Jerk policy

Tinchus

Hello, command M566 has the option for policy 0 or 1. It is not being clear to me the difference. When should I use policy 0 or policy 1?
Thanks in advance

alankilian

@tinchus

The default jerk policy is 0, which replicates the behaviour of earlier versions of RRF.
(jerk is only applied between two printing moves, or between two travel moves, and only if they both involve XY movement or neither does). 

Changing the jerk policy to 1 allows jerk to be applied between any pair of moves.

So if you want the jerk policy to be implemented between a printing move followed by a travel move, or a travel move followed by a printing move, you set the policy to one.

CCS86

The only time I noticed a functional difference is when using "coasting" (a Cura feature). With jerk policy set to 0, there is a small stutter at the start of the coasting move. Jerk policy 1 avoids this.

Tinchus

@alankilian this the thing taht is not clear to me. So, what happens when a travel move finishes and a printing move follows this travel move, what jerk is applied to the start of that printing move if jerk policy is 0?

alankilian

@tinchus As I understand it, no jerk control will be applied in your example.

Phaedrux

Policy 1 will allow for a faster transition between travel and print moves because a minimum jerk speed is applied.

Policy 0 would basically be a dead stop between the moves.

It's most noticeable with a fast travel speed and lower print speed.