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PostPosted: Thu Dec 01, 2011 7:01 pm 
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http://www.youtube.com/watch?v=4Fikcxmnn8Q


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PostPosted: Thu Dec 01, 2011 7:58 pm 
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Interesting but, I don't see the point in making all that sawdust with that facing tool. Why not just profile the shape to begin with? Seems you could save a ton of time and a ton of bit life.

You could even make your vacuum fixture to hold the scrap so you don't have to worry about it.

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PostPosted: Fri Dec 02, 2011 5:37 pm 
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Which bit's the interesting part? I'm not heckling, I've just seen so many different ways to machine a body now that I'm not sure what's 'normal' out there now.

I think the facemill was used because there's no shear on the cutter, since that tab under the neck is levered out and might chip out with a spiral cutter. You do get a nicer finish on contours with a larger radius cutter.

The finishing pass is a bottom to top scallop toolpath. It uses constant stepover on the surface rather than an axis, so the scallops are (theoretically) even over the whole surface. It's one of my favourites, but any little jitters in motion show up in the finish so it can cause some heartache if the path isn't proven.

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PostPosted: Fri Dec 02, 2011 7:49 pm 
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You could even make your vacuum fixture to hold the scrap so you don't have to worry about it.


I think he did.

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PostPosted: Sat Dec 03, 2011 7:56 am 
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Chris Pile wrote:
I think he did.


I re-watched and you're right.

I don't get what Bob means by "there's no shear in the cutter with a facemill". In which direction? Can you elaborate?

p.s., the most interesting question in my opinion is "where are the chips going?"

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PostPosted: Sat Dec 03, 2011 11:43 am 
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What I found interesting was the use of the face mill which I assume is to clear a large space so that there's no chance of recutting chips on the finish pass. The other thing that I found interesting was the vacuum fixture worked for both the top and back and I assume left and right-handed models. That's a pretty efficient use of fixtures compared to how we do it.


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PostPosted: Sat Dec 03, 2011 11:58 am 
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What I found interesting was the use of the face mill which I assume is to clear a large space so that there's no chance of recutting chips on the finish pass.


As a tool and die maker, I was trained to never assume a surface was level - and to make a skim pass to make sure it was clean.

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PostPosted: Sat Dec 03, 2011 12:47 pm 
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That makes sense if your face mill leaves a better finish than a thickness sander. I'm not sure mine does.

What i thought was interesting was using a face mill to rough profile.


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PostPosted: Sat Dec 03, 2011 7:05 pm 
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I had thought of using the Safety Planer this way and asked about it in another forum and everyone discouraged it. They said it wasn't designed to spin at the speeds that a router runs at. I wonder what speed he is running it at.


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PostPosted: Sat Dec 03, 2011 9:47 pm 
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That advice was right. The body of a Safety Planer is cast aluminum, the body of a face mill is made out of pretty tough steel.


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PostPosted: Mon Dec 05, 2011 10:25 am 
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So that's not a safety planer in the video? What's a face planer?


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PostPosted: Mon Dec 05, 2011 11:30 am 
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So that's not a safety planer in the video? What's a face planer?


It's a face mill....

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PostPosted: Mon Dec 05, 2011 6:33 pm 
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Andy Birko wrote:
Chris Pile wrote:
I think he did.


I re-watched and you're right.

I don't get what Bob means by "there's no shear in the cutter with a facemill". In which direction? Can you elaborate?

p.s., the most interesting question in my opinion is "where are the chips going?"


A face mill, in most cases, doesn't have any vertical shear so it won't tear out the top or bottom surface of a cut. It's not 'up cut' or 'down cut'.

I think the hand blowing the chips off with an air gun moves to quickly for us to see; the chips that fly into the background stay there for the whole video. I used to have my machine set up to blow off chips with an air blast (M code) every so often so we wouldn't need to clean off the vacuum fixtures between pieces.

Agreed with Chris on the level thing. I always face mill or joint any surface before it goes on a fixture for final machining. Wood rarely agrees to stay flat for long.

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