I might get those 5mm cutters, or maybe go for a pack with some different sizes.

You read my mind with the 43mm mount - I was just looking at how easily it would fit.

Lots of photos...

Gantry with Z mounted:
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Z ballscrew bearing mount:
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Bits left to fit + old Z and 4th axis:
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Top of Z axis with stepper, 42:22 pulley:
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Ballnut, can just about see the mount:
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Router bits from Aldi, very cheap:
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Another view of Z axis:
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Finally the whole router:
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