Understanding KMotion parameters

Moderators: TomKerekes, dynomotion

Post Reply
Posts: 69
Joined: Tue Mar 30, 2021 8:07 am

Understanding KMotion parameters

Post by RogerFroud » Sat Jun 05, 2021 11:21 am

I'm putting this as a separate thread because I'm sure others will be as confused as I am and it might help as a handy reference.

As far as I understand it, the configuration of an axis is done as follows...

1) KMotionCNC is not involved in this until the basic setup and tuning is done. Then the axis perameters are set in the Trajectory Planner which tie the number of steps to the actual distance in Inches (even if the machine is Metric)

I'm sure I'm not the only one who was confused by KMotionCNC calling this the Tool Setup since it's actually the Machine Setup and has nothing to do with tools!

2) KMotion is used to set up the parameters for each axis. Those end up in the Initialiisation 'C file, which doesn't need to be compiled when it's used by KMotionCNC. That appears to be done when you launch KMotionCNC.

3) KMotion uses the Config & Flash, Step Response and Filters windows to set up and tune the axes. Annoyingly, these windows are always on top of the KMotion window, so you have to move them around to access other KMotion functions.

4) KMotion shares information between the Config & Flash, Step Response and Filter Screen so that the axis response can be experimented with just by changing the values in the respective windows without having to save them anywhere.

5) The axis needs to be enabled, which you can do using the Digital I/O screen, or it can be done by the Initialisation 'C' file. I've used the example 'C' code to make the Enable bit I'm using follow ch0->Enable in an endless loop. However, for this to work, you need to use the Save, Compile, Download and Run button.

6) The values you end up with need to end up in the 'C' initialisation file which isn't done automatically. You have to open the 'C' initialisation file and press the Export All to Open C program button. This one button saves the parameters from ALL of the Config & Flash, Step Response and Filters screens to the 'C' file, regardless of whether the other screens are open or not. Once copied, you're prompted to save the 'C' file.

7) The Filters screen has a Copy to Clipboard which to my mind implies that you manually have to do that. However, that's not the case as I've explained above. The Config & Flash window has the Copy All button on it, but if that was closed, you wouldn't be able to do that function.

Once you understand how these separate part work together, it's easy enough to use. However, it's neither obvious or intuitive in my opinion, and could benefit from a rewrite.

Post Reply