I am looking to make some boring bars for my hollowing rig (articulated arm system). I am using 3/4”. Can someone tell me the approximate bend angle on the bent bars?
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Boring bars for hollowing
- Thread starter Kevin Courtney
- Start date
john lucas
AAW Forum Expert
just get online and look at a lot of the different tools. I made copies of the pictures and then blew them up on a copier and made my first bars. After that I had more experience and drew out my vessel shape, then took a coat hanger and bent it so that I could figure out what would reach into the shape i wanted to turn. then I just copied that on my 1/2" and 3/4" bars.
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It is more of a bend than an angle.
The critical part is the relationship of the cutter to the center line of the straight part of the tool before the bend. The straight part rests on the tool rest so it needs to be about 2/3 To 3/4 of the bar length.
The cutter should be in line with the center line.
If you plan to use a carbide you can put it right in line
With the center of the deepest cut.
In the diagram below I show the centerline at the midpoint on the usable part of the cutter. When it gets sharpened it gets shorter. A new cutter will be a bit left of center and a cutter near the end of its life will be right of center.
With an articulated system you can get away with cutting a little bit with the curve on the tool rest but you get more vibration. The cutter In line design is less vibration and it makes working with a laser or Camera easier since both the straight and curved tool will be in the same line.
The critical part is the relationship of the cutter to the center line of the straight part of the tool before the bend. The straight part rests on the tool rest so it needs to be about 2/3 To 3/4 of the bar length.
The cutter should be in line with the center line.
If you plan to use a carbide you can put it right in line
With the center of the deepest cut.
In the diagram below I show the centerline at the midpoint on the usable part of the cutter. When it gets sharpened it gets shorter. A new cutter will be a bit left of center and a cutter near the end of its life will be right of center.
With an articulated system you can get away with cutting a little bit with the curve on the tool rest but you get more vibration. The cutter In line design is less vibration and it makes working with a laser or Camera easier since both the straight and curved tool will be in the same line.
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