Drawing node count and CV settings in Mach

[motoguy]

Just last week I learned the benefits of reducing nodes as much as possible in my drawings, before importing into Sheetcam. Reducing nodes to the bare acceptable minimum, and setting the CV distance tolerance to a minimal number (I'm currently using .04...roughly 2/3 to 4/5 of kerf width) gives some really nice cuts, which stay right on the desired cut path.

In the past, I had been frustrated with my machine. I knew this machine was rigid/quick enough, as others were happily running it. I just kept rounding sharp corners! I tightened up the CV settings, but then started getting jagged looking cuts! As so many of you all already know, I finally realized the CV setting (and accel settings...I think I'm at 32 X/Y/A axis) is the key to following a line closely, and node reduction is the key to doing it smoothly (in addition to creating a smaller file). Reduce nodes, open up the CV settings enough to give a little 'wiggle', and things look great!

I know most of you know this already, but I thought I'd post my recent discovery, on the off chance another new guy needs this info as well.

[Fred1956]

I'll ask...What method do you use to reduce node count? I use Inkscape and Draft sight and have recognized what you say about less nodes being better but I have no idea how to do it... Thanks

[mcagauto]

In inkscape you can select the object then hit control +7 or path then down to simplify.

[motoguy]

I have since made a few changes. I found that having the CV at such a low number would cause the machine to pause at nodes on the drawing. This would create a small divot in each of these areas.

I opened up the CV to .19, which fixed the issue with the nodes, but led to rounded corners again. I then increased the acceleration on my machine from 32 to 40 (factory setting of 30 from Bulltear).

With this combination, it seems to keep all the corners nice and sharp, but also not pause on the nodes as it is cutting. It feels like I have found a sweet spot.

Regarding the nodes, I use CorelDraw X7. It has a node reduction tool which use that to reduce nodes in bulk. The tool automatically reduce nodes to a certain level. It also has a manual slider, which allows you to continue to reduce the nodes. As you reduce the nodes, it will show the deviation of the drawing from the original path. I previously used the slider, and reduced node count as much as I could before the path became unacceptably deviated. Now, with the CV and acceleration settings mentioned above, I find that I am not as concerned about the actual node count. I typically use the automated reduction setting, and leave the slider alone.