I Lathed!

mike837go

mike837go

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Yesterday, my first machining project went nightmare on me.

As I was assembling the new parts with the reusable parts and the refurbished parts.....

I discovered one of the refurbished parts was actually faulty. I should have tried to position the shaft properly when sizing things up last week.

There was a worn down section in the 1.25" shaft (the worn area measured 1.182" and appeared to have properly machined shoulders).

So I cleaned the worn area smooth and chamfered the shoulders. Then found a piece of scrap that I curled and fitted it into the grove. I TIG welded the scrap into the grove while still in the lathe.

After it cooled a bit, I reduced the diameter of the filler and the scrap so that the bearing and collar would slide over and lock in place.

An extra 3 hours when I thought I'd be done in under one.
 
coolidge said:
So basically you describe what happens on virtually all my projects. ;)
Click to expand...

Ummmm, yeah, sorta....

Unforeseen problems and delays are part of life. But this was an excessive delay based on not seeing what was right in my hands!

Using the lathe and welding and then using the lathe again, is fun. No bout-adoubt that. Just frustrated that it took so darned long.

When I quit for the day, the whole transmission was assembled and ready to hang on the tractor.
 
Congrats on getting it done. Now I have a question, I would be a little scared to do any welding on my actual lathe without a lot of protection for everything. My luck something would spit and put a nice bad spot on my ways or something. But then again my luck is so bad if there are 2 of us in a drawing the other guy will always win.
 
Congrats on your first job done
I never weld in my lathe
I have work at place that did not care if any welded in the lathe but welding may damage the spindle bearings

Dave
 
I understand your concerns about welding on a workpiece while chucked in a lathe. I kept it there since I had to weld all the way around the shaft. Twice. Weld both edges of the patch, turn the chuck, weld... repeat...until done. The tool post really helped to steady my torch hand.

If you recheck my original posting, you'll notice I dragged over the TIG torch.

I was running 85 amps and using as little filler as possible. No drips or sparks flying. TIG is just soooooo wonderful:)! Until you dip the tungsten.:burned up:

The rest of the workpiece never got too hot to hold.

Thinking about it now, a damp rag draped over the shaft at the chuck end and a piece of sheet metal over the ways would have totally eliminated any risk to the lathe.

There's a sheet metal project: A set of 4" covers to drape over the ways with a couple of 2" so the carriage can be positioned anywhere. Then a set to go over the crossfeed & carriage.

------------------------

This fall or winter the 3 shafts for the blades will be given similar treatment (filler only, no patch). The grease seals (or grit & water on top of them) have worn grooves/pitting into them.
 
The risk might come from a poor grounding practice, resulting in possible arcing in bearings. As you mentioned, tig welding does not produce spatter, so protecting the ways is not the real concern. I have mig welded on the plate roller, but the ground clamp is serviceable and next to the hot work (on the actual plate not on the machine). Always ground the work piece and not the machine. I have not welded on the lathe, but have used positioners in the past.
 
Sending welding current through bearings is an absolute NO! in my book. Other than the potential for damage to the bearing, the oil film that the bearing needs to operate properly, is an insulator.

I was trained as an electronics technician, so I can spot poor circuits easily.

When I welded the piece on Sunday, the ground clamp was right on the workpiece, 3" from where I was welding. Nice clean steel, near the weld zone.
 
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