Quote Originally Posted by remidgett View Post
Did you purchase the pallet blank as raw 1/2" stock & machine it flat yourself (fly cutter or face mill?), or was it flat enough as acquired, or possibly purchased it as a machined flat piece?
I've seen other, similar tooling plates that had the tapped holes in a diamond pattern rather than square; wondering if there may be a significant advantage to one over the other.
The general standard for aluminum tooling plate is named that. In use, most call it a sub-plate. Typically, these are sacrificial, drilled and milled into, not supported by parallels, sometimes to gain room below spindle when a vise is too high. Can't recall a certain alloy grade, but it machines like cast aluminum, of which #356 is common. Aluminum has a finish similar to cold rolled steel, being lighter weight not difficult to check flatness, but parallelism is more important. Flycutting the absolute minimum will reveal and correct that reasonably well, within restraints of ''Y'' axis, that ''X'' will not be so reliable. No machine with table overhang on saddle (Abbe' error) can.
Another limitation occurs by extending ''Z'' from spindle housing. If quill housing to table perpendicularity cannot be trammed, I wouldn't mill the plate.

There is no conventional matrix pattern to distribute tapped holes, aside from sufficiently accurate alignment to travel, IF adding dowel holes to register parts. After all, real benefit of palletizing isn't to simplify clamping, it's to register parts on a common datum, not particularly identical parts.
All holes create a problem when they collect chips, so a well-perforated plate while looking real downtown big time, and source of irritation. Plug tapped holes with short slotted headless screws, dowel spots with barely loose, minimally chamfered (face off & break edges) cold-rolled steel rods, extract those with a magnet.

If I were to fabricate pallets, they'd be raw tooling plate, toe clamped (or counter-bored for cap screws) to table slots at each end.
Drill & chamfer both sides, tapped through for a coarse thread, dowel spots blind.
The pattern would be offset 1/2 distance of adjacent row along ''X'' but less in ''Y'' axis. o o o o o o o o
o o o o o o o

The spacing deter mined by length of toe clamps to be used, not full size 1/2" clamping, more like 3/8" even 1/4" I'd make from flat steel bar, above C1018 grade, that mills so poorly.