Hi i see this question is asked a bit but the use of the fit curve command using different parameters doesnt really yield any significant change and rebuild I find not too helpful either
Problem - Reduce point count of curves and keep accuracy
Why - so when exported as DXF to fusion the point count does not slow the cnc process
Other - why do joined closed curves in rhino split apart when taken into other programmes i.e illustrator and fusion Ive tried dxf step and igs formats
Ive seen this https://www.youtube.com/watch?v=FXiVPC8k_VE
tutorial and thats worked I dont know what I’m doing with my polylines and its rendering a non result, thanks in advance for any help
A DXF for laser and plans cutting needs to be handled very specifically.
Most CNC controllers can only use arcs or straight lines. This guide can be used to make sure the least number of are segments are used: https://wiki.mcneel.com/rhino/exporttolaser
Another option is to use something like RhinoCAM to fit toolpaths to the curves.
Thanks Scott, understood reducing point count greatly reduces processing and machining time
Rhino for modelling excellent I have a large format laser, mimaki cutters and CNC and have always used illustrator for this
however loved learning rhino and i would say if you focused on a couple of things within this software Id recommend 2d designers to use Rhino over adobe seriously
So are you telling me rhinocam is the answer and theres no real effective way of reducing the point count within Rhino
the purpose of these lines over the surface are for the vcarving tool path how does rhinocam approach vcarving does it have that function?
These are not polylines - they are degree 3 NURBS curves (splines). I see in another thread that you were projecting these curves to a surface or something, that is probably how they got that way. Running SimplifyCrv on them can simplify them somewhat, although they are still not polylines, the segments are actually slightly curved - I measured 0.017mm difference from a straight line at the middle of one segment.
There are also a bunch of overlapping segments in places, not good for laser cutting.
So, the first thing to look at is always the quality of your original curves. Then the next thing is to look at your export settings. Depending on how your export scheme is set up, anything that is splines will be broken up into polylines using some criteria. Those may end up being be too fine or too coarse, if you do this only on export, it’s hard to know unless you re-import the file and check the result.
A better tactic might be to reconvert all your curves to lines and arcs in Rhino before exporting. As I said SimplifyCrv will get you part way there, but for some of the splines in your file you will also need to use the Convert command.
The link Scott posted above is a rather old article, but it should still be useful.
Hey thanks Helvetosaur ok is that what they are after changing 2d Curves, splines, I want the lines for the cnc to read each closed shape which allows the vcarve function to centre the tool inside every shape - and yes the surface under the lines is not flat, im still learning this software thankyou for the right terminology, THANKYOU im going to try your recommendation now see attached a section of the file with the surface under it, i’ll flick up a 3D render when I get it into fusion trying to get it sorted to machine tomorrow
Yes but it really helps to describe things with the right name so people get the right message thanks for opening my file, I learnt alot today when you say degree 3 NURBS curves what does the 3 mean (is it just for 3D) or are there different levels of Nurbs
