Precision Matthews PM-728VT CNC conversion

@jwmelvin: Why don’t you like your trays?

I wanted them sloped towards the left (the drain) but the front one is not sloped enough. Now they are both spot welded in, so I cannot easily tilt it further. The second reason is that the dual drain system (needed because of the transverse support for the mill breaks the space up in two) seems overcomplicated.

Am tempted to yank out both trays and replace them with one 24x24" tray placed just below the top frame (ie. just below the crossmember that supports the front of the mill). Will see for now how this setup works.

Next phase will add the belows instead of the pathetic rubber sheet that PM delivers it with.
 
I went a different way with my table. It is wider than the maximum X travel of the table. This way, there is zero chance of anything accidently bumping the table in operation. The wide stance will prevent rocking. The Mill is mounted on 3/8th steel plate, which is welded to the 2 inch square tubing with 1/8th wall. They Y axis dimension is also generous, to ensure lots of move for oversized items with overhang in that axis as well. As a note, I did not go CNC, nor will I.

It is an 8 legged table with 8 adjustable feet for precise levelling. Four of the legs are directly under the mill to reduce the chance of tube flex from occurring. Flat panels could be added to the sides if any flexing is evidenced.

That looks great and promises to be stable. I am very constrained by space, and cannot afford a structure like that. My base's Y-axis is long enough to protect the motor in the front. I have built an enclosure that will partially protect the x-axis from bumps. Long material will stick out through the sides where I plan to place a curtain rather than a solid wall on the lower half.
 
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Two bellows to cover the ways.


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Have run the system but the trays are leaking coolant. So have bought a granite countertop remnant from a local yard and will mount the mill onto it.

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Our plumber came by to do some other job do i asked him to put a drain hole.

Can anyone suggest a spindle/router bit that can be used on granite? I am thinking of putting the slab on the CNC and finishing a countersink and maybe add some drainage grooves.


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Any examples of endmills for granite? Amazon search is mostly showing conventional cutters


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Good sized barrel cactus you have there- I have a couple nice ones myself but not quite that large
-M
 
Any examples of endmills for granite? Amazon search is mostly showing conventional cutters


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I will add that I did try milling a slot with a small carbide endmill in granite a few years back. Got about an inch before there was a smooth nub where the endmill used to be. In all fairness, it did mill a slot at first. I'd stick to abrasive methods. Perhaps a diamond mounted point would work well if kept cool.

 
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