Hi Guys,

As part of a discussion on another forum about line boring for miniature steam engine cylinders, I came up with this idea to enable a cutting bit on a boring bar to be adjusted accurately.

Boring Cutter Adjuster.png
Its basically a device that goes around the boring bar and pushes the tool bit forward. Using an M6 thread for the pusher will provide 40 thou or 1 mm per turn. Having index marks every 1.5 mm should make fractions of a thou relatively easy. As could adding a vernier scale.

Bugger, I've just spotted I've made an error in the knob calibration. It should be 39 not 49. Not to worry, it doesn't alter the way the device functions just the calibration.

I was calculating to get the index lines 1.5 mm apart to represent 1 thou ! That would make the knob diameter 19.01 mm, not 23.5 as I have shown. Or by making the index lines 2 mm apart would make the knob diameter of 25.46 mm.

The maximum boring bar diameter will be 20 mm down to about 6 mm.
Attached Images




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