Thread: Mitre Cut Distress!

Damienol,
Clamp your work. You will not hold it firm enough with your hands
When you are cutting at an angle the blade will push or pull you workpiece as it cuts and screw up your angle.

Ian

Green timber? I don't know if treating the timber dries it.
Timber not square and flat?

Mitre joints are tricky and your timber can be the problem if it is bowed or warps after joining.

Mind you, a cubby doesn't need perfect joints!

For the 'near to perfect as you can get...'. I set my saw to what I think is 45 degrees and cut using some scraps and assess how things are. If the cut is grossly out, ten I adjust accordingly but if it's within a bee's willy, then I use shims between the work and the saw fence. This is in place of any micro-adjusting of the saw. I use the shims from my dado set (.2mm etc) however things like playing cards can be used.

Originally Posted by Ian Smith

Damienol,
Clamp your work. You will not hold it firm enough with your hands
When you are cutting at an angle the blade will push or pull you workpiece as it cuts and screw up your angle.

Ian

Totally agree with the above.

However, there is one other area of concern when doing mitres especially if doing a picture frame or even doing the surrounds for a door - the pieces you are trying to match up at the mitre need to be the same length - this is essential when doing square frames - in rectangular frames then the 2 lengths and 2 breadths must be of identical dimensions.

As a suggestion, go to Officeworks, a drafting/Art supplier or similar and purchase some large set squares - they are not expensive but give you a large area of reference, come in a set of 2 ie 45˚/90˚ and 60˚/30˚/90˚. These should also allow you to easily check your setup on the saws as they are of a size which will highlight any errors.

Hope it helps.

As has been said to get the best result you need to clamp your timber,if you are on the table saw with any length over 500mm and say 45X90 or so you will struggle to get a acurate angle, the dropsaw should get you there,and has been mentioned any bow in the length will put it out.
As for cutting angles for picuture frames or such, Triton has a method which uses their cross cutting guide which is a 90 degree unit,they say that this 90 may be out a bit but if you cut one angle on one face and the other angle on the other face that will make a true 90,mark the matching pieces so you assemble correctly and make sure each side are the same.
I did this on my Triton for years with good results,when I got a contractors saw I bought the same gadjet from Rockler (could not use the Triton one as the table slot is not the same)
I hope I have explained clearly enough.

Hi nrb, do you mean a dual faced mitre gauge? I don't have one but CarbaTec used to sell these but I haven't seen them for a while - did a quick search and found it mentioned on the link.

SYDNEY TOOLS - Carba-Tec Dual Faced Mitre Gauge

Bob,that would do just don't change the setting once you have set it to 45.Add a longer fence to each side for more support.
The one I have came from Rockler in the US,I don't have the web address handy but if you Googled I'm sure you would find it then you could see exactly what I have
Good luck

There is a thread on this subject here, with pics of the jig that nrb is talking about in the last post. A pic is worth a 1000 words. The trick is to make sure the two fences are at right angles - they don't have to be at 45 deg to the sawblade.

Also, with what you are doing, as well as clamping the work, check the angle of the blade to make sure it is at 90 deg to the base.

For large timber like you are using, a mitre drop saw, accurately set, is the way to go, provided the blade teeth are sharp, and you drop the saw down on the work, rather than cross cutting in a slicing action with an SCMS.

45 Degree Gauge 003.jpg45 Degree Gauge 001.jpg45 Degree Gauge 002.jpgI have a Pic here

Originally Posted by Damienol

using 90x45 treated pine

There's your problem - you are not going to get furniture grade joins out of structural/landscape grade timber. As it dries out and shrinks, the mitre opens up, and when it gets wet and swells the mitre closes up and starts pushing the two halves of the join apart.