# Mitre joint



## Jiroma (Feb 18, 2010)

Hi all, I am trying to make a small pedestal table and the base will be a square made up of 4 pieces mitred. In an attempt to make them perfect I taped my 4 blanks together and cut the mitres using my sliding chop saw. Using a metal triangle to check my saw was set at 45degress I cut my mitres all 4 at once. When I brought them to the bench to put together I find that they are disapointingly out a bit. If I fit 3 peices together neatly (nice joints ) the 4th peice has a gap of about 3/16 ( not so nice). 
What am I doing wrong ?

Jiroma


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## Stick (Aug 23, 2007)

It's not you... it's the alignment of the saw. A framing or speed square isn't necessarily square for sure. To get a chop saw aligned just right takes quite a bit of work and precision squares.


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## cabinetman (Jul 5, 2007)

Stick said:


> It's not you... it's the alignment of the saw. A framing or speed square isn't necessarily square for sure. To get a chop saw aligned just right takes quite a bit of work and precision squares.



I agree. If the initial cut is off by anything...multiply by 4. One way you might try is to pick up a good plastic drafting template...45, 45, 90. They are cheap and very likely right on. Once the saw is set for 45, check two different cuts to see if they align to 90.

Many saws have a slight play in the notch settings.


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## jlord (Feb 1, 2010)

Agree your saw needs adjustment. Should be easy fix.


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## TimPa (Jan 27, 2010)

remember when checking your saw to check on the 'plate' of the blade, and not include any teeth. and, what you are doing is an excellent method for showing the saws error and adjusting the stops.


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## Jiroma (Feb 18, 2010)

Thanks guys. It seems the more I want to do in the shop the more work I have to do to the tools. Not just adjustments but learning how to use them properly. 

Jiroma


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## Rob (Oct 31, 2006)

Jiroma said:


> Thanks guys. It seems the more I want to do in the shop the more work I have to do to the tools. Not just adjustments but learning how to use them properly.
> 
> Jiroma


Yup, we've all been there. The perfect miter is an elusive animal. It will try the best of nerves and patience.


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## Al B Cuttn Wud (Oct 14, 2007)

Just to add from my personal frustration, check the saw blade verticalically to ensure it is square with the saw base too. If your blade is off vertically, you will experience gaps front to back if the blade is off vertically. 

I also recommend using as thick of a blade as you can find. This helps reduce blade wobble. 

For 45 angles, I recommend you purchase a precision square. I have a couple I purchased from Woodcraft for less than $20 each. Cut some scrape at 45s and tape together...fit your precision square on the outside and inside of your joint.....if there's no light between the wood and square, you should be pretty close to a properly aligned saw. 

I will say the time to align you saw pays back 10 fold from future frustration and waste of wood. Most of the things I make require miter joints so it's nice when you get to a point when you can cut with confidence your pieces will fit together with no gaps. Good luck.


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