Tramming my mill/drill

[mikey]

I don't know Mikey. I doubt he uses a mill much at all. If you tram the head to your vise isn't that all you need? Your vise hold your work, no? I'm not arguing I just want to understand why the bed of the mill is more important than the vise.

I think its a matter of convenience. If you tram only the vise, then you also have to tram your rotary table or any part you bolt to the table and that gets tedious because you have to tram it in both X and Y. Easier to tram the head so it is square; then anything that sits on the table is theoretically square.

 

[ddickey]

Good point. So we can assume our rotary table and vise are flat? I'd like to believe my Kurt is, not sure about the rotary table though.

 

[mikey]

Assume nothing. Best to check and verify.

 

[AGCB97]

I just finished making one of those but I made the mistake of recessing the dial indicators into rectangle piece. Press fitting the rod into the center, meaning it is offset. Now when I rotate the opposite indicator is not on the same spot. Will probably have to make a new one.

I don't understand what you mean by "recessing the dial indicators into rectangle piece". This does not have to be built perfectly square to work because you zero the indicators on a common point before tramming.

I put the indicators in a pinch hole so they can be made to look relatively the same (lets say zero on top). Then each indicator is zeroed one at a time on a block at the front edge of the table (so you can see them w/o using a mirror). Recheck a couple times and it's now ready to use being perfectly square.

Even if you can't move the indicators in their holes, it only results in the faces not being symmetrical but it still works once each one is zeroed

Hope this helps and you don't throw away the time you spent so far.

 

[ddickey]

Like this. It works but is not proper as the opposite indicator never hits the spot you calibrated the first one after turning 180°. The indicators are offset from the axis of rotation.

 

[MozamPete]

When I tram the head of my mill I normally just put my largest end mill in (25mm dia.) and take light cuts on a scrap aluminum block, overlapping them slightly (i.e. almost the full width of the cutter between passes). If I cant feel a step where they overlap I consider it good enough and go on and do the other axis the same. No need for a indicator.
May not be the best method but I find it simple and I'm checking the result I'm actually after - that if I take multiple overlapping cut I will end up with a flat surface.