Universal Tuning value

I upgraded my software and I see the "Tuning Value" is now one global system setting, so I assume that once set the firmware calculates the the compensation needed for different speeds.

I ran the tuning wizard and found that my optimum tuning value is past +10. I ran some test lines and inspected the results under my microscope and found that tuning +18 gives great results.

Now the big question is. Should I be concerned? Reading up loose belts can cause this, but my belt is correctly tensioned and adding more tension does not get me a lower number. I also checked the idler wheels, all four of them and they have no play, bumps or wear. The stepper feels good too, no play.

Any ideas?

Cheers
Keith

(.-.)

Universal Tuning value