Newbie- RTCP

[emsee]

Is RTCP part of Cam software or Control?
How to find out MasterCam or a particular control support RTCP?

Thanks

[Superman]

RTCP is the control of the programmed tooltip in relationship to the part's origin, even when rotational planes come into play and are moving at the same time.

This is method should only be considered if the machine and control has this option enabled

A basic 5-axis machine without this function would need the work origin placed at the pivotting point, and the stock/part placed in respect of that pivot point and then programmed. Any repeat of that part has to be setup identically or the program will fail.

This RTCP method allows you to place the work origin, either on a part/stock or fixture, anywhere in space and the point the tool has to move to is calculated continuously from it's current position back to a continuously moving "fixed" origin - this is the hard bit to understand about TPC (Tool Point Control).

In Mastercam, you program to suit the machine capability, the post may need customizing to utilise this function and output additional code.

To program for RTCP, you only need to place the part and stock in relation to a WCS origin for that setup, and that WCS wil need to be used for all operations for that setup, the post should take care of everything else ( this, by the way, is a standard mastercam programming method - with or without RTCP )

Without RTCP you can only do 3+1 or 3+2 programming, you cannot use 5-axis paths---uless you have the origin at the pivoting point of the machine.
The more accurate that this pivot point is set, for any method, the better blends you have, and a more accurate part will be created,---it'll look good too.

[emsee]

Your explanation is very instructive. It answers my question!!

[dacar1]

As superman said, RTCP is a feature of the controller for 4/5 axis simultaneous machining. It has different names in different brands of controller. Eg. Heidenhein calls it TCPM (Tool Center Point Management), Mazak calls it TTPC (Tool Tip Point Control), etc..

A basic 5-axis machine without this function would need the work origin placed at the pivotting point, and the stock/part placed in respect of that pivot point and then programmed. Any repeat of that part has to be setup identically or the program will fail.

I also want to add that without RTCP, 5 axis machining will not be as accurate..

You may also want to read following thread:
http://www.cnczone.com/forums/kitamu...re_offset.html

[budgieW]

""I also want to add that without RTCP, 5 axis machining will not be as accurate..""

Why?

[dacar1]

RTCP is not only about placing workpiece zero anywhere in the machine tool. It applies continous compensation so that the TOOL TIP is always on the programmed path in operations involving rotary axes.
I have tried to illustrate 3 cases in the attached picture. Green is the path with RTCP. Red and blue are paths without RTCP. And blue path shows how generating more points in toolpath may reduce path error.
You will experience these effects more when you have big rotary axis movements (eg. 10-20 deg.) in your simultaneous operations.
With small angular steps, errors may be negligible.
Finally, these issues only applies to table-table type machine tools. Its very very hard to do 5 axis simultaneous with a machine tool having a rotary head without RTCP.