Motors missing steps on circle

[RockBoy]

Hi all

Not sure if this is the right place for this but I'm a little lost. I have recently built my first router table and have hooked up a probotix 3 axis kit to control it.

I'm using K-cam to drive the motors, and the threaded rod i'm using for lead screws is very smooth with very low torque.

When jogging (or gcoding) it around (currently just a pencil) in straight lines (no arcs) the machine is both accurate and precise. But Something is happening when i draw a circle.

Firstly even when going straight the motors are constantly making a clicking noise but not noticeably missing steps (i think i read this is normal for kcam). But when making arcs the motors look like they are in pain they knck arround alot and seem to skip steps. For example i would have thought when coming in to a arc one axis would ramp down linearly but i'm not seeing that.

To look at it seem like the motor has three speeds and when its stuck between speeds in skips and goes a bit mental (not smooth). The result is a circle which looks like it has been very slightly compressed into a octagon.

The pencil however ends up exactly where it started. I have a feeling this is software related, i tried installing mach3 but kept getting errors so i gave up.

I'm not really sure what to try next and would appreciate any suggestions.

Thanks

[mlind]

Hello,

On your circle file is it a .dxf file that you import into kcam? First try this file. It is 2 circles a small one and a big one. Under kcam menu import the dxf file.

Also just a guess as I had a similar problems with a different driver board and I set the DIP switches to I beleive micro-stepping and had no problems after that.

You might also check in kcam to make sure you ran sysem timing as that helps the motors run more efficiently on your system.

On your X,Y,Z speeds under table settings set feed rates to 8 for x,y,and z,... and also set the maximum speed rates to 10 for each axis and set the ramp rate to 5 and maximum ramp rate to 10 ....make sure read about the backlash settings. I forgot what I had mine set to. I know its slowing down your system but this will help you see what you are doing as well as testing the hardware. If it works at slower speeds then you know you have a hardware/electronic problem.

If all the above doesn't help Try contacting Kelly at KCAM. It might take a a day or so for him to get back to you but the support from KCAM is outstanding. Make sure and join the KCAM forums so you can post questions there too. There are Gurus both on CNCZONE as well as KCAM forums.

Hope this helps.

[RockBoy]

WOW, so i did the easiest thing first which was to change my motors to half stepping and it seems to have worked. Thanks heaps.

The motors are still knocking alot and are quite loud, but i guess i won't notice that once i have a router on it.

[mlind]

Great,

You are welcome...

Make sure you run system timing under the setup tab in KCAM as it will tune your motors to run more fficiently. It helps and will also help with speed.....

WOW, so i did the easiest thing first which was to change my motors to half stepping and it seems to have worked. Thanks heaps.

The motors are still knocking alot and are quite loud, but i guess i won't notice that once i have a router on it.