When will the center line tool be fixed? I just downloaded ver 1.4a and it still is bad. Way too much Z action. I'm running a CNC Router, not a sewing machine.

 

The video does not address the problem. I managed to get rid of most of it by using repairBL and changing the cut direction 'Overhead Gantry' repeatedly. It's still a bug and if it's "non trivial", it should be fixed!

 

I often had the issue of the "needling" (sewing machine syndrome), or backtracking, and, as Swarfer mentions above, it is due to some aspects of SketchUP which SketchUcam handles as best as it could. I played with this for the longest of time... Some of it was triggered by "excessive" editing of my designs interlaced with SkectUcam. Some of it is due to my using too much precision (ex: 96 segment circles rather than default of 24), etc. In other words, partly my being green as well. However, editing a design with no changes in SketchUcam, moved the backtracking around. Sometimes it disappeared. Other times it just got worse. SketchUP was moving things around which seemed to trigger backtracking. Regardless, it is definitely a pain. But there are ways to work around the issue.

As Swarfer indicated above, there are a few tricks to minimize the backtracking. The best one to date, from my experience, is using BZpolyline The Repair/Phlaten is not as consistent in the results (my own mileage). Weld is a dice throw. Introducing tiny splits quickly becomes a pain. I use 1/64" so I can see them when zooming in and still be small enough a 1/8" bit would not leave much of a trace. But some of my design had severe backtracking - a job which should run in minutes took hours. To find the right combination of tricks often took hours, if not days. So I gave up and went with the divide and conquer approach, along with the BZpolyline 'fix'.

I pass most of my design through SketchUcam in 3 to 7 steps : inside cutouts, outside cutouts and one or more for details (contours, etc.) One file - the master copy, is the design. Once 'clean', I make a copy for each step. Some make the copies within the same file, I prefer having a few files to juggle. This lets me control the order aspects are milled/routed by joining the individual Gcode files as I want using SketchUcam. This also lets me change certain aspects of a design (ex: customize markings on a game board) without having to regenerate the entire job. Manual tool changes can also be done this way, but each tool becomes a separate job with same X/Y zero. Just need to zero Z between tools... There's lots of opportunities with this divide and conquer approach.

In extreme cases, I would use a Gcode editor to manually remove the backtracking. I would do a few other 'enhancements' to speed up jobs ... For example, I would not pull all the way up to the 'safe height' (SketchUcam actually does two steps on way down : rapid to just above surface and then feed into the material; where safe to do, I would pull up to just above the surface or previous cut instead of all the way up). But I love getting into these details ... OCD, sorry.

The best news of all, Swafer most recently tweaked SketchUcam to reduce the backtracking. Testing against some of my 'trouble' files shows a great improvement. In many cases, the backtracking disappears. In other cases it reduces it substantially. In no case did it make things worse. Editing the design in SketchUp didn't seem to move backtracking around since it was reduced or eliminated.

I'll be sticking to SketchUp and SketchUcam for a while longer, especially for 2.5D needs. True 3D work would need more ... but I'm not there yet. Do not forget, these are tools ... The user is a definite part of the magic.

Wait for the next release of SketchUcam. I'm certain it will reduce if not eliminate your "sewing machine" symptoms.

 

Woo Hoo, Centerline tool works now with Ver 1.4d. Knocked off 1000 lines of code in a 5600 line file, for my Christmas Orniments.