Mitre Jig for the Table Saw

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Blog entry by Grumpy posted 2417 days ago 28753 reads 12 times favorited 11 comments Add to Favorites Watch

This is not a new concept nor is it my idea but I thought is was worthwhile sharing. My son recently wanted to make some frames for his university degree & other certificates. He had a little trouble getting the mitres accurate with the basic mitre gauge for the table saw even though I had made an extension piece for it.
One of Murphy’s laws says that after you do a job you think of a better more accurate & easier way. Murpy is also that pain in the neck that makes you get it wrong if you have only a 50/50 choice, or if there is anything that will go wrong it will. If I catch up with Murphy one day I will give him a bit of lip. Anyway we are right off the track now.
As I said this mitre jig is not my invention. It is fairly simple but consistently accurate if you set it up correctly. It works on the same basis as a T/S cut off sled. You need a flat board with a couple of runners underneath to guide the jig over the T/S surface. I used softwood runners cut to fit fairly snugly in the T/S grooves.


You will need to make sure the front edge of the sled is dead square to the saw blade and remains true when sliding back & forth on the runners. This should not be difficult if you install the runners at 90 degrees to the front of the sled.
Attach the runners then run the front of the sled through the T/S blade only as far as is needed to cut mitres, about 6” is ok for what I need it for.
Next you need to set two mitre guide supports at right angles to each other on the sled. The right angle is critical and the alignment to the T/S blade is also important. I found that a large builders square was handy to establish the right angle between the mitre guide supports. Using the front edge of the sled as a reference you then need to draw a line on the sled at 45 degrees to the front edge at a distance back from the front edge that will accommodate any stock you wish to mitre. (A 3,4,5 triangle can be used here to get accuracy over the longest possible distance to create the 45 degree mitre).
Then screw the mitre guide supports firmly to the sled at right angles to each other and one of them along the line drawn at 45 degrees to the front edge and adjacent to the slot cut by the T/S (boy that was long winded but it is really a simple concept).

Before you set the guides at 90 degrees cut a 45 degree mitre on each one and butt them together.
Lastly, run the front of the sled through the T/S and through the mitre guides. You should now have a perfectly lined up system that will cut accurate mitres every time. Tearout will be minimal because all of the workpiece is supported.
I have added toggles for added holding ability & also quick release.
The advantage of this jig is that provided you have the mitre supports at a perfect right angle all the mitres will be accurate because you use both sides of the jig.
If anyone has any questions I will happy to help out.

-- Grumpy - "Always look on the bright side of life"- Monty Python

11 comments so far

View GaryK's profile


10262 posts in 2621 days

#1 posted 2417 days ago

Great post for anyone looking to make a miter sled.

-- Gary - Never pass up the opportunity to make a mistake look like you planned it that way - Tyler, TX

View Bob #2's profile

Bob #2

3808 posts in 2655 days

#2 posted 2417 days ago

Thanks Grumpy.
We are fast becoming a single repository for all that folks need for sucessful woodworking.


-- A mind, like a home, is furnished by its owner

View newguy's profile


59 posts in 2560 days

#3 posted 2417 days ago

Great idea and very simple. I’ll have to build one for my shop. Thanks Grumpy.

-- Fred, Parker, Colorado

View mrtrim's profile


1696 posts in 2513 days

#4 posted 2417 days ago

great idea grumpy

View cajunpen's profile


14379 posts in 2699 days

#5 posted 2417 days ago

Thanks Grumpy. I have one similar to that and it works like a charm.

-- Bill - "Suit yourself and let the rest be pleased."

View rikkor's profile


11295 posts in 2508 days

#6 posted 2417 days ago

Nicely done “How-to” Grumpy. Thanks.

View ajosephg's profile


1850 posts in 2194 days

#7 posted 2112 days ago

Hi Grumpy
Could you repost the pictures to this project? I might want to build it.

-- Joe

View Grumpy's profile


19393 posts in 2484 days

#8 posted 2112 days ago

Thanks for letting me know Joe, all fixed.

-- Grumpy - "Always look on the bright side of life"- Monty Python

View ajosephg's profile


1850 posts in 2194 days

#9 posted 2112 days ago

I appreciate it.

-- Joe

View degoose's profile


6996 posts in 1988 days

#10 posted 1974 days ago

So simple.. just what I need.

-- Drink twice... and don't bother to cut... @ For lovers of all things timber...

View cabinetmaster's profile


10874 posts in 2191 days

#11 posted 1974 days ago

Good job Grumpy…..................

-- Jerry--A man can never have enough tools or clamps

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