Double Column Machining Centers: Five-Sided vs. Five-Axis

When it comes to double column machining centers, there are important differences to consider when looking at five-sided vs. five-axis functionality. Most of the Okuma double columns we sell are equipped for five-sided machining, but that doesn’t mean you also get five-axis capabilities. Five-axis means that you have five axes: X, Y Z and typically B and C that are all completely control contouring for simultaneous running. And the good news is, you can have a double column that’s capable of both five-sided and five-axis machining. But this is not a given, so it’s good to understand the distinction.

Okuma’s Double Column Machining Centers are of Two Basic Types:

• The first type is a large frame vertical machine with the table passing between the columns. The spindle is fixed and is not easily changed out. This type of machine is found in our model, MCV-AII.

• The second type is of similar construction but instead of a fixed spindle it has a ram with a spindle motor inside of it. This motor powers various spindles that are housed in what many people call “heads”. However, Okuma refers to them as “attachments”. A machine may be configured with one, two, three or more different attachments. These attachments are housed in a storage area that is attached to the machine. When the user wishes to change attachments, this task can be accomplished by simply issuing a CNC command. Okuma offers a wide variety of attachments. These attachments may be extended verticals. They may be fixed angular attachments for use in die/mold work. They may even be universal (B-axis/C-axis). These attachments are offered in a wide variety of sizes, speeds and power levels. Since these attachments are replaceable, we add the letter “R” to the “MC” designation. Suffixes indicate other characteristics of the machine. (ex: MCR-A, MCR-A5C, MCR-B, MCR-C)

Five-Sided Defined

Many, if not most, of Okuma’s MCR machines are configured with only a vertical and a horizontal attachment. When a double column machining center is configured with both a vertical and a horizontal attachment, the user has the ability to machine in either a vertical or a horizontal attitude. With this configuration, one machine can function as a both a vertical and a horizontal machine. This means that, rather than re-positioning the part, the user can possibly machine the entire part in one clamping. In other words, the user can effectively machine on five sides of a workpiece (top, front, rear, left and right). When we say the words “five-sided”, this is what we are talking about.

Strictly speaking, we are not limited to five sides because the horizontal attachments are indexable in the C-axis in increments as low as 1-degree. Also, as mentioned earlier, Okuma offers a variety of universal (B-axis/C-axis) attachments. In addition to C-axis rotation, the B-axis can also be rotated. The basic B/C attachment is for positioning only so while this is “five-sided”, it is not truly “five-axis.”

The Five-Axis Option

Not to worry! Okuma also offers full 5-axis contouring capability on its double column machining centers (our MCR-BIII machines). If the machine is pre-configured for full five-axis machining, a contouring B/C attachment can be added to the machine. This full 5-axis attachment can reside on the same machine as any of the other attachments mentioned above.

Have any thoughts to share on five-sided vs. five-axis machining? Please feel free to add your comments or questions below. Or, you can check with your local distributor or contact us directly.

Dennis Nichols is Senior Applications Engineer, Okuma America Corporation.