Road Bike -project, part III: How to reaming a bicycle head tube?

To make a bicycle head tube, you need a head tube reamer, a hacksaw, and a head tube blank. I have a Columbus Zona 36 mm head tube (CYRK18600) from which I will make the head tube. The head tube length is specified as 117 mm in the drawing, but it shortens during reaming, so it's advisable to make it 2 mm longer.
#framebuilding
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