# Cutting miters on the Radial Arm Saw



## DEWALTgwi (Sep 28, 2020)

This is a simple and quick method to cut miters and even sprung crown moldings with the Radial Arm Saw.

Some time back I saw a plan for what was called a *Flying Wing Jig*, it looked interesting so I recreated it. It was very accurate, the problem was that it wasn't exactly portable, it was heavy, hard to store and time consuming to setup. So I came up with an alternative, which is light weight, easy to store and very quick to install and uninstall.

On a Radial Arm Saw the are about three or more methods of accurately cutting right and left miters, *The Broken Fence Board Method, The Flying Wing Jig and mine the Modular Wing Jig.*

I trust that most people are familiar with the BFB method. The Flying Wing Jig was developed by Wally Kunkel of the Mr. Sawdust fame and my Modular Wing Jig.

Included are pictures of the Broken Fence Board method, the Flying Wing Jig and the Modular Wing Jig.

Below is the Broken Fence Board
















Below is the Flying Wing Jig.









Below is the Modular Wing Jig









Below is the Flying Wing Jig hung on the wall. 









Below is the Modular Wing Jig, packed up and ready for storage


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## KTNC (Sep 12, 2017)

Hi DEWALTgwi:

Your modular wing jig looks pretty practical. Have you found that you can make perfect 90 degree corners using it?

Looks like those blue things and clamps are store bought and the rest is home made. I don't think there's quite enough info in the picture for me to build it. Care to provide some more details and color commentary?

regards, Kerry


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## 1thumb (Jun 30, 2012)

> Looks like those blue things
> 
> - KTNC


Thems be speed squares


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## LesB (Dec 21, 2008)

I'm sure it work well but that is a big jig to have to store…..unless you cut a whole lot of miters.

Craftsman use to make one of these and you can still find one on Ebay. I think I threw mine out year ago. At the time it seemed easier to swing the arm of the saw 45 degreesI' and tweak the settings than set that thing up. One of the biggest problems with radial arm saws was keeping them properly aligned.


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## DEWALTgwi (Sep 28, 2020)

> Hi DEWALTgwi:
> 
> Your modular wing jig looks pretty practical. Have you found that you can make perfect 90 degree corners using it?
> 
> ...


Thank you for your interest.

I'll post various shots of the jig, it's pretty self explanatory.

I made mine from Baltic birch. Each wing is made up of a 1/2" piece at 30" long and the vertical piece is 3/4" thick and 24" long.

Along the base at 3/4" I cut a groove to fit the thickness of the rafter square.

Then using screws at least 1 1/4" long, countersink and fasten the fence to the base, forming a 90 degree angle. Be finicky about the piece being flush on the bottom where they form the 90 degree angle.

With the square holding the base trim the ends to 45 degress right and left.

Now fasten the squares to the base and trim the ends.

Now to answer you question about the accuracy, ...it's 90 degress, "airtight"

On a DeWalt with a 10" blade you can accommodate just under 3" wide material, which means shadow boxes 3" wide, Crown moldngs sprung ot 3" and so forth.

The advantages are apparent when you start using it. It sets up in less than a minute, the saw's fence doesn't have to be removed as the jig clamps directly to it, with the "Flying Wing Jig" you not only have to remove the saw's fence but you have to crank the saw up about a dozen turns to accomodate the table thcikness. My jig slso, stores easily on a shelf.

Also the quick setup is great when you realize that you have one more 90 degree cut after you put your jig in place.

Then you can also do sprung moldings if you're doing crown moldings.

Tipped on it's side to show the fitting of the rafter square.









The end where its trimmed.









Showing how the square nut holds the rafter square flush to the fence,









The triangular reference pieces are set in place to provide the angle needed for the sprung molding. I just pin nail them to the table and remove them when not needed.









Cutting the opposite(complimentary angle), nestled into the stop block.


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## KTNC (Sep 12, 2017)

> With the square holding the base trim the ends to 45 degress right and left.
> 
> Now fasten the squares to the base and trim the ends.
> 
> - DEWALTgwi


Hi DEWALTgwi:

Thanks for your helpful comments and pictures.

I'm starting to understand it. Looks like "speed square" and "rafter square" are synonyms?

Is this 12" Swanson speed square for $8 on Amazon a good one to use for the jig?

https://www.amazon.com/Swanson-Tool-T0701-Speedlite-Structural/dp/B0008JF0TE/ref=sxin_10_ac_d_rm?ac_md=4-2-cmFmdGVyIHNxdWFyZSAxMg%3D%3D-ac_d_rm&cv_ct_cx=rafter+square&dchild=1&keywords=rafter+square&pd_rd_i=B0008JF0TE&pd_rd_r=78fdd82a-dd9b-4817-9f5f-44d1c92e6360&pd_rd_w=ic8X4&pd_rd_wg=xo4uE&pf_rd_p=b0625ac1-ea22-4a1c-8206-57129b08e075&pf_rd_r=C879RTJX6N1EE9BZPWC7&psc=1&qid=1616973305&sr=1-3-12d4272d-8adb-4121-8624-135149aa9081

I'm not getting your second picture in the post above. It looks like the blue material sticking out from the rafter square would be right in that channel where you need to run the blade. Does the rafter square itself get cut?

regards, Kerry


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## DEWALTgwi (Sep 28, 2020)

> With the square holding the base trim the ends to 45 degress right and left.
> 
> Now fasten the squares to the base and trim the ends.
> 
> ...


If you don't nibble the ends off it won't be flush with the base, this is critical for the jig to align with the fence. Just make sure that the clamp you choose can fit in the slot tha that holds it against the fence.


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## Bstrom (Aug 30, 2020)

Good to see another DeWalt RAS user - I have three and use them regularly.


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## Chip201 (Sep 19, 2021)

Curious to see cutting setup. Do you get set to make both cuts at same time with both wings in place or work one side and then the other,
Also why you chose 1/2"and 3/4"boards and not both using 3/4. Last construction question is the square nut usage in the slot. I almost suggested a wood spacer to go in slot and put a screw through that.


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