Critique my flycutting results

The angle of the dangle isn't angled enough lol . Ok it's just not cutting only on the tip it's rubbing ,, making the powder ,, if you grind the back of the angle off a bit it should be better. With a touch of coolant your finishes will get better.
 
chris.trotter said:
Thanks Bill - I am sure it is in some way inaccurate. Here's a very rough sketch of the basic idea:
View attachment 259334
- Arrow shows direction cutter is spinning

I don't have an angle gauge, so it's all just by eye right now. I will be trying something like this next: Fly cutter geometry

What do dusty chips mean?
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Your sketch looks right, but the tool looks like it’s upside down in the first picture. Maybe it’s just the pic (or my eyes).
 
Silverbullet said:
The angle of the dangle isn't angled enough lol . Ok it's just not cutting only on the tip it's rubbing ,, making the powder ,, if you grind the back of the angle off a bit it should be better. With a touch of coolant your finishes will get better.
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Coolant, good point! I had brushed on some Tap Magic, as it's all that was handy at the moment. Honestly, a lot of the geometry stuff is probably just wayyy off, and I need practice sharpening HSS.

MSD0 said:
Your sketch looks right, but the tool looks like it’s upside down in the first picture. Maybe it’s just the pic (or my eyes).
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The tool is upside down. :) Also it looks odd because you can't see the downward cant of the toolbit.
 
chris.trotter said:
Other input/suggestions?
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chris. When I'm grinding a bit for flycutting, I can never picture the shape and angle I need until I put it into the the flycutter and hold it facing down like it will be when machining. flycutter.jpgcorrect.jpgI took 2 of your pics and rotated them upside down and you can easily see that it is cutting at the lowest point (yellow circle and arrow) rather than the point you intended it to cut on (red). At the yellow points it would probably cut fine but, as others have already said there is no relief. not saying this is the perfect grind, but that will come with practice. Billh50 showed an excellent grind. Hope the upside down pics help. JR49
 
Thanks JR49! When actually mounted in the machine, the red part is the only part actually touching, but I suspect I haven't done enough relief, or really understand where the sharp edges need to be (thinking I probably dulled the bit rather than sharpening it when I ran over the diamond stone)
 
chris.trotter said:
... but I suspect I haven't done enough relief, or really understand where the sharp edges need to be.
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Take a good look at the tool that @Billh50 posted. It is basically a LH turning tool with a fairly large nose radius. The nose is where it cuts and the relief angles are under the cutting edges. Another option is to buy a brazed carbide LH turning tool and round the nose a bit and sharpen the carbide part. It works quite well and lasts a long time.
 
Are there LH and RH cutting flycutters?
 
Until I wire up a reverse switch, my machine only spins clockwise.

Based on what others have said, my cutting face is vertical, it needs to be angled back - plus I need some radiusing.
 
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