Ensuring a reference square is, well, square

[perry]

I've got a 19" Millright MegaV I've converted to Masso. I need to make a bunch of parts that will require milling both sides, and I'm thinking the easiest way for me to do this is to cut a big right angle square out of some scrap 3/4" aluminum, then semi-permanently attach that to my T-plate bed. Once that's square to the machine I can just use it as a reference for either a low profile vise or for clamping already cut pieces. I know I could just cut the part in place and leave it there, but I need for the square to be as far off to the side of the bed as possible, ideally partially underneath the Y rails, which is out of the reach of the spindle.

So, without having an edge probe, what's the best way for me to ensure that reference square is square to the machine? I'd like to get the tolerance as tight as possible, since some of the parts I'm making are interlocking. I need a little wiggle room (maybe 0.25mm on each side of each interlocking key). Are there any built-in tricks in the Masso controller for this?

Or is there a better way to approach this kind of problem? Visual examples are appreciated -- it's easier for me to imagine how I'd do it if I see someone else doing it.

Thanks!

 

[safeairone]

Perhaps I m misunderstanding what you re trying to do, but if you are just trying to line an object up with an axis of travel on your machine, it s a simple matter of putting a suitable indicator (test, dial, etc.) in the spindle and jogging the object past the indicator, adjusting your object till the needle on the indicator doesn t move, like they re doing in this Haas Tip of the Day video on squaring a vise (skip to 2:55 if you don t want to see the prep work):

If your object is beyond the reach of your spindle, you can always use a magnetic indicator base attached to a point on your machine that moves past your object when jogging, and adjust your object till the needle doesn t move as you re jogging past. (pic #1, crudely depicting a top-down view of a Bridgeport-type mill)...

...Or use a machinist s square against a known perpendicular reference on the machine (the edge of the table in pic #2)...

Or machine a piece of appropriately-wide stock so that it has 2 perfectly parallel opposite edges, indicate that stock on your machine, then butt your object against this piece of stock and clamp it down (pic #3).

 

[perry]

Thanks. those are good tips. What I'm trying to do is make sure that the reference block I lock down to the T-slot is perfectly square to the spindle, on both X and Y axes. I guess I'll need to get an indicator that works at an angle like that. I should be able to get one that slips under the Y axis frame slightly, and can be mounted in the collet.

What I need to do Is cut both sides of a part with precision, so I need to be able to flip the piece either in a vise or using the right angle block as a reference. Because of the design of the Mega V, there's not really a good point to put in a square to check it, so I guess the indicator method is my best bet for checking square.

Thanks!