Checking a TS using a Surface Gauge (Lotsa Pics)

[Bruce Page]

After reading Mark Stutz’s thread on Dial Indicators for the TS Aligner Jr. I thought I would post some pictures on how I align my table saw using a Surface Gauge (pic#1&2).

To check blade/miter slot alignment I raise the blade and mark a dot on the right side of the blade using a Sharpie. Using my surface gauge with the front pins extended into the miter slot, I push the pins against the slot edge and zero out the test indicator (pic#3). Next, I rotate the blade so the Sharpie mark is on the left and slide the surface gauge to the mark while maintaining pressure against the slot edge (pic#4). If the indicator still reads zero, the blade is perfectly aligned.
Checking the fence is just as simple Pic#5&6).
The gauge can also be used to check the parallelism of a planner or drum sander head to the table (pic#7), set blade height, router bit height, etc (it’s a handy tool to have around).
Pic#8 shows my collection of test indicators with accuracy ranges of .0001, .0005, & .001. Pic#9 is my collection of 1” & 2” travel indicators. :D

[Bruce Page]

The rest of the Pics

[Bill Simmeth]

Very nice pictorial, Bruce. Thanks! Impressive array of gauges (and nice hunk 'o granite, too).

[Michael Ballent]

Bruce, Thank you sooo much for showing us that... I already have the TS Aligner Jr. and really like it. One question, what is the difference between at dial indicator and a test indicator?

[Russ Massery]

Michael, The test indicator is the small one in the first set of pics.

[Bill Simmeth]

Well, Bruce can probably explain it much better, but a test indicator has a point that swivels while a dial indicator has a point that plunges. The way the test indicator tip works visa-vie the plunge tip on the dial indicator is generally much smoother and more sensitive.

[Roy Wall]

Bruce,

Is the plunge indicator showing your fence is .003ish out at the back of the saw?

Is it more accurate to go by the blade (front and back) to two points on the fence-- same idea as the left miter slot.

My questions being I'm not so sure how well the two miter slots are aligned/parallel to one another....

[Mark Stutz]

Thanks, Bruce. Probably old news for many, but very interseting to me. Have never heard of or seen one before. Thanks.

Mark

[Bruce Page]

Bruce,

Is the plunge indicator showing your fence is .003ish out at the back of the saw?

Is it more accurate to go by the blade (front and back) to two points on the fence-- same idea as the left miter slot.

My questions being I'm not so sure how well the two miter slots are aligned/parallel to one another....
Roy, the indicator is showing about .012 out from front to back of the cast iron table. With another 9" of fence extending beyond the table, I have about .018 drift front to back.
The two miter slots on my saw are exactly parallel, (I checked them when I bought the saw several years ago) so in my case, it dosen't matter which slot I use as a datum.

[Roy Wall]

Thanks Bruce!!

I need to see how well my miter slots align!

I use a lower tech method on the miter/blade alignment and the blade / fence alignment - using a combination square and piece of paper:eek: .....and sliding the comb. square within the slots.

Good pics:)

[Mike Cutler]

Very nice pictorial essay Bruce, very informative. I like the use of the test indicator and the surface plate. Ya' missed one important point though... Where do you get them?
Unfortunately I've found that as I get older, my patience and skill have increased, but my near vision has decreased a little. This has made me a bit more dependent on better measuring instruments that have a display of some sort. Something like that surface plate device, and test gauge would be very handy to me.

Machinist's have such cool tools.;)

[Michael Adelong]

I never considered measuring the slots for parallel to each other. As long as things like sleds with 2 miter bars don't bind when you slide them, does it really matter if they are parallel or not?

I use only the right slot for aligning both the blade and the fence. I only use the left slot for my mitre gauge, tenoning jig, and crosscut sled, so I adjust those to 90 degrees individually.

Michael

[Gary Herrmann]

Dang, you machinists have nice measurement tools. I think I did ok with a magnetic base dial indicator, but if I have future problems, I'll have to dig up this thread. Thanx Bruce.

[Tyler Howell]

This Guy means bidness!!!:eek:
Thanks Bruce very informative.

[Kent Parker]

Really nice! Thanks Bruce.

Any place you know of that sells surfaces gauges besides Griz and Ebay?

Cheers,

Kent

[Bruce Page]

Mike, I used a test indicator simply because they are easier to setup and you can get down closer to the center line of the blade, (travel indicators have to be held pretty much perpendicular to the surface that you are checking). Test indicators are also more expensive than the travel type: The Swiss made Interapid that I showed in the pictorial has .0005 resolution and retails for around $235 these days.
You can purchase a Starrett “Last Word” test indicator (sufficient, but not great) for around $100. http://www.mytoolstore.com/starrett/test04.html


Michael, I suspect that both of the miter slots are typically machined at the same time, and therefore should be parallel to each other.


Kent, MSC sells the industrial versions but I think the Grizzly would be satisfactory.

MSC:
http://www1.mscdirect.com/CGI/N2DRVSH?SISHNO=957274&SISRCH=1&SIS0NO=208108&SIT4NO=5354898&SIOR=2 (http://www1.mscdirect.com/CGI/N2DRVSH?SISHNO=957274&SISRCH=1&SIS0NO=208108&SIT4NO=5354898&SIOR=2)

Grizzly Surface Gauge:
http://www.grizzly.com/products/h2713 (http://www.grizzly.com/products/h2713)

Grizzly Test & Travel indicators: (Keep in mind, you do not want the .0001 resolution, they are way too sensative for this application)
http://www.grizzly.com/products/searchresults.aspx?q=dial+indicator&submit.x=5&submit.y=11 (http://www.grizzly.com/products/searchresults.aspx?q=dial+indicator&submit.x=5&submit.y=11)

As you can see by the pics below, a travel type indicator will do the job almost as well.

[Pete Harbin]

Very cool Bruce! Thanks.

Pete