Tips on welding up a shaft

I have a machine at work, I do not have to fix it in the next couple days but
I'd like to
fix it before they decide to scrap it since the production job is currently
running on a
tool room lathe I'd rather not have production near since I use the thing.
Anyway, if I fix it cheap, it stays, production goes back to using it and I'm
happy. There
is a shaft that got loose, wallered out the woodruff key seat and wallered out
the pulley.
The first thought is welding and turning it down.
I can't spray weld we are not equipped so that is off the table. The metal adder
available is a wire feed welder.
The area needing rebuilding is located between two threaded sections. That
makes welding
a bit tricky.
Nevermind, welding isn't looking so great, I'm not that good.
Okay, is 1144 a good steel for making an input shaft for a lathe? It isn't
highly
stressed.
But since I posed the question, how would you build up a shaft where you had to
protect
the threaded sections and build up a damaged key seat. Might as well learn
something. You
only have a wirefeed welder to work with, no spray welder.
Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller
Reply to
Wes
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but I'd like to
ly running on a
I'm happy. There
d out the pulley.
That makes welding
had to protect
earn something. You
Cut a new key elsewhere?
Turn it smooth, bore out the pulley, make a split bushing to fill the space?
jsw
Reply to
Jim Wilkins
Once you touch a welder to the shaft it will bend and not run true. I would try to shrink an oversized sleeve on the shaft and then machine it back to size. Machine the shaft down about .100 under size and true it up first.
John
Reply to
John
I've had to do similar many times. I have welded shafts with the MIG while slowly turning in the lathe. Rather than running beads, I do a series of "Baps" and cool the shaft with a wet rag frequently. If you grease the threads, spatter won't stick as well.
Reply to
Buerste
|
| >I have a machine at work, I do not have to fix it in the next couple days | >but I'd like to | > fix it before they decide to scrap it since the production job is | > currently running on a | > tool room lathe I'd rather not have production near since I use the thing. | > | > Anyway, if I fix it cheap, it stays, production goes back to using it and | > I'm happy. There | > is a shaft that got loose, wallered out the woodruff key seat and wallered | > out the pulley. | > The first thought is welding and turning it down. | > | > I can't spray weld we are not equipped so that is off the table. The | > metal adder | > available is a wire feed welder. | > | > The area needing rebuilding is located between two threaded sections. | > That makes welding | > a bit tricky. | > | > Nevermind, welding isn't looking so great, I'm not that good. | > | > Okay, is 1144 a good steel for making an input shaft for a lathe? It | > isn't highly | > stressed. | > | > But since I posed the question, how would you build up a shaft where you | > had to protect | > the threaded sections and build up a damaged key seat. Might as well | > learn something. You | > only have a wirefeed welder to work with, no spray welder. | > | > Wes | > -- | > "Additionally as a security officer, I carry a gun to protect | > government officials but my life isn't worth protecting at home | > in their eyes." Dick Anthony Heller | | I've had to do similar many times. I have welded shafts with the MIG while | slowly turning in the lathe. Rather than running beads, I do a series of | "Baps" and cool the shaft with a wet rag frequently. If you grease the | threads, spatter won't stick as well. |
Just wrap the threaded parts with fiberglass tapes or some other appropriate protective barriers to weld sparks and spatters.
Reply to
R T Smith
happy. There
the pulley.
something. You
If the issue is the key seat, can you just make a new one on the other side of the shaft?
I once did that on a Chevy 350 crankshaft -- which was still in the engine, still in the vehicle. It'd tossed a harmonic balancer. I made a jig to use with a Dremel. A whole buncha abrasive discs and an hour or two later, working under the truck, I had a nice snug new key seat in the nose of the crankshaft. Broached a new seat in the harmonic balancer, reassembled, no further problems.
Reply to
Don Foreman
Barring that (and it sounds good to me!) how about an oversized key? The hardest part will be figuring out an oversized broach for the pulley, but you're smart.
Didn't old-world millwrights make keyways with a hammer and (presumably well hardened) chisel? I'd like to see _that_ done!
Reply to
Tim Wescott
Rather than buy a new broach I've made several keys that were different sizes on the shaft and pulley sides. It's a whole lot easier to mill a step on the key than to file out a pulley slot.
Filing or chiseling flat external surfaces is easier if the part is clamped between two hardened guides, such as vise jaw inserts.
jsw
Reply to
Jim Wilkins
Yes. They used a cape chisel.
Reply to
Don Foreman
Does it need to be removable? can you get away with JB weld?
Reply to
Newshound
I welded up many compressor crankshafts, both steel and cast, that had torn-out keyways or splines. The damaged metal has to be ground out below the level of the original keyway or spline and then built up. The shaft will bend unless you weld a short bead on one side, then a short bead on the other side, let it cool some then another bead alongside the first, then the fourth alongside the second, and so on. Warpage is minimized this way. After the whole shaft has been built up it's cut down to size and keyed.
Stoody makes a good wire for welding up steel shafts. Can't remember the number; too long ago. 125ksi or so. UTP makes a nickel wire for building up cast iron, and I can't remember that, either.
When welding cast you must keep the part cool, so short beads with plenty of cooldown time is important. Peen the bead as it cools. Use a low amperage so that the cast iron doesn't melt much at all; you want the nickel to stick with minimal mixing to keep it machinable. If it mixes much it'll be way too hard to machine and the cast part will crack easily.
1144 steel is great stuff. Machines easily and has a tensile of about 125ksi. It can replace a lot of heat-treated fittings and the like.
Dan
Reply to
Dan_Thomas_nospam
Take it to place that welds crankshafts. If they do that anymore. They have machines that turn the shaft and weld. I think most submerged arc.
Reply to
Calif Bill
I've heard it is good stuff though I have never tried it. Sometimes refered to Stressproof. Company is buying, might as well have fun in the tool room on a slow day. :) Wes
Reply to
Wes
I just happened to have some fiberglass tape from the days of wiring up heated forming dies. I'm using it tomorrow.
Thanks for the tip. I have threads on both sides of the damaged journal. The less damage I do to them the less recutting I have to do.
Wes
Reply to
Wes

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