How to draw the design to cut with a plasma machine

[J.Salapuig]

Hi, I am doing some designs using corel or solid works to put them into my cutting software. The problem is when I have drawn using spline lines ( like a rounded curve using vectors to choose with detail each rounded form to every cm of the line, like if I draw a letter "S" ). When I have drawn it and saved it in .DXF, when I put it into de cutting software I can se small united lines in every curve, so it isn't a regular curve, and when I put at the machine to cut it, it cuttes like small bites which mkes that the cut is not polished.

Should I use another tool to draw? or there is a tool to convert these lines into other tipe?
Thanks!

 

[WorkshopChris]

How do the lines look in software when you zoom in? you may need to add more points to the splines to smooth out bends. Looks like the dxf outline may be a series of small arc's.

 

[slim_boy_fat]

If it's to be a 'one-off' design, could you use something like a Powerfile to smooth the 'jagged' edges?

 

[MattH]

Does the cutting software support arc's? Looks like it doesn't.

 

[gerrymoore]

I use serif drawplus 8, sheetcam, and Mach3 and get perfect results every time...a lot of my work I hand draw in using a tablet.

 

[julianf]

I don't know your software, but in AutoCAD there used to be a function to explode text. This changed it from a font to a vector shape for export. This may, or may not, be something to look at.

A bodge-fix would be to change the constant velocity settings (assuming mach) to force smoothing. This can, however have unwanted results.

 

[gerrymoore]

Yes......I forgot that sometimes you have to 'convert text to curves'...depends on the software as Julian says...it sounds like you are trying to 'draw' text rather than using available fonts?

 

[MattH]

He's created curves in Vector format in Corel and exported to DXF so that is not the issue.

The problem will be with the toolpath generation which is going to be down to the postprocessor in use (i.e. not using the Mach3 Arc's PP) or something similar.

 

[graffian]

How do the lines look in software when you zoom in? you may need to add more points to the splines to smooth out bends. Looks like the dxf outline may be a series of small arc's.

Less points worked best for me. I was drawing text for a vinyl cutter, no suitable font so I drew it.
I merged end points and drew shapes with the minimum number of nodes to get the lines smooth;
I got excellent results, that was with Illustrator.

 

[WorkshopChris]

OK i haven't played with Illustrator for a few years, interesting results.
I can see how less nodes gives a smoother line, definitely good. Might have to download a trial copy and have a look, How does that work when you have a profile to copy, i have found to match a small radius i have had to zoom in till maybe a 12mm radius fills the screen and manually add additional nodes to keep it all smooth and to the correct profile.
It might depend how accurately you need to match a existing shape.
I just wish adobe run a licence you could just pay and use by the hour, its good software but it might only get used a few times a year.

 

[graffian]

I have copied some really small letting, well really small for the vinyl cutter, sub 2mm height.
You control the radius by pulling little bars around, pull them out and you get a big rad.
I zoom in and out as needed. I did try tracing the lettering, scanning the trace and putting the
scan on a layer and tracing over it, but in the end I worked much quicker just making the font's
up as I went, I admit I did check them against the scan and I had them within my pencil lines.
If you use font's you can turn them into paths and outlines. Corel draw should be just as good
as illustrator.

Iis you drawing full of nodes, if the little cuts are from a node to node you need to use less
nodes, if they are not from node to node it doesn't sound like your drawing is at fault.