agree strongly .. certain toolpath software seems to love cutting arcs .. and struggles with splines - breaking them down into a zillion little straight cuts

>>Would this be possible?

I think so. Today I experimented with a procedure that I think will work well creating a collection of arcs for any given 2d or 3d spline. See QT movie below:

http://www.csi-concepts.com/Demo/vc/SplineToArcs.mov

Tim - that looks perfect. Are there user-definable parameters/options? I know you probably can't answer this, but any clue about development timeline - will these new tools be implemented as a point upgrade, or will we have to wait for V5? (and if the latter, do you have a rough idea of a release date?) I could really use the view manipulation changes immediately.

Thanks again.

Addendum: would this kind of conversion algorithm make possible the conversion of a series of straight line segments into a series of matching tangent arcs? I do a lot of tracing over of "curves" from SketchUp, and automating this process would be AWESOME - and a huge selling point for SU users.

Tim,

This is a great feature!

I've wanted this for a long time now so that I could convert illustrator artwork into arcs for use on a waterjet (and I even talked to a software engineer at Solidworks about this in January; they cant' do it.). Many of these older 2 axis controls aren't able to process point to point motions rapidly, so small incremental moves to simulate splines kill productivity.

GibbsCAM has this feature, but it is always hit or miss with the spline formats that it will work well with. The conversion parameter that they use is a minimum radius, and I think that is enough.

tom

Jol,

If it was me, I would have a single tool that would:

a) convert to arc (minimum radius parameter and/or slider for feedback)
b) offset curve (offset parameter, inside/outside button)
c) add centerpoint to arcs (y/n button; good for hand programming G code)
d) export (y/n button, default format, default folder)

This makes it easy to import the converted curve to another application by just importing from the default folder. You still need to deal with the G codes or equivalent, but the centerpoints might be helpful.

I used to use the offset and arc centerpoints with dimensioning to hand program G code prior to getting GibbsCAM. It wasn't too bad for simple stuff, but more features meant for complexity. No reason that can't be done as is with CU.

tom

>>Just a question - would this functionality be better placed in ..
>>.. Edit>change object type

Yes, I think you are right.

Exactly. SketchUp's arcs, circles, and curves are actually facetted entities. When they are exported, they come across as series of straight lines. This can produce files with enormous numbers of entities, which CNC machines gag on. I spend a lot of time tracing these collections of straight lines into actual arcs; automating the process would save TONS of time, and, therefore, shekels.

The other day I sent a dxf file to a company that does laser cutting.
The program that is used to provide code for the laser cutter choked on a
simple spline. The laser cutter program needs lines and arcs, not splines. It also had errors with basic circles and radii. Can we have a Change object command feature soon please? It seems to be a very basic feature in this line of work and would be greatly appreciated. It is too bad we can't simply point the finger at the other poor software developers and tell them to modernize something that already "just works" so that us designer types don't have to futtz with all these simple geometry and file format translation issues.

I don't expect any solutions, but some added insight to my next sub-comment would be appreciated.
It seems that there is a lack of communication between the CAD industry and the makers of machines that add & remove material in the real world. Or is it that the solutions that are available are just too expensive for the typical job shop businesses? I suppose it could just be a general resistance to change or a risk in disrupting daily workflow? It is complicated, I am sure.