Cutting a perfect triangle on the TS

[Pat Barry]

I was referring to the legs of the triangular insert. For the sled to cut perfect miters, that triangle needs to isoceles.

you need to mount the 90 fence exactly 45 degrees and precisely with the 90 apex at the centerline of the saw blade kerf. To do this you need a bit of adjustability to the 90 degree fence. That is what the system you have pictured allows. You can loosen the knobs skew the fence and lock it down when it is spot on.

[Martin Wasner]

Make another sled with a crotch to put 90º corner into. I've got one for making corner blocks. I just used a miter box to make the crotch in a scrap of melamine. It rides against the fence and I hang onto the triangle I'm cutting, pushing both through the saw.

[Bill Space]

I am having trouble understanding why some information (link, name or whatever) that would allow me to view that video, which apparently others on the forum have viewed, is not included in this thread.

I would enjoy viewing it, if for no other reason I would understand what others are referring to.

I suppose it is fair to assume that since the member PMed the link to the video to the OP, that he does not want it viewed by the rest of us... Not sure why though...

Bit confused here, but without question do respect the wishes of the video's producer...

[Steve Demuth]

I am also a hand tool user and all I can say is, other than hit or miss/by luck, there is no way a handplaned approach could match that youtube method (verified by a digital caliper).

Is there a reason no one is posting the video link? Kinda an odd discussion we're having, with the actual method not yet in evidence.

[scott kinninger]

https://youtu.be/AgVthkUE4AU

[Steve Demuth]

0.01" variance is a lot when compared to the video the OP refers to. I watched that video a while back and my memory might be wrong and I think that video woodworker was talking about 0.001" tolerance or something like that.

I am also a hand tool user and all I can say is, other than hit or miss/by luck, there is no way a handplaned approach could match that youtube method (verified by a digital caliper).

If we are talking good enough mitres, the suggestions we see in this thread are good enough. But, if I understand the OP's requirements correctly, none of them will meet his needs.

Simon

So, having seen the video now, it's a clever, although terribly involved way of getting two legs of an isosceles right triangle identical. But note that in his demo, he would get close to .001" agreement on this test piece if he was off by the .01" I suggested would be good enough in creating his jig. I could duplicate (with respect to the jig) what he did with a good ruler and a hand plane quite easily.

At any rate, if the OP builds the sled he showed (which was taken from a youtube video as well), then his accuracy in his actual miter joints is going to be determined as much by how accurately he seats the insert dead center in the blade, and carefully against the fence (to create actual isosceles triangle) as it will .001" accuracy in construction.

[Simon MacGowen]

So, having seen the video now, it's a clever, although terribly involved way of getting two legs of an isosceles right triangle identical. But note that in his demo, he would get close to .001" agreement on this test piece if he was off by the .01" I suggested would be good enough in creating his jig. I could duplicate (with respect to the jig) what he did with a good ruler and a hand plane quite easily.

At any rate, if the OP builds the sled he showed (which was taken from a youtube video as well), then his accuracy in his actual miter joints is going to be determined as much by how accurately he seats the insert dead center in the blade, and carefully against the fence (to create actual isosceles triangle) as it will .001" accuracy in construction.

Was that the one the OP referring to? This is the first time I watched it. The OP can confirm if he was talking about the same video.

The one I watched -- clever than Ng's, I would say -- was a different one. I will see if I can find that one again.

Simon

[john bateman]

It seems to me you could just tweak the hold downs until you get your perfect miters, then glue a shim to the end of the leg that is short, so that it always contacts the fence equidistant.

[Sam Murdoch]

Thanks for all the tips. A member sent me a video that shows a great technique for doing this to a high level of precision. It is a very interesting method. I'm not sure if it's proper to post the name of the video here, but I can pm it to anyone interested.

Don't know why it would be a secret that can't be posted in the thread - but will be happy to get a PM with that video link. Thanks.

[Brian Behrens]

I wanted to make sure it wasn't against the rules or that people thought I was promoting the video . I guess it's ok. Just search YouTube for Kings Fine Woodworking extreme crosscut sled . The triangle method is towards the end of the video

[Simon MacGowen]

I wanted to make sure it wasn't against the rules or that people thought I was promoting the video . I guess it's ok. Just search YouTube for Kings Fine Woodworking extreme crosscut sled . The triangle method is towards the end of the video

That is exactly the one I watched. I liked the way he taped the blocks to set up the cut. As long as you can the perfect squares (much easier than a perfect triangle), you can create a perfect triangle using his approach.

Thanx for the search key.

Simon

[Brian Behrens]

This is the video that answered my question. Skip to around 32:30.
https://youtu.be/njsD5W6fcI0

[Charles Lent]

For very accurate angles I use my MiterSet jig to set my miter gauge to exactly the angle needed. Add a jig to the miter gauge to hold the piece being cut and make the cut.

Charley

[William Young]

I haven't seen the video mentioned above, but why not keep it simple with a little trial and error. Start with a plywood scrap with one straight edge. This will be your hypotenuse. Now set your miter gauge to 45* as accurately as you reasonably can. Set the plywood hypotenuse against the miter gauge fence and cut one short leg of the triangle. Now flip the plywood blank and cut the other short edge. The angle between the two cut legs should be nearly 90*. Check it with your square and, if necessary, adjust the miter gauge and make the cuts again (shave just a little off of each leg). Check and adjust until you get the angle to the precision you want. Now with the miter gauge precisely set, cut the final triangle from a fresh blank.