DIY Boring Bar

Here I go over the newest shop made tool I've added to my collection.  Enjoy!

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I recently had to clean up the inside of some fairly large diameter holes. The best way to accomplish this would be with a boring bar, but a boring bar I did not have...till now. 

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I used a small section of steel rod turned down to size and milled/cross drilled to accept a HSS cutter (broken drill bit). I shaped the cutter on the belt sander and didn't even bother moving to the oil stone before cutting. I needed this tool to true up the inside bore on a customers project.  Here you can see the before and after shots of this operation (rough hole was cut via cnc).  

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Adjusting the diameter is easier then I assumed it would be seeing as there is no "fine adjust". A few light taps to the back of the cutter with a loosened off set screw lets you bump to size easily. 

The hardest part of this whole project was indicating off the rough hole to find exact centre and switching out tools.  The actual cutting was easy as pie and left a beautiful surface finish!