[SEL] RE: Pitted shaft & Babbitt bearings

[Andy Glines]

Curt, I have yet to think that one of your ideas is dumb so I have no 
intention of deleting this.  I never really thought of replacing the shaft.  
A 3" (checked last night) shaft about 54" long complete with keyways, 
machined bearing surfaces, threaded holes.... could get a little $$$ though. 
  This shaft is serviceable just needs to be a little slicker.  The shim 
stock on the O.D. idea is pretty creative and I'm going to keep that one in 
my bag of tricks.  Where do I get stainless shimstock?  I've never seen beer 
sold in a stainless can??  The dummy shaft solution is looking more & more 
attractive all of the time.  I'm going to have to eat my words about the 
castings being easily removable.  I should know better than to use the word 
"easy" when refering to a 100 year old machine.  I'm not familiar with "DOM" 
tubing.  What does DOM mean?

>   25. Re: RE: Pitted shaft & Babbitt bearings
>Message: 25
>Date: Thu, 21 Apr 2005 15:41:33 -0400
>From: Curt <curt at imc-group.com>
>Subject: Re: [SEL] RE: Pitted shaft & Babbitt bearings
>To: The SEL email discussion list <sel at lists.stationary-engine.com>
>Message-ID: <426801ED.5090600 at imc-group.com>
>Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
>OK Andy if you think this is a really dumb idea then just delete it.
>I gather the reason you've decided to not replace the short jackshaft is
>cost??? Since you are concerned about filling in the pits (I'd blast and
>use titanium Devcon) and have learned that JB won't take the pre-heat
>for babbitt pouring. How about this.
>
>Before filling the pits, carefully cut and wrap the shaft with a piece
>of .003 or .004 thick stainless shim. Have it extend and inch or more
>beyond the bushing area and use a pair of hose clamps to hold it in
>place. You might have to use thinner material and do a couple of wraps
>to get it to lay flat. The idea is that you will have a super slick
>surface to pour against and this will also build in the proper running
>clearance.
>
>Once you've poured, then you can remove the shaft and stainless shim
>stock, sand blast the pits in the bushing portion of the shaft and use
>the titanium Devcon. You may have to enlist the help of a friend with a
>lathe to finish the Devcon. It is damned tough stuff. A file isn't real
>effective!
>
>I have no experience using stainless as a babbitt form and only toss it
>out there as a possibility.
>Curt Holland
>Gastonia, NC
>P.S. Could you use a piece of thin wall 3 1/2" DOM tubing as a dummy
>shaft for pouring? That should be cheap enough.....
>
>
>Andy Glines wrote:
>
> > As usual, I get some great ideas when consulting ATIS lists for
> > ideas.  There have been several good ideas given.  I'm afraid that
> > leaving the pitts alone simply won't work.  The pitted area is
> > actually a strip about 1.5" wide for the length of the bearing surface
> > on both ends of the shaft.  I'm thinkg that this is where rain water
> > got in through the oil troughs and sat on the shaft.  Besides the
> > rusted strip the shaft is pretty smooth.  Leaving this area alone will
> > result in a big gap in the bearing surface that I think will cut the
> > bearing quickly.  When I first posed this question I thought that the
> > bearing castings were permanently attached to the boiler.  Further
> > investigation shows that they can easily be taken off where I can put
> > them on a table.  Being able to take them off means that the dummy
> > shaft might work well.  Of course I've gotten some links to higher
> > temp fillers.  Arnie asked what size the shaft is... 3.25" or 3.5"
> > about 54" long.  I had already considered his idea that a shaft of
> > sufficient size could act as a heat sink and therefore the filler
> > would only see the extreme heat for a short time.  I'm pretty sure
> > that this shaft is big enough.  As always you folks have give me food
> > for thought.  Thank you!
> > BTW The shaft in question is the countershaft that drives the wheels
> > on my Huber steamer.
> >