Cutting Mitres
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beech1948
Established Member
I've been trying to find a picture of this but have failed so your stuck with my wordy explanation. I'll post a picture if I find one.
Objective: Create a mitre sled for a table saw such that two corner pieces are cut at the same time thus creating two pieces which meet to form a 90 degree corner.
Method:
1) The base is a piece of ply, say 15mm thick and about 3 ft square. Could be only 2ft square if you want. Your decision.
2) Top is furthest away from you.
3) On the top mount a piece of wood across the width 3ft wide by 4 inches tall. Repeat on the bottom.
4) Draw a line down the middle and over the top and bottom
5) Mount two pieces of 2x2 or what have you at 90 degrees to each other such that they form a 45 degree shape against the centre line. That is a ^ shape. On mine I offset one side to be 4 inches lower down the base.
6) Carefully fasten to the board and try to get as close to 45 degree as possible. I use a 45 degree plastic tech drawing transparent triangle. The pointed top of these would be about 6 inches from the top of the base.
7) Mark the base with the mitre square slots position. Remove base, attached mitre square runners, remount, check for squareness
8) Check and Align the base and the centre line with the table saw base and cut a saw kerf throught the top piece and some 18 inches into the base but not all the way to the bottom.
9) Place two pieces to be mitred onto the base so they form a 90 degree corner, in my case offset by 4 inches for one piece.
10) Run both pieces through the blade.
You will be left with two pieces which must make up a 90 degree mitred corner even if they are 46 and 44 degrees. If you get it right though you will have two matching 45 degree mitres.
Works every time.
Once it works then screw a piece of transparent plastic over the blade running line as a safety guard..
Al
Objective: Create a mitre sled for a table saw such that two corner pieces are cut at the same time thus creating two pieces which meet to form a 90 degree corner.
Method:
1) The base is a piece of ply, say 15mm thick and about 3 ft square. Could be only 2ft square if you want. Your decision.
2) Top is furthest away from you.
3) On the top mount a piece of wood across the width 3ft wide by 4 inches tall. Repeat on the bottom.
4) Draw a line down the middle and over the top and bottom
5) Mount two pieces of 2x2 or what have you at 90 degrees to each other such that they form a 45 degree shape against the centre line. That is a ^ shape. On mine I offset one side to be 4 inches lower down the base.
6) Carefully fasten to the board and try to get as close to 45 degree as possible. I use a 45 degree plastic tech drawing transparent triangle. The pointed top of these would be about 6 inches from the top of the base.
7) Mark the base with the mitre square slots position. Remove base, attached mitre square runners, remount, check for squareness
8) Check and Align the base and the centre line with the table saw base and cut a saw kerf throught the top piece and some 18 inches into the base but not all the way to the bottom.
9) Place two pieces to be mitred onto the base so they form a 90 degree corner, in my case offset by 4 inches for one piece.
10) Run both pieces through the blade.
You will be left with two pieces which must make up a 90 degree mitred corner even if they are 46 and 44 degrees. If you get it right though you will have two matching 45 degree mitres.
Works every time.
Once it works then screw a piece of transparent plastic over the blade running line as a safety guard..
Al
Trouble there Al is that our friend wants to make boxes, even with a 10 inch TS the max depth of cut will be less than 2 inches, for box sides deeper than that you have to lay the timber flat and cant the blade.
Roy.
Roy.
RogerP
Established Member
Digit":1ofg7rpd said:
Quite agree and I don't use it but the method was mentioned so I found an appropriate page.
I cut my mitres on a bandsaw then use this shooting board - which as you can see is ideal for boxes. The finished mitre is as perfect as one would hope for and does not take very long.
I agree that they work well Rog, but the reason I changed over to cutting on a TS was the availablity of good quality cross cut blades plus the ability to use stops on a TS jig to ensure accurate lengths as well.
Getting angles, plus lengths correct is what makes mitres such a challenge.
The last box I made I French polished and even a minute inaccuracy at the corners is obvious.
Roy.
Getting angles, plus lengths correct is what makes mitres such a challenge.
The last box I made I French polished and even a minute inaccuracy at the corners is obvious.
Roy.
beech1948
Established Member
Digit,
Just reread the thread and your right. Lost sight of the end product there. Sorry.
I would revert to a tried and trusted method.
Rough cut to 45 degrees
Use a mitre shooting board to refine to 45 degrees.
Al
Just reread the thread and your right. Lost sight of the end product there. Sorry.
I would revert to a tried and trusted method.
Rough cut to 45 degrees
Use a mitre shooting board to refine to 45 degrees.
Al
beech1948
Established Member
Digit,
I thought we were talking about boxes.
Hardwood thickish and long does not easily compute into a box. Your typical box might only be 3/8th sides and probably not more than 8 inches high.
Even a large box is not that much of an issue surely. Say max of 1 inch thick by 30 inch sides. A sharp blade, a bowl of porridge and a smile and its done in no time.
Unless you really mean lazy... :roll:
Al
I thought we were talking about boxes.
Hardwood thickish and long does not easily compute into a box. Your typical box might only be 3/8th sides and probably not more than 8 inches high.
Even a large box is not that much of an issue surely. Say max of 1 inch thick by 30 inch sides. A sharp blade, a bowl of porridge and a smile and its done in no time.
Unless you really mean lazy... :roll:
Al
I do, I do! :lol:
But also I can cut the angles and guarantee the length all in one go on my TS jig whilst you are spending time checking lengths and attempting to get two pairs the same length.
The way I make boxes, clock cases etc is as follows.
Prepare the blank sides, leave the height/width over size, set the stops to required cutting length, cut one end at 45.
Mark cut end A. Cut matching joint on tother side of blade and mark as A, repeat for C and D.
Reset stops and cut opposite ends.
I now have 4 pieces of timer mitred on both ends of guaranteed size and fit. Make tea!
I now reduce height/width to remove any break out and glue up two corners on home brewed box jig, when dry repeat with other corner. I now have to 'L' shaped pieces that I can glue up knowing that they will fit.
Next make and fit top and base.
When dry I separate top from base by cutting on my trusty TS.
The sawn edges are then leveled, another nasty job with a plane I find, on my again home brewed, overhead router.
No chance of propellers or lids that will fit only one way.
Meanwhile, back at the shooting board.... :lol:
Roy.
thecoder
Established Member
Thanks for all the feedback and suggestions guys really appreciate it....
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