Mill tramming

[DavidR8]

I'm following a discussion in another forum where a person wants to ensure the the travel of the Z-axis on his RF-45 mill is parallel to the spindle.
Essentially he wants to verify that the Z-axis is travelling a parallel path as the spindle.
Recognizing my ignorance in the matter is this something that is a routine check?

 

[mmcmdl]

The spindle IS the Z axis .

 

[DavidR8]

Yup, I'm hip to that Dave
What he's suggesting is that the spindle could be perfectly trammed to the table but move diagonally if the head is not parallel to the spindle axis .
I can visualize what he's saying.
The blue line is the spindle centre line. The orange line is the exagerated path of the head up and down the ways.
My view is that things would have had to have gone seriously sideways at the factory (no pun intended) for the head spindle to be plumb while the dovetails got machines at an angle.

 

[mmcmdl]

Tram the table and then tram an angle plate mounted to the table . If it's not true , he has big issues .

 

[DavidR8]

Yup that's what I said...

 

[darkzero]

View attachment 361409

WTH! Where did you find that pic? Feels so weird seeing that part of the garage with so much room. I totally forgot the motor used to be white.

 

[vtcnc]

Yup, I'm hip to that Dave
What he's suggesting is that the spindle could be perfectly trammed to the table but move diagonally if the Z-axis is not parallel to the table.
I can visualize what he's saying.
The blue line is the spindle centre line. The orange line is the exagerated path of the head up and down the ways.
My view is that things would have had to have gone seriously sideways at the factory (no pun intended) for the head spindle to be plumb while the dovetails got machines at an angle.
View attachment 361409

Sorry Dave I’m confused. By definition the z-axis cannot be parallel to the table. Did you mean perpendicular? If so then yes, the tramming check would detect this and would cause problems as you illustrated.


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[jwmelvin]

I’ll just note that the problem need not be with the dovetails but with the joint between the column and the base. My understanding is that often requires shimming to bring it to 90°. Until recently I didn’t have an angle plate or cylindrical square, so I haven’t checked mine.

 

[DavidR8]

Sorry Dave I’m confused. By definition the z-axis cannot be parallel to the table. Did you mean perpendicular? If so then yes, the tramming check would detect this and would cause problems as you illustrated.


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My apologies
I should have said the head moving parallel to the spindle axis.
I corrected that post for clarity.


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[vtcnc]

I’ll just note that the problem need not be with the dovetails but with the joint between the column and the base. My understanding is that often requires shimming to bring it to 90°. Until recently I didn’t have an angle plate or cylindrical square, so I haven’t checked mine.

I agree any misalignment "should" be able to be addressed with tramming, aligning and shimming. Not much more complicated than that.

To discover that the dovetails were "out of square" would be a disaster to end them all. It is hard to imagine how that could happen considering even the most rudimentary setups, measurement checks, basic machine operations, etc. in the factory making those slides and tables - and then have it land at the customer site half a world away.