Alignment of worktable with powerhead

jmilligan · Post by **jmilligan** » Thu Sep 24, 2009 12:26 pm

I have watched the critical alignment video where Nick aligns the miter slot on the worktable using a depth guage to a marked tooth on a saw blade. Doing this on a saw blade with carbide tips is tricky working down to 1/1000 to 2/1000. I seems to me it would be easier and potentially more accurate to do the same alignment process using a mark on the sanding disk. Any thoughts and experiences??

Ed in Tampa · Post by **Ed in Tampa** » Thu Sep 24, 2009 12:46 pm

When I bought my Shopsmith the procedure was to use the sanding disk. In fact in my Shopsmith manual that is how they show it being done. I have done it both ways.

dicksterp · Post by **dicksterp** » Thu Sep 24, 2009 1:21 pm

I use a Master Plate as I got funky readings with the sanding disc.

dusty · Post by **dusty** » Thu Sep 24, 2009 1:57 pm

jmilligan wrote:I have watched the critical alignment video where Nick aligns the miter slot on the worktable using a depth guage to a marked tooth on a saw blade. Doing this on a saw blade with carbide tips is tricky working down to 1/1000 to 2/1000. I seems to me it would be easier and potentially more accurate to do the same alignment process using a mark on the sanding disk. Any thoughts and experiences??

It is tricky trying to use the edge of a carbide tip as the landing point for the dial gauge. I used to try to use a pointed tip on the dial gauge but no more. For the very reason you mention, I now use a tip that is flat on the end. This flat spot then engages the edge of the carbide that protrudes the farthest. This becomes the point of reference and must be marked somehow so that the same tooth is used for every measurement.

If you really want to, you can tediously tweak the alignment right down to .001" or .002". However, there is enough uncontrolled movement in the carriage that you will probably not retain that level of accuracy. I have come to settle for .003" - .005" during the alignment and don't concern myself with the results of unwanted movement thereafter.

keakap · Post by **keakap** » Thu Sep 24, 2009 9:28 pm

Seems to me the sanding disc is easier, IF one has a bare disc available. But since that may not be the norm, a blade can serve the same porpoise, albeit at a smaller diameter, using the body and not the tooth (odds are decent that the high spot of the body will be in the near vicinity of a high tooth).

But considering Dusty's excellent point re carriage movement, and including fence position as well as any Aux and/or Ext table connections that could effect the relationship, my last check before cutting something I care about is to turn the saw on and run a scrap, with the miter gauge or fence-- whichever is in question-- thru, positioned so that it just barely is touched by the blade, just enough to make noise. If the sound is about the same at the front as at the rear, I'm good.
If it makes noise at the front but not the back I may take a closer look, or do the same test from the other side.
If it starts to make more noise at the rear-- STOP!

charlese · Post by **charlese** » Thu Sep 24, 2009 11:32 pm

dusty wrote: I have come to settle for .003" - .005" during the alignment and don't concern myself with the results of unwanted movement thereafter.

He! He! I really don't know if I should believe that statement at face value. The "don't concern myself" is ????:D

Aw! - Just kidding!

This jibe is brought to you from Jackson, WY

foxtrapper · Post by **foxtrapper** » Fri Sep 25, 2009 6:35 am

Like Dusty pointed out, there is too much slop for such fine tolerances to be worthwhile or consistent or repeatable.

Sawblades have more flex than a sanding disc. If you're being ham fisted, you'll get very screwy readings with a blade as a result.

Remember, you've got to keep measure the same location. Not near the same area, not a similar location, the exact same location.

dusty · Post by **dusty** » Fri Sep 25, 2009 6:51 am

charlese wrote:He! He! I really don't know if I should believe that statement at face value. The "don't concern myself" is ????:D

Aw! - Just kidding!

This jibe is brought to you from Jackson, WY

That's OKAY. I understand.

I trust that the next time I go for "dead on" you'll remind me!

OH, BTW - the next time might not be too far away. I've been thinking about how one might incorporate a micro adjustment to position the table while doing this alignment. It is relatively easy to get the miter track close to parallel to the blade. The hard part is making that minute adjustment to get it dead on. A micro adjuster just might work better than my calibrated fist.

keakap · Post by **keakap** » Fri Sep 25, 2009 2:29 pm

Seems to me the sanding disc is easier, IF one has a bare disc available. But since that may not be the norm, a blade can serve the same porpoise, albeit at a smaller diameter, using the body (a dot with a Sharpie marker) and not the tooth (odds are decent that the high spot of the body will be in the near vicinity of a high tooth).

But considering Dusty's excellent point re carriage movement, and including fence position as well as any Aux and/or Ext table connections that could effect the relationship, my last check before cutting something I care about is to turn the saw on and run a scrap, with the miter gauge or fence-- whichever is in question-- thru, positioned so that it just barely is touched by the blade, just enough to make noise. If the sound is about the same at the front as at the rear, I'm good.
If it makes noise at the front but not the back I may take a closer look, or do the same test from the other side.
If it starts to make more noise at the rear-- STOP!

dusty · Post by **dusty** » Fri Sep 25, 2009 5:38 pm

jmilligan wrote:I have watched the critical alignment video where Nick aligns the miter slot on the worktable using a depth guage to a marked tooth on a saw blade. Doing this on a saw blade with carbide tips is tricky working down to 1/1000 to 2/1000. I seems to me it would be easier and potentially more accurate to do the same alignment process using a mark on the sanding disk. Any thoughts and experiences??

Yes, doing it on the carbide is tricky but I think there might be a way around that problem. It is rather easy, get rid of the carbide.

You can see what I mean in these shots.

[ATTACH]6061[/ATTACH]

[ATTACH]6062[/ATTACH]

[ATTACH]6063[/ATTACH]

[ATTACH]6064[/ATTACH]