91 x 4 drilled holes. Yes, counting.
by John
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.
The mill drill setup. Re- indicating the vices again took me about 45″.
Firstly all of the holes were center drilled, then drilled through. The rivet confirmed a nice sliding fit.
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”.
johnsmachines 
Incredible work. Are you selling these or are they for your personal collection?
Cheers
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Thankyou! Not for sale. Too many hours work.
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