Question UCCNC backlash

Hi,

Prior to using my Stepcraft 420/2 for pcb milling, I have been attempting to set the profile backlash limits on X and Y axes by drawing groups of lines in parallel to each of the axes

In the course of setting the profile parameters, I found that both X and Y axis backlash settings are using the X value set in the profile - the Y value has no effect on either axis.

So as to see any backlash, I created G code for two of groups of lines (one drawn in X direction and one in Y ) with alternate lines drawn approaching the required position in opposite directions. Any backlash results in obvious pairing of alternate lines, and the profile value is then adjusted to give even spacing between lines.

To be certain that flexing of the pen did not mask any backlash, I made a ballpoint refill holder out of brass and reamed the ballpoint exit to limit the sideways movement to less than 0.001" (25 microns). Initially both axes had a backlash of about 0.2mm, after adjustment using a compromise setting for both ( ), I managed to get both axes to better than +- .002" (0.05mm) backlash. Not perfect, but a lot better than when I started.

To do the measurements I used a small microscope which has a 0.001" engraved reticule in the eyepiece, so I am reasonable sure of the values above.

Hi Peter - what version of UCCNC are you on? We did a project last week with varied backlash settings on all axes?

The new version of UCCNC V1.1XXX has a new backlash algorithm. If you are 1.0034 give us a shout and we'll send over updated profiles and sofware.

Hi Rory,

UCCNC "About" reports software version 1.1012 !! So I am way out of date - installed this from the USB stick that you sent with the 420 kit.

Sorry - I stand corrected, on second thoughts I downloaded it from the UCCNC website. I had a problem with getting the license to be recognised, so I downloaded the complete installer which was said to be the latest version - it clearly wasn't, aint hindsight a wonderful thing!!

Thanks for your quick response.

Cheers.

Peter

After finding I was inadvertently running a very old revision, I installed the brand new V1.1026 today. The auto-installer worked like a dream thank goodness

This revision certainly doesn't have any problems with the backlash compensation routine, so I can now think seriously about the Eagle to G-code conversion process. I wonder if I dare use parts with a 0.5mm lead spacing!!

Peter

Hi, I'm having the same issue with the Backlash compensation on an 840 machine. Could I get the update as well?
I have UCCNC version 1.1019.
Thanks

Hi Rory
I'm on version 1.0031, could I get the update as well?

Cheers

coops3d wrote: Hi Rory
I'm on version 1.0031, could I get the update as well?

Cheers

kinasmith wrote: Hi, I'm having the same issue with the Backlash compensation on an 840 machine. Could I get the update as well?
I have UCCNC version 1.1019.
Thanks

Download it here: http://cncdrive.com/UCCNC.html

Hi

The UCCNC software has been up-issued at V1.1027 very recently.

I wonder what's changed - must investigate this new version soon!

Peter

peterg1000 wrote: Hi

The UCCNC software has been up-issued at V1.1027 very recently.

I wonder what's changed - must investigate this new version soon!

Peter

If you mail the developer he'll send you the changelog. I did it once