Tramming my mill... simple question.

Pcmaker

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I have a PM25MV mill and I'm trying to tram it using one of these. Tramming the X axis was pretty easy. I'm now within .001, but the problem is the Y axis. I'm off by .025.

There's 4 allen head bolts holding the column. I've done this before and I have to shim the front or back with feeler gauges until I get to within 1 thou.

My question is, will this mess up the "squareness" of the millhead to the table? I don't think it will because the table moves side to side, front to back, and not the column.

If I unscrew the 4 allen bolts, the colum is guaranteed to shift side to side, even if a tiny bit, which will ruin the squareness of the column to the base of the milling machine. Instead of the column facing directly to the front, it will be shifted sideways a bit.

57-052-060.jpg
 
Won't make a bit of difference.
 
Another quick question:

I tram my mill by lowering the quill on the Z axis and I try to get both needles on the indicators to move at the same time. is this correct? If it's off, I tap the side of the head with a rubber hammer and do so until I can get both indicator needles to move as close to each other as possible
 
Never having used a device like that to tram, i cannot say. But if i had to guess, i would say that you are correct again. looks like they should read the same.
 
Getting the needles to move at the same time is not exactly correct. What you want bring the Z down until both indicators are loaded, then lock the quill or Z. You should first calibrate the tramming tool. Then adjust the head so that both indicators read the same.
 
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I had one of those I could not get repeatable readings with it the Chinese indicators were junk I sent it back.
I got a couple descent indicators and made my own . You do need to calibrate them
 
Another quick question:

I tram my mill by lowering the quill on the Z axis and I try to get both needles on the indicators to move at the same time. is this correct? If it's off, I tap the side of the head with a rubber hammer and do so until I can get both indicator needles to move as close to each other as possible
Why don't you just follow the instructions that came with the tool?
http://store-1wa94vq6.mybigcommerce.com/product_images/product_manual/pro_tram/pro_tram_manual.html

Tom
 
My question would be , why does anyone need 2 indicators and fancy tool to tram a mill ? What ever happened to using 1 indicator in an adjustable bar ? Am I missing something ? That thing looks like it turns a simple task into a nightmare . JMO :dunno:
 
Its mostly a marketing ploy. the (2) indicators will never be in the same plane, and will introduce some error.
 
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