Curved surface script

[GeoffreyGRoy]

Dear tsikows

What you see in the image are the cutting paths - not the finished surface.  If fact the lines show the paths of the bottom centre of the 0.25" tool.  Near the stock surface the tool needs to move vertically downwards until the outer edge reaches the stock surface, then it follows a path, not exactly circular, as the edge of the tool follows the required surface profile.  You can see the effect of this by making the tool diameter quite small - as it approaches  zero the path will get closer to the finished surface.

Hope this helps,

Geoff

[EddyCurrent]

You could also use the "Side Profile" method.

I've attached a simple cb file showing the idea.

[dh42]

Hello

I just used the plugin to do a circular print like this to help a guy on a French forum:



First I used a sharp edge between the 2 polyline section of the path but the result is missing toolpath on the external side of the curve ; if I add a radius to the path, I get a better result ... but not a sharp edge as on the 3D.



So I tried to move the path on a side of the profile arc instead of centered .. and I get my sharp edge with a path with no arc. But ... the behavior is not exactly what I expected  The result is shifted to one side of the Path polyline .. not a big problem of course, I can move the resulting path, but my common sense expected that the result was aligned on the profile ... maybe a setting that I don't know ? (I tried a polyline/invert on the profile poly, but with the same result)



It is really a nice plugin that you did here Geoff !!

The post on the French forum

https://www.usinages.com/threads/cambam-et-profilage-3d.175640/#post-2221634

++
David

[EddyCurrent]

David,

I think the Rail Sweep ( Sweep2 ) plugin would also have worked.

[dh42]

Hello

I'll have a try ...

++
David

[GeoffreyGRoy]

I have been looking again at my Curved Surface plugin (CSP)  to see what might be possible.  Essentially I have found what David has described.  The path for the extrusion cannot have sharp kinks.  The if the paths with two straight lines as described by David are joined with a short fillet, and then by choosing a suitable small diameter cutter then it is possible to get close to the required sharp edge - but it will still be filleted.

I suspect, also, that if you try to break the machining into two parts you will get some over-cutting near the outer-side corner, or some uncut regions depending on where you align the two parts.  You might be able to tweak an acceptable result.

Taking another approach however, it might be possible to use the Profile-Side Profile option - assuming that the profile to be cut is (semi)circular, like as shown in the attached image.  In this case I have created two edges to be profiled as two polylines aligning them with the top ends of the required semi-circular profile.  Then I defined a profile MOP on each with a concave edge profile (only final cuts displayed in the image.)  I think that you will get a relatively sharp edge on the outer corner, but the inner corner will be filleted towards the bottom of the profile - though quite sharp near the surface.

Geoff

[dh42]

Hello Geoff

I tried the "side profile" but I get almost the same problem that with "Waterline - Finish", the bottom of the curved surface is not cut and that leave a "pick" at the bottom.

++
David

[dh42]

David,

I think the Rail Sweep ( Sweep2 ) plugin would also have worked.

I just have a look ... and no, this plugin is designed to generate the 3D surface itself, not toolptahs (I already have the 3D surface)

++
David