DeskProto user forum

Manually creating freeform boundaries with the spline tools is a little fiddly and easily unprecise.
It would be super helpful if one could just click on (sur)faces of the part to define precise boundaries within which a specific toolpath strategy should be applied.

Optimally this selection would be based on the surfaces of the original CAD design, not tessellated STL triangles.

If meshing the STEP files within Deskproto is considered too difficult then perhaps there could be an option to select both an STL and a STEP file when loading 3D geometry?
All translation/rotation operations would then be applied to both. And the STEP file would mainly be used as an additional option to define boundaries. (After clicking on the surfaces vector boundaries could automatically be generated and then handed over to the existing code that copes with vector boundaries, so the new feature would be more an addition, less a change).

That feature would imho be tremendously helpful!

That would indeed be a nice addition.
Alternatively, you could load the border from a vector file (dxf/svg/...).

Exporting a DXF or SVG from a 3D cad design from the right perspectives, getting the placement and scaling right etc. would also be tedious and potentially error prone extra steps. Being able to just click on the related surface should be the fastest approach in many (most) cases. And when not, the existing alternative ways to create vectors would still exist.

The suggestion by MaFu will indeed be a good workaround: use your CAD program to create a curve around the surface that you need (in top view), export that as DXF and then import it in DeskProto as boundary for the freeform area.

Implementing STEP import is a major issue, requiring a lot of programming effort (also when using an existing library). So do not expect such addition very soon, sorry.

I had not yet seen your 16:47 post.
When you export the STL and the DXF from the same CAD model, scaling and alignment in DeskProto should be automatic.

Thanks, for the feedback. In most cad software exporting a DXF from a 3D design usually means one first has to derive a drawing, add a projection of the 3D object to this drawing, place and scale it on the worksheet etc. (As these drawings are usually meant for documentation, they are not 1:1 usually)
It might work as a workaround but doesn't appear like a good default workflow.
But will experiment with this!

Ok, tried it out now. First I opened the part in Alibre Design, derived a drawing, inserted the front view as 1:1 frame and saved the result as DXF.
When loading that in the freeform view of Deskproto it only loads the frame with the drawing name but not the actual projection.
So I loaded the DXF in Affinity Designer, deleted the frame and saved the result as SVG.>
Was able to load the vectors in Deskproto now. Neither the size nor the position is right though, so it has to be resized and moved manually to approximately fit.

This workflow is better than trying to draw the face contour manually with a spline but also not very convenient either.

Indeed not a convenient workflow...

I guess I have been lucky: in the CAD software that I use (Rhino) this works smoothly. In Rhino I displayed a top view of this 3D test geometry, selected the cylinder, generated a 'Silhouette' curve and exported that as DXF.
When opening DXF and STL in DeskProto they match automatically. I simply thought that this would be standard in 3D CAD programs.

Your request for Step import is on the wish list, however as said that is a long list.

Thanks for considering!
I guess many people would appreciate STEP import and surface-based work-area selection!

And having STEP import could also open the door for many new things in the further future. Currently we can already increase the resolution of the paths (along the path), but that doesn't help when the STL file is too low poly. Outputting an STL file that captures all details down to the resolution limit of the CNC (e.g. 0.1mm) could become really large. But a STEP file combined with an appropriately small path step size could indeed use the full resolution of the machine without changing the principle approach!

Good to hear that you have a long list, looking forward to all the cool things that await us! :) (And fingers crossed this isn't a FIFO list ;) )

Re machine resolution: 0.1mm would still be coarse - I mean realistically more 0.01mm or less. Thus, large STL file!