Weld or use coupler?

http://homepage.ntlworld.com/richards_internet/TEMPORARY/DCMOTOR.html
I'm going to lengthen the 1/4 inch diameter shaft by 80mm. It's 11mm long at
the moment.
I can use brass coupling, or the 1/4" extention shaft could be welded. How easy is it to weld the extention shaft on, and it be true? There is not much length, shaft only protrudes 11mm. Now if the shaft protruded 6", perhaps you could use angle iron to align the two shafts. Not sure you can do that with only 11mm protruding.
What would you do, just get a brass coupler because it's so much simpler? TIA.
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Rich wrote:

It is *very* easy to get it wrong. It is almost impossible to get it right, depending on how much wobble you want.
Nick
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I would set the shaht in a collet in the lathe by the other end, run this end in a steady, drill and tap the shaft and screw and locktite an oversize extension to the shaft. After curing I would turn the extension to size. Peter
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I've seen a LOT of motor shafts that have had repairs using heat, ie welding and metal spraying, and they never hold up, even on big diameter shafts. Far better in your case to turn up an extension which fits over the original and is held in place with a grub screw. I certainly wouldn't weld a 1/4" shaft.
wrote:

I would set the shaht in a collet in the lathe by the other end, run this end in a steady, drill and tap the shaft and screw and locktite an oversize extension to the shaft. After curing I would turn the extension to size. Peter
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Okay, folks are telling me, Don't weld that shaft! I will take that advice. Thanks a lot.
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