Tramming a mill head using angle plate

[Blueskys]

I use my mill head at different angles quite a lot.
So I was wondering; to get a reasonable 'back in tram' could
I use an angle plate on the table and and a dial indicator?
And then run my quill up and down. A couple thousands over
the 5" length of my quill should be all the accuracy I would need
for my normal jobs. Just wondering if there's a reason why this
doesn't work. Thanks.

[Lew Hartswick]

Sounds like it may work but WHY not use the table?????
...lew...

[Blueskys]

Sounds like it may work but WHY not use the table?????
...lew...

I guess reading up and down seems easier to me then reading round
and round. I turn the head quite often so if I can save a few minutes
that helps.

[rockrat]

If I have pictured this correctly, you would use one angle plate to verify one direction of the head?

I'm going to make a major edit here. Still sleepy and not thinking correctly.

I guess on further thought that this method is not bad by any means, just different than a norm. The only error that I can see being duplicated is any error in the angle of the plate being anything other than 90º, any clamping forces on the plate that might change it or something similar to that.

rock~

[Blueskys]

rockrat:
I see what you mean. I wasn't considering the interaction between
the two arcs of the head. Might be more trouble then it's worth
going back and forth between axises with the angle plate.

[rockrat]

See my post, I made an edit due to lack of following through on my thought logic. But is does seem like a bit of extra work moving everything around trying to capture the true alignment.

rock-I need more coffee-rat

[Black_Moons]

'around and around'? you don't tram the table with the spindle running, you manualy move the spindle with a wrench on the drawbar nut or something with a TDI mounted into the spindle, its very quick an easy.

[dp]

Here's how I do it:

http://www.youtube.com/watch?v=ZfioLDhBNBQ

[BobWarfield]

Using the angle plate or a cylindrical square is valuable, but is not necessarily the same function as tramming normally refers to.

If your head rotates, the angle block will not detect whether the spindle is parallel to the Z axis. It will simple tell if your Z ways are perpendicular to the surface the angle plate sits on (presumably your table).

It is useful, therefore to use the angle plate to shim the column, which is a less frequent thing to check (hopefully once unless you move the mill or have a real bad crash). Whereas tramming is something you could argue to do every morning when you start using the mill.

I have heard the angle plate operation referred to as "squaring" the mill, rather than tramming. Here is a shot of squaring my IH mill with a cylindrical square:



BTW, you need to check squareness to both X and Y, so 2 measurements are needed at right angles. In that case, I am checking "nod", which is squareness relative to Y. If I turn the DTI and cylindrical square 90 degrees, I measure "tilt" left or right of the column.

Cheers,

BW

[Forrest Addy]

The solution is simple for a vertcal miil: make a gizmo - actually a tool shank with a precision level vial mounted crossways in it. Naturally the machine has to be accurately leveled first. Then with a vial showing the reversal error of the spindle you can quickly bring the tilt (and nod if you have it) into tram limited by the accuracy of the machine's leveling. If you need specal accuracy to insure the squareness of bores with the reference face, you'd better finish with a quick tram of the machine table.

Here's a source for level vials:

http://geier-bluhm.com/products_tubular_01.html