2-Z Options

Dual Z, Tandem Z, Independent Z

Dual Z:

In most cases, a second Z will be used to provide an additional cutting tool that is ready to use without having to stop and do a tool change – a poor-man’s tool changer. This option is called a “Dual Z” .

With a Dual Z, two Z axes are mounted as close together as possible on a single, special, Z-car. NOTE: that even though the Z’s are as close together as possible, the cutters are still about 7” apart. Thus because the travel of a YZ car is only about 1” beyond the nominal cutting area, a Dual Z requires a tool that is a foot wider in size, in order that both Z’s will be able to cut a common area of the intended nominal size. That is, to assure 48” width working coverage a Dual-Z tool needs to have a 60” width. To assure 60” width working coverage a Dual-Z tool needs to have 72” width.

A Dual Z is our primary 2-Z option. The other two offerings which follow are for very special cases and are not appropriate unless fully understood.

[See Coverage Table for details on work area.]

Tandem Z:

In occasional situations it makes sense to consider cutting duplicate parts at the same time. For this we’ve provided a “Tandem Z”. With this arrangement, the idea is that one Z moves exactly the same way that the other does, offset to a different Y location by the length of the spacing between the Z’s (two positions shown below). In this case we have a primary YZ car, and a secondary YZ that does not have a motor, but is ‘yoked’ at a constant distance to the first. The two parts that will be cut at the same time are offset from each other by the distance of the yoke between the two Z’s

The offset distance of the secondary YZ car can be altered by changing the length of the yoke. It is also relatively easy to remove the secondary YZ car and have a normal tool with standard footprint.

The coverage area of the two Z’s is limited and defined by the spacing between the two cars. This is something that the user will need to adjust in order to optimize the production process. Selection of table size also depends on the nature of the production process. Note that with PRS tools, it is possible to remove the tandem car to get normal use of the tool back. A tandem Z can be added at any time to a tool, given an understanding of the space compromises. Note that PRSalphas have plenty of power to drive the tandem car. However, PRSstandard tools will have limited power to push two cutters simultaneously.

[See Coverage Table for details on work area.]

Independent Z:

The “Independent Z” is really a special beast: Basically two complete YZ Cars on the same Y rails. This solution would be used in the same way as a Tandem Z, but it would offer the advantage of automating the adjustment of the spacing between the two duplicating Z’s and would offer the option of driving one Z fully out of the way when not being used (though the clearance would be of limited value unless there is a 72” Y width).

There is an additional complexity with the Independent Z arrangement in keeping the two axes from running into each other – a special limit switch will need to be set up. Because the second YZ car is heavy and has an engaged motor, it is difficult to remove an Independent Z to get back full use of the tool. NOTE that it takes a 72” width tool in order for each of the two Z’s to access a common 48” width.

We can think of very few cases that would warrant purchase of Independent Z’s. It does sound cool to have two cars moving around like this. But it has very limited practical value.

[See Coverage Table for details on work area.]