Getting going on Vcarve pro, v11.
I have the 5 Pro so I’ve selected the carbide create atc inch. I design in inches so I assumed that was right.
Is there any benefit to (designing in inches) but using atc mm post processor instead? Running through Carbide Motion?
GRBL is inherently more precise using mm, so using a mm post-processor gains that. It can help avoid a certain errors that happens when outputing Arc commands.
As @mhotchin said because GRBL uses mm, using a mm post-processor will keep things more precise in it’s movement commands. Also note that using a mm post-processor doesn’t require that you use it in your Vectric software. Thus, you can design in inches and use a mm post-processor. This is what I do.
When using inch you can get rounding errors that cause anomalies. As the above said the MM is more precise because the stepper motors are running in MM. The inch measurements are converted to MM anyway and that is why you can get rounding errors when running in inch.
I have used inch all my life and am considering changing to MM to get more used to it. MM is a very logical measurement system but old habits die hard.
Thanks guys. Those are absolutely the responses I was hoping for; not only confirming which is preferred but ALSO an explanation as to why.
You can increase the number of decimal places in the Vectric inch post processor, a pretty simple edit, to get around this. It also fixes the grbl error 35 that can rarely happen (only in that one job you need done right now) with G2/G3 arcs, I’ve only seen that reported with Carveco, Vectric spun off from their predecessor.
That’s only if you want to stay with the inch post processor and not switch PP only. Metric has no inherently better precision than inches, but dividing inches by 25.4 can pick up the equivalent of an extra decimal places.
I haven’t had any problems using Vectric’s inch post processor to generate code for my Pro XXL, whether I designed the part in mm, or inch. The same thing for any code I post out of Fusion360.