Using a model mill instructions
you ever want to check alignment of the key to the column bed, mount a dial indicator in 
the spindle. Raise and lower the head while reading the vertical edge of a precision 
square. Adjust the rotating column until there is no error as the indicator moves up and 
down the square. Now read the table with the indicator. If the slot and key are perfect 
there shouldn't be any error, but in most cases there will be a small amount. This can 
usually be eliminated by taking advantage of what play does exist in the alignment key 
and slot. With the cone point set screw loosened slightly, tap the headstock with a plastic 
mallet to take out play in the direction you want to go. Then retighten the set screw. 
FIGURE 6-Fine tuning the headstock rotation alignment with a machinist's square and 
dial indicator. The headstock pivots on the saddle pin. Even with the alignment key in 
place, slight adjustment can be made to get the headstock perfectly square. 
Making final adjustments 
The rotating column and tilting adjustments can be finalized so the indicator reads "0" as 
the spindle is rotated, however the error we measured when checking the table flatness 
could be accounted for now if need be. If the pointer on the back of the rotary column 
disk doesn't line up with the zero mark, loosen the screw holding it in place and reset it to 
indicate zero for future reference. 
Your machine is now "indicated in" and ready to use. As you get a feel for your machine 
and go through this adjustment procedure a few times, the time it takes to get good results 










