Karsten thanks so much. Today I am going to try with the G3 cube. I remember you said you used two rails and one profile in an oldest post.

Now you did a new technique I think. With 8 profile and 2 rials and rebuilding.

I will come back with results of your first attempt ( since that rebuilding and making 8 profiles for each groove...will be an experiment that will need more time).

Thanks so much!