From: strollo@ssd.kodak.com (Larry Strollo)
Subject: Re: Squaring up a very old table saw.
Organization: Eastman Kodak
Date: Tue, 15 Sep 1992 18:28:39 GMT

In article <1779@shaman.wv.tek.com> scotty@stargeek.wv.tek.com writes:
>
>I have tried to align the blade to the mitre guage groove by loosening the 
>whole under-carriage from the table and adjusting it, but I just can't seem
>to get it right. There isn't enough slop in the holes to allow me to adjust it
>as far as it needs be, and trying to hold it in place while re-tightening the 
>bolts is also a problem. Has anyone else ever had to a re-align the blade on 
>their table saw? If so, what methods did you use? I have access to a mill at 
>work, I suppose I could bring in the parts and mill the bolt holes into slots
>to give me the adjustment room I need, but should that be necessary? 
>Any advice would be appreciated.
>
>

I also reconditioned an old saw (a Henniker, about 40 years old I think).  It
included not only getting the blade parallel to the mitre slots, but also
removing a layer of rust, painting, rewiring for 220, and getting the 1/4" 
steel plate top flattened with a blanchard grinder.  But I digress...  

I am not familiar with the saw you have, but I'll tell you what I had to do 
with mine.  This is too compliated for my skills at ASCII drawing, so I'll
try to describe it.

[NOTE: Before you can accurately do what I did, you have to make sure your 
 arbor is true (i.e. has no run out), and make sure you have a truly flat blade
 (or disc) mounted in it.  If one of those two conditions is not true, it's
 at least part of your problem. 
 About a year or so ago (someone correct me if I'm wrong), FWW had a good
 article on the steps necessary to fine tune a table saw.  Let me know if you
 need the exact issue number.]

The arbor assembly for my saw is mounted on a carriage that slides on a rail.
The carriage slides so that I can have the blade cutting in the center of the
saw table, or at the very back, or at the very front (this last position is 
scary).  The rail is mounted to the saw frame, and there is little or no play 
for an "angular" rail adjustment to get the rail parallel.  However, there are
3 long bolts that hold the arbor assembly to the carriage.  These bolts are 
mounted vertically, and loosening them allows the arbor assembly to be 
adjusted to get the blade parallel to the mitre slots.  There is a total of 
about 3 or 4 degrees of play, which was plenty. 

First, raise the blade as high as it will go without having the arbor hit the
table.  As far as finding the the saw's parallel "G-spot", it was basically a 
trial and error process.  I probably went through about 15 cycles of the 
following steps.  

Loosen the bolts, tap lightly on the arbor FRAME (not the arbor) with 
a light (e.g. ball pein) hammer, tighten the bolts and see if things are lined
up.

I emphasize the word "light" because I tapped too hard 90% of the time.
I used a dial indicator mounted to my mitre gauge to determine if things
were lined up.  Have the dial indicator's tip touching the face of the blade
then push/pull the mitre guage along the mitre slot, watching the needle for 
deflection.  I have never seen a definitive answer as to what's a good number
to shoot for.  Clearly, 0.1" deflection is too much, I would say 0.05" is too,
but is 0.01 ?  It depends on what you're building.  I was able to get it down 
to only a couple of thousandths, which is fine with me.  If you don't have a 
dial indicator, I'd strongly urge you get one, at least for this operation.  
Since you have access to a machine shop, maybe you can borrow one from some 
kindred spirit.  They're delicate & sensitive, so be careful.  

Once you are satisfied that the deflection you've measured is acceptable, 
there's one last step.  That is to cut a piece of wood & check the results.
Sometimes the static setup does not match the dynamic one.  Unless you
are a highly experienced machinist, and also nuts, NEVER have the blade
running during the deflection measurement and adjustment steps.  If the 
dynamic system is unacceptably bad, try to guess at what adjustments to the 
static system will yield what you want from the dynamic.  Fortunately, I did
not have this problem.

Good luck, let me know if I can be of any more help;

LMS


-- 
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Larry Strollo                                             strollo@ssd.kodak.com
Eastman Kodak Co. Rochester, NY 14653-9005                       (716) 253-9822
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