perform this with relative ease, but with a large amount of beer on the line, [skookum_choocher] was determined to make his own.”

    haha lol, thats the way it goes: alot of beer.

  4. NASA is starting to do this with their next generation rocket fuel tanks. Of course, they’re the size of a house and require a multimillion dollar facility, but it’s awesome to know it’s something that can be replicated at home

  5. [skookum_choocher] has been previously featured as [Chris] at least once, and I think also as [AvE] or [Arduino versus Evil], which are things he has named his channel (Arduino vs Evil is the name ca. his 100-ton screw press “Lil’ Screwy”).

    Maybe all his stuff should be associated with tags? He’s consistently entertaining and educational enough that I’m now a Patreon supporter of his to the tune of $5/mo.

  6. There’s at least one company making aluminum livestock trailers where all joins are done with FSW, essentially making the main body and frame of the trailer a single piece without conventional welds, rivets, bolts, screws or other fasteners.

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