Setting up your milling machine for use
Setting up and aligning your you machine and working-hold fixtures is one of the most important stages in getting ready to start milling. If the piece that you are milling isn't locked in properly the machine can ruin the piece or it could cause injury to the operator should it come free from the vise.
There are a few alignments that you will want to pay attention to and make sure that they are alighted properly. They are, table alignment, head alignment and vise fixture alignment.
The table alignment should be checked every time that the table is being returned to the 0* position. It is a good practice to not trust the graduation marks on the machine when you need to do accurate work. When ever you are working on a project that needs accurate angles.
What you are going to need is a rigid mounting dial indicator mounted on the table. It has to be mounted on the table because you are measuring the angle of the table in relation to the column of the milling machine. This will give you a much more accurate reading for the angle of the table.
On a vertical milling machine with either semi universal or universal heads should be checked before preforming a job that requires accurate alignments. To make sure that the alignment is correct you will need to follow a few steps. First you should clean the table and place a flat parrallel plate on it. Connect the dial indicator to the sprindle and feed the spindle down, with the dials lunger at the operator's right or left side until is ragisters to about 1/4 of the operating range, and get it to zero. Rotate the spindle carefullly one rotation on a universal type head the readings will vary on both of the axes. When you are adjusting the head on a universal milling machine you should adjust it one axis at a time to keep it aligned. When it is aligned make sure that you tighten all the locking bolts.
The last alignment that you should check before beginning your project is the vise and fixture alignment. This is the reference surface, where the piece you are going to be milling will be held. To align it attach the dial indicator to the arbor of a horizontal milling machine or placed in the collet of a vertical milling machine. To align the vise you will want to use the following procedure. Start by cleaning all the parts, making sure that there are no nicks on the surface. Clamp the vise in the what appears to be the correct position. Take the dial indicator and bring it into contact with the part that is going to be aligned. Slowly move with in the operating rance until its at zero. Cross slide the jaw to the full length and make note of the variation in the indicator reading using a soft hammer. When you see that the indicator shows no deviation, tighten the blots and recheck the indicator.
Once everything has been checked you should be all aligned and ready to go.
on Feb 06, 2014 | Tools & Hardware - Others