Changes

<div class="yiv2818182665class" style="color: #000000; font-size: 13.3333px; font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; background-color: transparent; font-style: normal;"><span class="yiv2818182665class">The</span> KFLOP parameters are used for 3rd order motions.   These include things like:  Jogging, Homing, and GCode Rapids (G0).  The units in KFLOP are in counts or steps.<br /><br /><span id="yui_3_16_0_1_1445622719616_3320" class="yiv2818182665class">The KMotionCNC parameters are used for 2nd order (</span><span id="yui_3_16_0_1_1445622719616_3321" class="yiv2818182665class"><span class="yiv2818182665class">infinite </span>Jerk) coordinated motion paths.  These are GCode G1,G2,G3 continuous paths.  The units are in Inches (or in some cases degrees).   Note there is an Option in KMotionCNC "Rapids as Feeds" where these parameters will also be used for Rapids.  But this option should only be used for highly non-linear Kinematic Systems which can not take advantage of faster/smoother 3rd order point to point straight line Rapids.<br /><br /></span></div>

<div class="yiv2818182665class" style="color: #000000; font-size: 13.3333px; font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; background-color: transparent; font-style: normal;">[[File:MaxVelAccelPower.png|none|link=|485x361px]]<br />The Step Response Screen always performs 3rd order motion but 2nd order motion can be simulated by temporarily setting the Jerk to a huge value (1000X the acceleration value).  In general reducing the Jerk value will result in longer times to perform motions, but often the improved smoothness will permit higher maximum accelerations and velocities to be used resulting in overall shorter motion times.  An analogy might be how you might stop more quickly in a car, without skidding or spilling your coffee, by applying the brakes harder in a more gradual manner rather than slamming on the brakes.<br /><br /><span class="yiv2818182665class">Make</span> sure when testing the size of move is long enough for full acceleration and velocity are achieved.  As a A common mistake is to have Acceleration or Velocity Settings set to too high for your system but when testing a short move there is no indication of a problem.  The plot mode of Velocity Output  vs Time can be helpful to verify full Velocity is being achieved.<span id=".C2.A0" class="mw-headline"> <br /> <br /></span></div>

<div class="yiv2818182665class" style="color: #000000; font-size: 13.3333px; font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; background-color: transparent; font-style: normal;">The idea is that a motor axis has torque and speed limitations and you should determine and understand what they both are for your system. Available motor torque drops off with higher speed. At some speed the motor will not even be able to generate any torque at all. Motor torque is required to accelerate the axis. We need to make sure that no combination of velocity and acceleration will ever cause the axis to fault/stall/fail. So there is often a complex set of speeds and accelerations that will work ok that form an envelope of workable speed and acceleration. So one nice thing to know is top speed possible. It is like taking your car out on a long straight highway and gradually accelerating to find the max speed is 100MPH. You will then know that ever attempting a speed over 100MPH will always fail. Also speed should probably be limited to something like 80MPH to allow for margin and to allow reasonable acceleration up to that speed. The reason for performing the top speed test at low acceleration is to avoid a failure because of not being able to accelerate at the specified rate. So we want to set the acceleration to a low value so it will not be a limiting factor when determining top speed. However if we set the acceleration so low with a short trip distance we will never go very fast and the speed test will be meaningless. This should be avoided. Change the Plot type to Velocity, Output, vs Time to clearly see if this is the case.  You may want to turn off Measured Velocity if it obscures viewing the Commanded Velocity<br /><br />For example to accelerate to 700,000 counts/sec at an acceleration rate of 700,000 counts/sec^2 would take 1 second. And then to slow back down would take 1 more second. So at least 2 seconds of motion would be required to get to full speed. A 100,000 count move (2 inches for a system with 50,000 counts/inch) takes much less time than that. Furthermore with a relatively low Jerk setting (1e6). This means the acceleration will be applied gradually over 0.7 seconds. This means an even much longer time and distance would be required to achieve top speed.<br /><br />Here is the method to follow to find 2nd/3rd order motion profile limits:<br />(note every system is different and will vary based on resolution, motor size/type, mass, etc...)

<div class="yiv2818182665class" style="color: #000000; font-size: 13.3333px; font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; background-color: transparent; font-style: normal;"></div><div class="yiv2818182665class" style="color: #000000; font-size: 13Now that the system is properly tuned and reasonable Acceleration, Velocity, and Jerk are set the motor Position should always follow the commanded Destinations accurately with only small errors.3333px; font-family  By Plotting Position Errors under various conditions (Distances) you can get an idea of the worst case following errors under normal conditions.  The Max Following Error Parameter should be set to a value slightly larger than the worst case following error (ie 20~50% larger).  In this case if anything abnormal occurs: HelveticaNeueie. The axis hits an obstacle, Helvetica Neuecommanded at too high of a speed, Helveticaservo goes unstable, Arialhardware/electronics failure, Lucida Grande, sans-serif; background-color: transparent; font-style: normal;"> a Following Error will be immediately detected and the axes disabled.</div>