# How to align dial indicator with table saw miter slots?



## Vrtigo1 (Mar 18, 2010)

I have a dial indicator with a magnetic base, and am looking for the best way to accurately measure distance to the blade and fence from the miter slots. The magnetic base is no good because I have to move it from the front of the table to the back, and will never be able to get it in the same position.

Most magazines articles that I've read use some type of cast aluminum jig that rides in the miter slots and has a spot for the dial indicator to attach.

I've also seen some people online that just use a strip of hardwood to ride in the slots and then attach some sort of wooden jig to it in order to mount the gauge, but I wasn't sure if this would provide enough accuracy.

Which method do you use? If you bought a jig, which one is it and where did you get it?


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## BrandonW (Apr 27, 2010)

Take a thin metal plate (maybe you have some scrap around) and attach it to a 3/4 strip to fit into the miter slot. The magnetic base of your dial indicator will attach to the plate and you can slide it up and down the miter slot.


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## TheWoodNerd (Aug 30, 2009)

Attach a piece of wood to a miter gauge, then attach the DI to that.

If (like me) you buy a nice aftermarket gauge, you can just leave the DI on the original one for occasional checks. The same rig can be used to check your fence alignment.


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## Vrtigo1 (Mar 18, 2010)

I saw the TS Aligner, but just didn't think it was worth the price at this point since I already have a dial indicator, and would really be spending $130 for the aluminum bracket. The miter gauge route looks to be a good suggestion, and I think I'll give that a try as well as trying just a strip of oak to ride in the slot with a board on top to mount the gauge on, then see which of those two methods is more accurate. Thanks!


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## SCOTSMAN (Aug 1, 2008)

that can be done much cheaper than $130 bucks.Alistair


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## Vrtigo1 (Mar 18, 2010)

Alistair I think you misunderstood me. The $130 I referenced was the retail price for the TS Aligner Jr jig, as linked above. It seemed to me that I ought to be able to find a simple aluminum jig that rides in the miter slot and has a spot to attach a dial indicator for about $15-20, but I guess I underestimated the cost of machined aluminum!


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## mnguy (Feb 4, 2009)

I suggest when you are using the miter gauge or wood strip method to always push the base for your dial indicator firmly to one side of the miter slot, the same side each time. This will help reduce errors attributable to any slop between the miter gauge / wood strip and the slot.


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## Jim Jakosh (Nov 24, 2009)

Brandon and thewoodnerd said it about the simplest. That will work with the least effort building anything


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## ajosephg (Aug 25, 2008)

I bought TS Aligner Jr. and consider it one of the best purchases I've made for the shop. It is much more than a piece of machined aluminum.

Several benefits:
It can be easily adjusted to take the slop out of the miter slot so you can make measurements hands-off.

It has many uses besides blade to to fence, blade to miter slot. For example blade angle, miter gauage alignment, fence perpendicularity, jointer blade height, and jointer fence perpendicularity to name a few.

Sure you can make shop jigs to do this, but TS Aligner Jr. will do it better. I'd rather be cutting wood than messing around with jury rigged stuff.


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## jcwalleye (Dec 26, 2009)

Here is a dial indicator setup I use: It also works pretty good checking the fence to mitre slot alignment


















Removing the mitre block and clamping the opposite end to a drill bit (actually a centering pin), lets me check how square a drill is to the drill press table.


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## TheWoodNerd (Aug 30, 2009)

"To much slop in the miter gauge to work adequately"

Depends on the miter gauge and how you hold it. The cheap one that came with my saw has spring-loaded ball bearings on one side that keep it tight. All you have to do is not push it the other way.

I'm all for buying expensive gadgets. I have a Festool T15 drill, so I'm not adverse to spending money. But $150 for a gadget you'll use very rarely seems over-the-top when a $20 DI and a plywood scrap does the job just as well and just as easily.


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## Vrtigo1 (Mar 18, 2010)

JC, that jig looks just about perfect for what I need to do. I think I'll make one of those tonight and give it a shot. The only modification I think I'll make is to widen the base a bit to make sure it doesn't tip.


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## BrandonW (Apr 27, 2010)

Here's the system I use:



















I have a strip of UHMW that fits in the miter slot snug enough so that there's very little side-to-side movement, but can still be pushed up and down the miter slot. Attached to it is a 3/8 sheet of Baltic birch ply and a strip of maple to which I fixed the dial indicator. The birch ply gives a nice stable base.


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## jimhester (Oct 25, 2009)

Jcwalleye and woodnerd…........both those setups look good. I have yet to buy a dial indicator, so I don't know how to attach them to anything. How did you guys attach the di to the wood? Thanks, Jim


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## timbertailor (Jul 2, 2014)

I use this one. It is self aligning. Genius!

You can get it here.


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## jcwalleye (Dec 26, 2009)

The back of my dial indicator has a plastic ring molded into it for securing with a bolt. I simply cut a slot in the arm to fit the ring and bolted it to the arm which is attached to another piece that fits into the miter slot. On the other end of the arm, I drilled a slotted hole that allows me to attach it to the centering pin I got with my drill press for aligning the drill press table. The same dial indicator serves both purposes fine.

Regards


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## MrRon (Jul 9, 2009)

Save all the money and use your combination square. Place the head in the table slot and extend the blade until it touches a tooth at the front. Then rotate the blade backwards and move the square to meet the same tooth. Adjust the trunnion bolts until the combination square blade touches the same tooth equally front and back. Adjust the fence using the same combination square method. $130 for an aligner! REDICULOUS.


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## jimhester (Oct 25, 2009)

MrRon…......I have to agree. On my budget, a tool would have to do a lot more than align the blade to spend that kind of money on it. I did the combination square method last night and I think I got it pretty close. The reason I'm trying to be as exact as possible is that in cutting 3/8" box joints, I'm getting a slot that is about 1/32" wider than I should. On my better saw, it comes out exact, but I'm trying to set this saw up as a dedicated box joint unit. It's a lot better use of my budget to keep finagling with the adjustment until it's right.

My wife asked what I wanted for Christmas, and I told her a dial indicator. But it would have to be a cheapy, for no more actual need that I have for it. There are other applications, but I think an HF for $12 with a shop built jig will suffice nicely. Thanks for the suggestion.

And to jcwalleye…..Thanks for the info on how to mount the di onto a wooden jig.

Thanks to all who have helped me on this. Jim


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## TheFridge (May 1, 2014)

Ebay. I got a .001 and a .0001 starrett indicators for 50$.

Ehh. You can guess it's right. Or you can know it's right.

Planer/ jointer knife setup. Can't measure arbor runout with a square.

Tekton makes a cheap (15$ or so) indicator, and with measuring tools you get what you pay for new.


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## dogmir (Dec 31, 2012)

I have one of these I picked up last time I was at Rockler. I just use it with digital caliper I already had. Its cheap but works.
" 
Link


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## jimhester (Oct 25, 2009)

TheFridge and dogmir…........thanks for the tips. That miter base looks good. Using it with a digital caliper would be a big help. And ebay for indicators is something I hadn't thought of.

I used the combination square method and got close. But my vision isn't too good, and every time I would think I had it, it was still a little off. I was wishing I had a big flat plate with a 5/8" hole in the middle when I remembered that in one of the many boxes my Dad left me was a 10" sanding disk attachment that I thought I would never use.

I laid it on my table saw top and it was totally flat as far as I could tell. I mounted it in the saw, and it was a lot easier for me to see when easing the square up on it than trying to get the exact point of a tooth. I was able to get closer, within about 1/64" over on a 3/8" slot using the Freud box joint cutter set. But I'm going to keep at it. Thanks again, everyone.


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