G61 or G64

[sco]

I have been running my gcodes with g61(constant contour off) for no reason other than I am still learning. I recently found G64 (constant contour turned on). I ran my machine with G64 and the machine now does nice smooth curves! GREAT! (curves used to be jerky with G61)

My question is...
Is there a down side to using G64?

cheers
sco

[svenakela]

You get smoothness, but loose precision.
With G61 the machine will go to the given point before it goes further to next point, with G64 the machine will turn to next point before it reaches the first points coordinates. This gives a smoother run with higher speed.

[phungi]

http://www.machsupport.com/docs/Mach3_CVSettings_v2.pdf

[svenakela]

There is some reading here as well.

This picture explains it. It's kind of small, but the dark lines are the G-code path (G61), the yellow lines are G64 with different tolerances (G64 PX.XX for EMC2 coding standard).

[sco]

Thankyou gents. I appreciate your time.
cheers
rosco