Pm932 Pdf Time To Redo Tramming

richz

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I was trying to make some machinist clamps and came up with this. I believe due to moving the headstock down to mill the recess after removing the drill bit and chuck indicates that that I need to start back at the beginning of getting my mill set up properly. When I first got the mill I was in a hurry to get it set up and was very new to machine setup. I believe that the order of getting it right should be to start with adjusting the gibs, then getting the head square to the column and last getting the column square to the table. So a bunch of questions. I am going to adjust the gibs so I feel a slight drag when turning the hand wheels. Next align the head to the column, first on the X axis which I understand how to do, on the Y axis I am unsure so I will need some help there. Last would be the column to the table which I understand how to do. Is this the right order?

IMG_0671.JPG
 
It all starts with the reference surface, which should be stated in the manual. I know my way around knee mills, but not sure on bench top mills where the reference surface is. Read the manual, and probably someone else will respond here as well...
 
I was trying to make some machinist clamps and came up with this. I believe due to moving the headstock down to mill the recess after removing the drill bit and chuck indicates that that I need to start back at the beginning of getting my mill set up properly. When I first got the mill I was in a hurry to get it set up and was very new to machine setup. I believe that the order of getting it right should be to start with adjusting the gibs, then getting the head square to the column and last getting the column square to the table. So a bunch of questions. I am going to adjust the gibs so I feel a slight drag when turning the hand wheels. Next align the head to the column, first on the X axis which I understand how to do, on the Y axis I am unsure so I will need some help there. Last would be the column to the table which I understand how to do. Is this the right order?

That's how I did mine. I adjusted the Z axis gib until I could just slip a .002" feeler gauge between the top of the gib and the dovetail. Then I checked the head to column "nod" using Rollie's Dad's method. I stuck a 8" long piece of 1/2" precision ground rod in a collet and checked runout next to the collet and 8" away. Averaged the two runout readings and my "nod" was almost zero. Can't remember the exact number but it was certainly less that .002" which I thought was good. Then I trammed the column to the table in the Y axis by shimming. Once that was done I trammed the head to the table in the X axis. Not professing that this is the only or best way to do it, just the way I did it.

Tom S.
 
On a dovetail column mill, with the Z gibs loose enough to move the head there will always be some nod to the head. Be sure to check the tram in both X & Y with the gib locked. Always lock the Z gib after raising or lowering the head before machining. With the Z in the locked position if the Y tram is off you will have to shim under the column base to machine base.

Another area of error can be between the head and the dovetail base where the head can swivel. When I pulled mine apart to do the CNC conversion that joint was dirty and needed a good cleaning. In addition the amount of torque applied to the three locking bolts can affect the nod of the head by a few thousandths.

If you find you need to shim the column I would check the head swivel joint first.

Oh and one other thing. When I received my mill the column to base bolts were finger tight. I pulled the column and cleaned the mating surfaces.
 
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