The main difference between 7018 & 6011 is the arc length,,,7018 is a drag type rod,,short arc distance 1/8 or less,,6011 is a long arc length rod 1/8 to 1/4 inch,,,using arc force on a 6011 rod will possibly have more varied results because of the arc length range and maybe harder to dial in as a result,,,I think you have answered your own question and I would try zeroing out the arc force when using that rod,,see if that improves your result and let us know...I have never used that machine so I'm only guessing...
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