Do you know that CAM-POST can automatically switch between Polar and Cartesian interpolation to avoid over-travel errors?

The LIMIT/POLAR command defines conditional Polar interpolation, which enables the post-processor to automatically switch between Polar and Cartesian interpolation as required to avoid over-travel errors. Mill-turn centers often support native polar interpolation. CAM-POST can emulate polar interpolation on a milling machine by rotating the part (with a rotary table) in place of a linear axis.

For example, the machine shown in the image below has only 60mm (2 3/8”) of Y axis travel in the negative direction, but significantly more Y axis travel in the positive direction. This type of machine is an excellent candidate for automatic Polar/Cartesian switching.

Do you know that CAM-POST can automatically switch between Polar and Cartesian interpolation to avoid over-travel errors?

The LIMIT/POLAR command defines conditional Polar interpolation, which enables the post-processor to automatically switch between Polar and Cartesian interpolation as required to avoid over-travel errors. Mill-turn centers often support native polar interpolation. CAM-POST can emulate polar interpolation on a milling machine by rotating the part (with a rotary table) in place of a linear axis.

For example, the machine shown in the image below has only 60mm (2 3/8”) of Y axis travel in the negative direction, but significantly more Y axis travel in the positive direction. This type of machine is an excellent candidate for automatic Polar/Cartesian switching.

The complete LIMIT/POLAR command syntax is shown below.

We can use the following command to tell CAM-POST to use polar interpolation, with any available rotary axis, so as to keep the Y axis output in the range -60:500 mm. The “SCAN,ON” couplet causes CAM-POST to be more proactive in determining when polar interpolation would be beneficial.

LIMIT / POLAR, AXIS,AUTO, YAXIS,-60,500, SCAN,ON

The two videos below show the effect of running the same program with and without automatic Polar/Cartesian switching.

With MODE/POLAR (good output)

Without MODE/POLAR (bad output)

Benefit to User
Over-travel conditions can be avoided by having the post-processor automatically switch between Polar and Cartesian output methods.

For more information or comments, please do not hesitate to contact Phil at TechTipTuesday@icam.com

Get an ICAM Productivity Tools Demonstration

If you already know which solution you need, and have information on your machine, click on the button below to build your custom quote!

If you wish to get in touch with one of our representatives, click on the button below and we will contact you back shortly.