[amish_rabbi]

ordered the pro tram system, and I'm curious which way you guys tram your mills. I have just seen both lately

[SCzEngrgGroup]

I have no idea how you would even go about "shimming" the table. Where you shim/scrap/lap/whatever is a function of what error you're attempting to correct. You must fix the problem where the problem actually is. If the table has an error, you can't fix it by shimming the column, and vice-versa.

Regards,
Ray L.

[tmarks11]

Put a DTI (or that "pro tram" thing, although I haven't seen a "pro" use one yet....) in a noga holder in your spindle, and sweep the table.

How much error do you get with a 6" circle? Front to back and right to left?

The right to left error could be the adjustable collar on your mill head. You can adjust it by loosing it slightly, tapping the head on top with a rubber mallet to get a bit of shift. You can do that while the DTI is in contact with the table so you can precisely control how much head movement you are applying (similar principle to truing a vise).

Now that you THINK you have the left and right problem solved, you need to check if your column is perpendicular to the table. I wouldn't even think of messing with my column until I checked it with a square; you can cause more problems than you are trying to cure. Search "Cylindrical Square" on cnczone and you will find some nice pictorials of the process, although maybe requiring adaption to your machine. Like this one (ignore the picture where he shows using a combination square to check his table; BAD IDEA!)

http://www.cnczone.com/forums/charte...172-posts.html

Here is nyccnc youtube video on shimming the base of his Tormach to correct a slight tram problem:

https://www.youtube.com/watch?v=lle-k_ccFAA


That is one nice thing about a bridgeport; you can tram the whole thing in about 3-5 minutes at the start of every day.