Machine Shop Home  
  Introduction  |  Safety  |   Milling Machines  |  Speeds/Feeds  |  Cutting Tools  |  Broaching |  Projects  |  Tests

milling.jpg (4974 bytes)

"Milling Machines"
Squaring

Milling  Home

Squaring a part on a Vertical Milling Machine

Squaring a part is the most basic skill a person can be expected to perform on a milling machine. Even though squaring is one of the more basic skills in milling, it is perhaps the most important. If the part does not start out square, the rest of the operations that are performed on this part will probably not be correct as well.

As with any other milling operation, cleanliness plays an important role in the outcome of the quality of the part. Chips, burrs or dirt between the part and the holding device will cause the parts you are working on to not be square or otherwise incorrect. After you have deburred your part, and cleaned your vise, lightly run your hand over them to make sure they are clean and free of burrs.

We will be squaring up the part in Figure 1. To hold the part out of the vise far enough to machine the face, we will use parallels. If you are unsure of how parallels are used, see Figure 2.


Figure 1


The most important aspect of squaring up a part is the sequence in which you machine the sides. When beginning to square a part, start by machining the largest side or surface first. We will use this surface as our base or reference side. In Figure 1 this would be either Side C or Side A. Place side D down on the parallels. We will start by machining side A. Take a light clean up cut off of side A (Figure 2). Make sure that the cutter rotation is toward the solid jaw of the vise (Figure 3).


Figure 2


Figure 3


After deburring the part and cleaning the vise, we will take and place side A against the solid jaw of the vise and take a light cut off of side B (Figure 4). This will make side A and side B square to one another. After deburring the part, use a solid square to check side A against side B. They should be square to one another. If they are not, check for burrs or dirt in your setup.


Figure 4

Now take and place side B against the solid jaw of the vise and take a cut off of side C (Figure 5). On this cut you could take the thickness down close to the finish size, leaving just enough for a finish cut. This will make side A, B and C all square to one another. As you can see we are rotating the block, in order, one adjacent side at a time (Figure 6).


Figure 5


Figure 6

Use a solid square to check side C against side B. Now take and place side C against the solid jaw of the vise and take a cut off of side D. On this cut you could take the Width of the part down close to size. Leaving just enough for a finish cut. Rotate the part one more step and take finish cut off of side A. Rotate the part one more step and take finish cut off of side B. 

The block should now have four square sides which are machined to size. 

Finishing the ends can be a challenge, depending on the size and shape of the part. If the part is short, you can merely stand the part on end and use a square or dial indicator to hold the part squarely in the vise (Figure 7). Once the part is square in the vise, a face milling cutter can be used to machine the end. Once the first end is machined, check the end for squareness using a solid square. If the first end is square, place the part down on top of parallels and machine the opposite end to length. 


Figure 7


Figure 8

If the part is long, but not too thick, you can place the part in a vise and side mill the ends to length (Figure 8). 

The vise would have to be indicated first to assure the the part is square to the cross travel of the machine.

If the part is thick, you could use an angle plate to hold the part on a vertical milling machine (Figure 9). 


Figure 9


Figure 10

On larger pieces, a horizontal milling machine is probably the best style of machine to use when squaring the ends of the part (Figure 10). 
Again, if you are using a vise it would have to be indicated first to assure the the part is square to the longitudinal travel of the machine. If you are setting up the part in an open setup using clamps (Figure 11), the part, or in this case the locating device (parallel), would have to be indicated first to assure the the part is setting square to the longitudinal travel of the machine. The parallel is used, in this instance, to allow the operator to turn the part around to finish the other end without having to re-indicate the part.


Figure 11

  Top