Any ideas on a quick way to square up a workpiece on the mill table?

[ChazzC]

I use a number of methods to quickly align a workpiece on the table; some are usually close enough so they don't need further checking, others get me very close so the part can be tapped in as in @Karl_T 's post and as you would do to tram in your vise.

Quick & Dirty #1
I drop a pair of 12mm Dowel Pins in the T-Slots (12mm fit perfectly in my Mini-Mill),


and push the part up against them (this is what you would see from the back of the mill):



Quick & Dirty #2
I lay a long 31/64" Dowel Pin (or in this case a Drill Blank) in the T-Slot; on my Mini-Mill, 31/64" drops deep enough into the T-Slot to locate and can't be pushed out by the workpiece (again, view from behind):



Quick & Dirty #3
Machinist Square:



If you need to mill edges of the workpiece, you can use stand-offs (@Karl_T ) or 1-2-3 Blocks and push the part against the Dowel Pins, or push one the 1-2-3 Blocks against the pins and align the part with the edge of the 1-2-3 Block.


Another method is to use a Fixture/Tooling Plate which is aligned to the mill:

The three plates at the top were cut from a Sherline 13" x 7" plate, and have mini-T-Slots and reamed 0.250" holes that can be used for workpiece alignment (also 10-32 tapped holes for use with toe-clamps). The other plates have 1/4-20 tapped holes that are accurately located & uniformly countersunk on a CNC Mill, like the holes on this SMW (Saunders Machine Works) plate (mine is a 10" x 6", which is not currently available; I wanted to be able to use it without removing my vise):

I have a Hobby SMW Mod Vise mounted on the plate which gives another option for holding & aligning.

Saunders makes special 1/4-20 Fixture Pins that locate on the countersink of the 1/4-20 holes:

0.250" Dowel for Sherline (top) and SMW 1/4-20 Fixture Pin (bottom)

 

[mmcmdl]

Like Chazz #3 , I use a Starrett master square then indicate . Mount a bar to table to relocate multiple parts . Usually its a rotary table or indexer I mount . One of the Hardinge indexers was ground parallel so I could throw it in the vise for easy setups .

 

[ChazzC]

Like Chazz #3 , I use a Starrett master square then indicate . Mount a bar to table to relocate multiple parts . Usually its a rotary table or indexer I mount . One of the Hardinge indexers was ground parallel so I could throw it in the vise for easy setups .

I frequently hold the small fixture plates in the vise's outer jaws, and when I "fixed" my SpinDexer I machined the base square to the axis so I can clamp that in the vise, too.