Dynomotion

Group: DynoMotion Message: 9414 From: Tom Kerekes Date: 4/13/2014
Subject: Re: Jerky movement when running G-code in Mach3. Jogging smooth. [3
Hi Frank,

To decrease the following errors you will need to tune the servos better.

Before tuning, find your system's limits for Velocity, Acceleration, and Jerk. The move you posted is too small to reach full velocity.

Also determine the resolution of the axes (counts per inch).

Please read through this thread:
http://www.cnczone.com/forums/dynomotion-kflop-kanalog/215344-anilam-supermax-frankenstein-project-using-dynomotion-kflop-post1460988.html#post1460988

To reduce following errors you will need to increase gains.  The uneven motion at constant speed could be from a number of reasons such as just trying to move too fast.  You will need to determine the reason.  Adding D Gain by itself will tend to slow down the response (unlike P and I Gains).  But it should help stabilize the system so higher P gain can be used.  Unfortunately you can not just try one thing at a time.  Whenever adding D Gain you should also add a 2nd order Low Pass filter of 1000Hz Q=1.4 into the right most (last) filter otherwise there will be "spikes" in the output.

Finally add some I Gain.  Start with a value of 0.0001

Not sure what the big jolt could be maybe commanding too high of a speed.  But you should not try to run G Code until after you have parametrized and tuned your system using KMotion.exe.

HTH
Regards
TK