# Can't work out where the R6 starts as it blends into the R38

**URL:** <https://cnc-routers.org/t/cant-work-out-where-the-r6-starts-as-it-blends-into-the-r38/57>\
**Category:** CAD/CAM Software\
**Created:** [October 7, 2026, 2:28pm UTC](https://cnc-routers.org/t/cant-work-out-where-the-r6-starts-as-it-blends-into-the-r38/57 "2026-10-07T14:28:04Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![jess](https://cnc-routers.org/user_avatar/cnc-routers.org/jess/32/52_2.png) [@jess](https://cnc-routers.org/u/jess)\
**Post date:** [October 7, 2026, 2:28pm UTC](https://cnc-routers.org/t/cant-work-out-where-the-r6-starts-as-it-blends-into-the-r38/57/1 "2026-10-07T14:28:04Z")

</div>

I’m stuck on the profile geometry for a turned part and could use a second opinion (drawing attached).

The rest of the profile is straightforward — I’ve been doing it all with direct programming — and the R38 I can handle on its own with a G2 and I/K. The problem is the R6: I can’t work out where it begins, and where it hands over to the R38.

This will run on a Fanuc 18 using G71 type 2. I’m not after a finished program — if I know those points I can take it from there and finish the profile myself.

 ![image](https://cnc-routers.org/uploads/default/original/1X/4461d0dc9d09ed9ff285f47eb362b7ad637b8175.jpeg)