Safe way for keyed miter

[ayuce]

Standard US way to cut keyed miters is to remove riving blade and blade guard of table saw then to use a jig to hold the box at 45 degree. As seen there :

http://www.howcast.com/videos/500376-Ho ... oodworking

I have small table saw but don't want to remove riving blade and blade guard for anything. Beside table saw, i've got hand held router and circular saw (with rail guide). I think i could devise a jig for one of them but no need to reinvent the wheel. Is there a proven and safer way to cut keyed miter joint to the boxes ?

 

[marcros]

Standard US way to cut keyed miters is to remove riving blade and blade guard of table saw then to use a jig to hold the box at 45 degree. As seen there :

http://www.howcast.com/videos/500376-Ho ... oodworking

I have small table saw but don't want to remove riving blade and blade guard for anything. Beside table saw, i've got hand held router and circular saw (with rail guide). I think i could devise a jig for one of them but no need to reinvent the wheel. Is there a proven and safer way to cut keyed miter joint to the boxes ?

The knife isn't necessary for such a cut, there is no danger of pinching. I would make a jig that guards the blade before, during and after the cut. That is if you have a blade that cuts flat or are willing to make one.

If you don't, I would make a jig and use the router. The easiest way of doing that is a form of router table with the jig running on top.

Depending on what keys you want to cut in- simple veneer ones could be cut by hand.

 

[SimonT]

To be fair it is a proven and fairly safe way to cut a spline joint, granted the blade guard is removed but i cant see there being a safer method with a circular saw? I may be wrong. You could always use a hand saw but would need a large kerf.
Not sure on the router version but unless you have a router table i can't see how there would be an accurate or safe way to do it with a hand held router either.

I may be wrong and others will probably have some very usefull suggestions too. Ha e you searched youtube for spline cutting methods / jigs? Im sure there would be loads of ideas.

 

[RogerP]

Putting safety issues aside just for the moment a router does give a much neater slot. The offset tips of the teeth of a saw can leave an untidy finish to the bottom of the slot.

 

[ayuce]

To be fair it is a proven and fairly safe way to cut a spline joint, granted the blade guard is removed but i cant see there being a safer method with a circular saw? I may be wrong. You could always use a hand saw but would need a large kerf.
Not sure on the router version but unless you have a router table i can't see how there would be an accurate or safe way to do it with a hand held router either.

I may be wrong and others will probably have some very usefull suggestions too. Ha e you searched youtube for spline cutting methods / jigs? Im sure there would be loads of ideas.

I've searched but all i found is basically same idea, exposed table saw blade with a 45 deg. holding jig. As SimonT said pinch is not a big risk but remove than reinstall riving blade, just cumbersome. Handheld circular saw on rails probably won't be as accurate as table saw. But blade won't be exposed. Jig could be upside down of table saw jig with a flat top for rails.

SimonT i'll think about integrated blade guard approach. should have plexiglass in the shop. Thanks.

 

[Steve Maskery]

That, in principle, is a ver good way of doing the job. The jig can't slip off the fence and she has replaceable sacrificial inserts so that she gets a zero-clearance cut. All that is good.
The two things that I would have issues with are the lack of guarding and the way she holds the workpiece.

I have two jigs for mitred splines. The Ultimate Tablesaw Tenon Jig can have any auxiliary fence attached to it, and I have one that holds a flat frame at 45 deg like that. It also has a clamp to keep the workpiece held firmly and of course it is guarded fore and aft.

For deeper workpieces like mitred boxes I have a jig like a cross-cut jig, but which holds the box at 45 deg. It has a tunnel guard built in to it so that I am not exposed to the blade in use.

Both jigs require the removal of the guard and the lowering of the RK, but for this operation that is not a risk. I just have to make sure that both get put back properly afterwards.

It works very well and I don't think that my safety is being compromised in any way whatsoever.

As to the neatness issue, it is true that a ATB blade is not suitable. Much better to get a Flat Top Grind and keep it just for this job. I got mine from Cutting Solutions. It's gon now but I will replace it when necessary. It gives a perfect cut, and finer than you would get with a router cutter.

S

 

[ayuce]

Really nice jigs there. Up to now i avoided modifying riving blade and blade guard, but it seems inevitable. There is no mid range serious hobbyist machines here. I've got a bosch pts10, practically a toy saw with sloppy fence but with a sliding table.

Riving knife holds the blade guard and higher than blade. Making a new shorter riving knife not a big issue, but will stay there always. A practical and safe blade guard not attached to riving knife and covers leaned blade? Let me search through the forum. Any idea appreciated.

 

[KevM]

If you're keen to do it with a handheld router you could try making (or buying!!!) one of these from Rockler.

Let us know how you get on!

 

[ayuce]

Thanks for the link ! Actually this is the way i'll try first. I'm gonna buid a jig for trim router, hope its power will be enough. Rockler's jig costs almost as much as my trim router. But first, i had to solve issues with landloard of my shop first :?

If you're keen to do it with a handheld router you could try making (or buying!!!) one of these from Rockler.
View attachment 2015
Let us know how you get on!

 

[marcros]

Thanks for the link ! Actually this is the way i'll try first. I'm gonna buid a jig for trim router, hope its power will be enough. Rockler's jig costs almost as much as my trim router. But first, i had to solve issues with landloard of my shop first :?

If you're keen to do it with a handheld router you could try making (or buying!!!) one of these from Rockler.
View attachment 2015
Let us know how you get on!

The Rocklet jig shouldnt be difficult to make- It is effectively a right angled piece, a table, and a couple of guides for the router.

 

[KevM]

Here's a link to a guy who's made his own from a few pieces of scrap ply, he uses a guide bush slot rather than a fence, but the same simple principle.

 

[ayuce]

A jig bookmark i've found on my computer. I ll check rockler's if it has anything to add this

http://www.woodsmithtips.com/2013/04/04 ... red-boxes/

 

[andersonec]

I don't understand the thinking behind the difference between a router cutter sitting up or down 20 mm and spinning ready to do damage and a circular saw blade poking up 20 mm covered by a jig.

If you make a jig with a long ply or mdf base with strips which runs in the slots of your table saw and a v shaped carrier for your box in the middle, you could build up the ply on the outside of the carrier so that it covered the blade, the only piece of blade then showing would be inside your v jig which is actually doing the cutting, when the jig runs past the blade the built up, tunnel section of ply would be covering the blade, it would also help stabilise the base of your sled / jig.

For a table saw jig you will definitely need a flat grind saw, I had a 16 tooth 8 inch dia saw reground by Atkinson Walker.

Andy

 

[rafezetter]

Here's a link to a guy who's made his own from a few pieces of scrap ply, he uses a guide bush slot rather than a fence, but the same simple principle.

That looks very simple and effective - will definitely try this.

 

[dickm]

Can't find it at the moment, but pretty sure Robert Wearing has a jig for doing this in either the Essential or the Resourceful Woodworker.
But either book is worth buying for the rest of their content. He was (actually, probably still is) a really clever guy.