Decking a block - OK to do?

[Bob S.]

Re: 2 vs 3 axis milling machines - please elaborate

Decking (if absolutely necessary) can be done without disturbing the pad at all, but it requires a 3-axis mill; most average machine shops only have 2-axis mills, and can't make a straight perpendicular-to-centerline cut short of the pad surface.

John -

Could you (or someone else familiar w/ milling machines) please elaborate on the difference between 2 and 3 axis milling machines, and why a 2 axis machine can't properly mill a block deck?

Does the number of axes refer to the number of directions the cutting head can be moved in? ....and therefore a 2 axis machine can not mill only part of the deck surface without milling the stamp pad as well?

Anyway, thanks to everyone for passing on all the great info.....I value it so I'll have a thorough understanding of block machining when talking to machine shops/rebuilders.

Regards,
Bob S.

[Michael W.]

Re: Decking a block - OK to do?

Now I’ll leave the floor for those who are truly experts to comment. Just my two cents from personal observation a long time ago.

Thank you for posting that info. Your experience matches mine.

My belief is that the ability to measure minor 'flaws' (that have been there since original manufacture) is now in the hands of every local machine shop
as is the tooling to 'correct' them.

A classic case of fixing something that is not broken. How did we ever renovate kitchens without multi-beam laser levels?

[John H.]

Re: 2 vs 3 axis milling machines - please elaborate

John -

Could you (or someone else familiar w/ milling machines) please elaborate on the difference between 2 and 3 axis milling machines, and why a 2 axis machine can't properly mill a block deck?

Does the number of axes refer to the number of directions the cutting head can be moved in? ....and therefore a 2 axis machine can not mill only part of the deck surface without milling the stamp pad as well? Regards,
Bob S.

Bob -

Garden-variety block mills have heads that only move in two axes - fore-aft parallel to the block centerline, and vertically (depth of cut); with the rotating cutting head (see photo above), this creates a circular cutting path. A third axis (that allows the cutting head to move perpendicular to the block centerline) allows the outer edge of the cutter path to stop short of the stamp pad and then describe a straight line perpendicular to the block centerline so the head mating surface on the block deck is flat, but the stamp pad is untouched (and its surface is now slightly above the adjacent new deck surface).