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Reinis Kanders
10-24-2016, 2:02 PM
I like technology and all that, but this story was kind of funny.

http://www.popularwoodworking.com/woodworking-blogs/how-i-use-a-cnc-cutting-parts-using-a-cnc

I am also annoyed at my neighbors workers using one of those loud oscillating tools that supposedly make flush cuts easier. Those things are definitely slower than a chisel would be though. Each blade probably costs the same as a cheap chisel so at least they are helping the economy:)

glenn bradley
10-24-2016, 2:20 PM
This is good. Anyone who finds cutting out a triangle to be challenging should use a CNC.

Prashun Patel
10-24-2016, 2:27 PM
Good thing he doesn't need a triangular mortise with sharp corners.

Ryan Mooney
10-24-2016, 4:16 PM
I can't tell - is he keeping the triangle or wants the triangular opening? If you wanted a triangular opening it would be mildly challenging (although the CNC still leaves round corners), if its just cutting the triangle.. you guys have it covered.

Mike Henderson
10-24-2016, 6:02 PM
I don't see anything really exciting about this. As others have said, if what you want is the triangle, why cut it from the center of a board. Seems like a lot of waste that way. And it would be pretty easy to produce a triangle with a table saw, for example.

And if what you want is the triangle hole, the CNC can't cut sharp corners so you'd still have to do some hand work.

I know he was just trying to give an example, but it's a poor example.

Mike

Bill Houghton
10-24-2016, 6:12 PM
I think, from the text, he wants the opening. It does seem like overselling - lots of ways to make that opening.

Phillip Mitchell
10-24-2016, 9:40 PM
I don't know about that article, but I will say that despite it's unholy racket, an oscillator has saved my butt more times than I can count in certain situations (carpentry, remodeling.)

Karl Andersson
10-25-2016, 7:50 AM
Funny thing, when I opened the article there was a side window offering me a DVD "Using the Versatile Chisel With Jeff Miller"

I wonder how many "hobbyist" woodworkers are using a CNC router? I realize that my concept of quietly imitating Geppetto out in my shed, building anything from spoons to chests with hand tools is not what many would call fun, but just how much furniture does the family/friends need that a hobbyist needs to have machines intended for repetitive, high-capacity work? Or is the CNC used just for precision in that case? There are ones that carve, for people who can't take the time to learn (oh the humanity!), but I'm thinking more along the lines of this article - who is it for?

Rob Young
10-25-2016, 11:49 AM
I can't tell - is he keeping the triangle or wants the triangular opening? If you wanted a triangular opening it would be mildly challenging (although the CNC still leaves round corners), if its just cutting the triangle.. you guys have it covered.

Add another axis to the CNC so that the bit can be tilted and you can cut crisp, sharp, inside corners. Limitations based on size of hole, length of cutter, degrees of freedom in axis, etc.

Or just go knock it out with a saw and chisels.

Bill Houghton
10-25-2016, 12:19 PM
What he emphasizes in his post on CNC is the difficulty of smoothing the acute inside corner of the triangular opening (I take it this is a detail he uses on his furniture). But the picture he presents has the telltale curve of a machine operation, not the sharp angle possible with hand tools; so it seems like he's solved one problem, but created another. Or maybe he finds the curved inside corner fits within his designs.

Ryan Mooney
10-25-2016, 1:49 PM
Add another axis to the CNC so that the bit can be tilted and you can cut crisp, sharp, inside corners. Limitations based on size of hole, length of cutter, degrees of freedom in axis, etc.

I suppose yeah if you have a V bit with an angle less than (or equal to) the angle of the inside corner. Getting very deep on that sharp inside corner could be a bit of a trick to do without chatter though...

Rob Young
10-26-2016, 10:34 AM
I suppose yeah if you have a V bit with an angle less than (or equal to) the angle of the inside corner. Getting very deep on that sharp inside corner could be a bit of a trick to do without chatter though...

In metal work, inside corners can be made square by broaching. Not sure if this would work for wood or acute inside corner of triangle.

Art Mann
10-26-2016, 1:25 PM
I am one of those guys who saved up and bought a CNC router. I have been a woodworker for about 40 years and have cut this kind of opening many, many times for various projects. I can tell you with no hesitation the the CNC router is, by far, the easiest way I have ever used to make this sort of cut accurately. I have done this sort of thing on my CNC router very often. It is trivial to set up the cut. If you need really sharp corners, it is simple enough to use a coping saw, scroll saw or a rasp. If you want to do this work using hand tools, then that is your motivation to not use a CNC router but it is definitely not the fastest or most accurate way.

Bruce Page
10-26-2016, 2:12 PM
In metal work, inside corners can be made square by broaching. Not sure if this would work for wood or acute inside corner of triangle.
Rob, broaching wood works quite well as long as you use a backer board to prevent blowout. I broached these 3/8 square holes through 1" thick white oak using a metal working broach. I wish I could say I was talented enough to do it Neander style..

Bruce Page
10-26-2016, 2:22 PM
I am one of those guys who saved up and bought a CNC router. I have been a woodworker for about 40 years and have cut this kind of opening many, many times for various projects. I can tell you with no hesitation the the CNC router is, by far, the easiest way I have ever used to make this sort of cut accurately. I have done this sort of thing on my CNC router very often. It is trivial to set up the cut. If you need really sharp corners, it is simple enough to use a coping saw, scroll saw or a rasp. If you want to do this work using hand tools, then that is your motivation to not use a CNC router but it is definitely not the fastest or most accurate way.

Like Art, I also have a CNC router. I have never understood the disdain some woodworkers have for CNC. The CNC opens up a woodworker's options to design & create. When it's all said & done, it is just a tool.

Malcolm McLeod
10-26-2016, 2:36 PM
...it is just a tool.

If you unplug the power, pull all the servos off, and install 2ea. hand and 1ea. foot cranks (since its probably >2 axis), does that make it's results neander worthy? ...just wonderin'.;)