Hi all,

This is a what I assume to be a very basic question, yet it's been one I have been meaning to ask every time I need to bore a longish hole.

It seems that whenever I need to bore a long but relatively skinny hole, I have issues with the swarf eventually clogging up and fouling the boring bar cutter. This, at best affects the surface finish because the swarf ends up getting between the workpiece and the cutter and at worst can damage the boring bar.

My latest project being to make a quill handle for my mill. The body will be made from 50mm BMS and the hole needs to be a neat sliding fit on a 25mm shaft. I'm opting to make an adjustable handle such that the main handle will be spring loaded and pulling it in towards the machine will dis-engage the locking pin, allowing 360 degree adjustment to a comfortable angle. Releasing the handle outwards allows the pin to re-locate to the nearest hole.

So, the main body being 50mm BMS and centre bored to 25.05mm and approx. 60mm long has once again presented issues where the swarf eventually gets clogged and fouls the cutter, degrading the internal finish.

It obviously gets better as the hole gets bigger as it allows the swarf a larger volume to eject. But at smaller diameters, what is the best practise?

Do I need to hold a compressed air gun down the guts? Gotta be a better way surely?

Any advice much appreciated.

Simon


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