91 x 4 drilled holes. Yes, counting.

Today I drilled the girders of the chassis under the Armstrong cannon.  Each girder has 91 rivet holes.  Later I will need to drill more for the gear shafts, and for the center pivot bar.

The holes are 2mm diameter.

PANA3767

The mill drill setup. Re- indicating the vices again took me about 45″.

PANA3769

Firstly all of the holes were center drilled, then drilled through.  The rivet confirmed a nice sliding fit.

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364 holes, through 5mm of steel done with one center drill, and one 2mm drill.  That is pretty impressive IMO.  More than 1.8 meters of steel with 2 drill bits.  And using my olive oil and kerosene lubricant-coolant.   And the bits still seem to be sharp.

Each girder took about 28″ to drill the 91 holes.   CNC of course.  It has been a while since I said it….. “I love CNC”.