Monday, January 2, 2017

How to Make a DIY Boring Bar

Difficulty Level (Easy, Medium, Hard, Insane):

I took a job boring some Acetal for a gentleman in town that has a bag pipe shop and the pieces that needed to be bored were fairly deep so I needed a rigid boring bar that would fit in the hole but be sturdy enough not to flex so I decided I was going to make one from scratch.

In retrospect, I should have done a bit more research as to the geometry of the boring bar and I would have designed it differently, but for now it'll do. I just might make some modifications down the road if for some reason it won't fulfill its purpose.

Marking the cut-out for the insert

Marking the center line

The AutoCAD drawing calculating the angle and clearances
Milling a flat at the top

Drilling the hole for the screw that holds the insert

Another view

Another view

Milling the flats for the tool holder

Another view
Drilling the screw hole to the final size before tapping
The installed insert

Another view

Another view

Close-up of the finished boring bar

Milling some shims to size

Another view


Metal lathe & accessories
Metal band saw

8" of 1" cold rolled steel
1 screw


4 hrs


It works but it will need some more tweaking


FrankS said...

I like it none the less. It does look however that the leading edge of the insert may be slightly off of 90° but that may be an optical illusion if you are satisfied with the rake angle and it produces chips why worry

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