# Quick Question on cut width of a bit



## fstellab (Oct 12, 2012)

*Folks,

I am trying to cut some Dado's for the runners of a table saw sled.
I got my issue with cutting straight dado's fixed, basically it was just a lot of practice and I got a new Craftmans Plunge router with LED lights. The new router is 1/2 the weight of my other beast, and the lights help a lot. The new craftsman has a nice smooth plunge movement as well.

Now my issue is the size. I purchased a Rocker 1/2" shaft straight plunge bit. The specs said it has a 1/4" cut diameter; when I cut a dado, it is smaller then 1/4".
Not by much, but a "off the shelf" slider or T-Track does not fit. Then I have to run another cut which allays winds up wider then I want.

Is this unique to this bit ? or something else ..

Thanks - Fred*


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## Quillman (Aug 16, 2010)

Commonplace.
Few cutters are better than + or - .005 on the cutting dimensions.
Shanks are tight but not the rest of the cutter.
What to do? Always duplicate the intended cut on scrap before wrecking good stock.
Learn to measure precisely so when checking the scrap you know what the net dimensions will be on the work.


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## Chris Curl (Feb 13, 2012)

What Pat said.

Many of the cutters I measure with my caliper are 5/1000 small or smaller. They are usually not much more than 10/1000 off. I rarely come across ones that are larger than their advertized size.


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## Seasoned Oak (Jun 11, 2012)

I made a dado jig that uses the stock to set the dado width. I beleive it is shown on the Wood Whisperer.


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## cagenuts (May 8, 2010)

Another reason to use guide bushings.


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## Shortslvs (Jan 13, 2013)

I was going to say the same thing about "The Wood Whisperer". He did a video on an adjustable dado jig. Looks like the way to go.


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## Willway (Aug 16, 2012)

Hi Fred, an easy way is to take a second cut without moving anything (edge guide or table settings) this usually solves this problem for me.


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