# How to Cut Miters on Radial Arm Saw?



## minuteman62-64 (Mar 15, 2012)

Looking to improve the quality of my miter cuts. The tool available is the good old RAS.

So, I need to miter some edging, 3/4" thick x 2" wide. The miters will be across the 3/4" dimension (as in base molding, not as in a picture frame). 

Will I get the best miter by using one of those jigs, that allows cutting a 45 with a 90 pull, with the long dimension of the piece positioned vertical? Or by rotating the yoke to the 45 degree position and laying the piece on the table with the long dimension horizontal?


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## Dave Paine (May 30, 2012)

minuteman62-64 said:


> Looking to improve the quality of my miter cuts. The tool available is the good old RAS.
> 
> So, I need to miter some edging, 3/4" thick x 2" wide. The miters will be across the 3/4" dimension (as in base molding, not as in a picture frame).
> 
> Will I get the best miter by using one of those jigs, that allows cutting a 45 with a 90 pull, with the long dimension of the piece positioned vertical? Or by rotating the yoke to the 45 degree position and laying the piece on the table with the long dimension horizontal?


Some RAS have more flex than others. I have an early 80's model which did flex more than I wanted.

I would bevel the motor so you are cutting through only 3/4in thick material.

You may need to tweak the setting. The detent may not be as accurate as you need.

Do a test cut on some scrap of similar thickness. Make two pieces and cut one, then flip the other piece top to bottom. Then fit them together and check how close you are to 90 deg. Adjust the bevel as needed. Make another couple of test cuts.


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## woodnthings (Jan 24, 2009)

*build the jig*

You will get better results with a fine tuned jig than trying to set the arm over to 45 degrees. The arm may not lock exactly and is not easy to adjust out of the "lock" notch/detent. Use a draftsman 45 degree triangle to set your fences on the jig. Make one end a little loose for fine adjustments and pivot on the other end.
You can register your fences off the kerf you make at 90 degrees rather than the blade.

Some ideas for adjustable fences on this sled/jig:
http://www.woodworkingtalk.com/f27/table-saw-sled-build-49218/


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## cabinetman (Jul 5, 2007)

If your arm is set up for a very good 90 degree cut, make a jig to position the piece at a 45. Of course, if your piece is 12' long and you need to miter one end, and you don't have room for the free end, you'll need to make other arrangements.:yes:








 







.


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## Fred Hargis (Apr 28, 2012)

To some extant it may depend on what saw you have, as well as how you have it set up. If you have long tables on both sides of the saw, swingint the arm may be easier. My Dewalt can do it either way, and the cuts and accuracy are about the same. But for ease of use, it's often easier to set up a jig and keep the saw arm at 90º. At least it seems easier to me to do it that way. Cabinetman brought up a good point....really long pieces require some extra work to support them. If they sag at one end, it may throw off the cut at the saw.


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## minuteman62-64 (Mar 15, 2012)

Thanks, guys. Based on input it seemed best to set up cut with saw in normal 90 degree position and use a jig. My concern was that the blade might "wander" cutting through the long dimension.

Re-built my jig (attached photo) to provide taller, more supportive guides, paying particular attention to getting the guides square to the platform.

Results - scrap pieces just loosely set against the table edge were plenty good enough for what I'm doing, positioned either right side up or turned upside down (meaning no appreciable blade "wander").


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