Variable Radius Wrapper

[richardandtracyParticipant @richardandtracy]

Does anyone know of one?

[richardandtracyParticipant @richardandtracy]

I have a question:

Does anyone know of a variable radius toolpath wrapper program?

I want to engrave the surface of some pens and have realised that the standard wrapper type program that assumes a fixed work radius is quite a serious limitation the decoration that can be applied to the pens. Does anyone know of a program where a profile can be entered and also the un-wrapped toolpath so the two can be combined to make a generalised wrapper for parts with both cylindrical and non-cylindrical sections?

I have been thinking about how I would do it myself, and the programming would be far from easy – making a cylindrical wrapper seem quite simple in comparison.

Regards,

Richard

Edited By richardandtracy on 25/11/2013 10:25:59

[jason udallParticipant @jasonudall57142]

I was about to refeer you to a thread here but since you started that one.. I guess you are aware..btw the interpolation..does it attempt to deal with compound curves?

[richardandtracyParticipant @richardandtracy]

Jason,

The wrapper program I wrote does cope with compound curves provided it is a Z component to an XY plane arc, I have a feeling it wouldn't be too difficult to make it work with XZ and YZ plane arcs. In fact, I'm not entirely sure why I didn't incorporate XZ & YZ plane arcs – possibly because CNCWrapper only works in the XY plane and I wasn't thinking things through, probably was as simple as that.

It doesn't, though, make it easy to have a variable radius work. Imagine something like a sphere, and you wish to machine angled slots to a constant depth on the surface of that sphere. With the current wrapper idea you'd need to incorporate the changing radius of the sphere in the input file Z axis. It would be nicer to have a reference profile and the input file to be on the flat, where it is much easier to think about, draw and create the toolpath code. Then the variable radius wrapper puts in all the A axis stuff as well as all the Z components necessary to cope with the varying work diameter.

Regards,

Richard

 

Edited By richardandtracy on 25/11/2013 11:58:34

[David JuppParticipant @davidjupp51506]

Some CAM programs allow you to project text onto the (non-flat / non-uniform) surface of an object, and they will then work out tool-paths.

Wrapping and projecting are different, so this may not be what you want – or it may be close enough…

[richardandtracyParticipant @richardandtracy]

Projecting would be close enough. The projected path could then be wrapped.

Can I ask, what packages (preferably free!) can do this?

Regards,

Richard

[blowlampParticipant @blowlamp]

CamBam will do that. Just import an STL surface and you can project text and curves onto it. Then use an Engrave operation to generate the toolpaths.

Martin.

[richardandtracyParticipant @richardandtracy]

Thanks Martin. I shall investigate that – it sounds like a good option.

Regards,

Richard.

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

Finite element approach , zones – each individually simple , transforms , Jacobians .

Coordinate system appropriate to task – especially cylindrical and spherical .

Much in common with map projections .

Two cases :

Flat plan – has to be distorted to fit complex curved shape .

Plan in largely numerical form which cannot be drawn on paper – need not be distorted to fit complex curved shape .

[richardandtracyParticipant @richardandtracy]

Michael, I am trying to make life easy for myself, not make a lifetime's work in getting to the point where I can start machining…

When pen making, which is what I want to do, the deviation from a constant radius cylinder is not usually huge, so shrinking the engraving to fit a taper won't have a serious effect on the design and won't look too bad. It will, however. look very unusual.

Regards,

Richard

[jason udallParticipant @jasonudall57142]

Mm don’t people do something like that on wine glasses ?…may be take a google of “eggbot”..

[blowlampParticipant @blowlamp]

A way to project the text onto a surface in CAD and transfer it to CAM. **LINK**

Martin.

[richardandtracyParticipant @richardandtracy]

Interesting CAD package, Martin. Which one was it? I don't recognise it. Have played with AutoCAD/DraftSight & SolidWorks, but no others.

Regards,

Richard

[blowlampParticipant @blowlamp]

It's MoI. See here

Martin.

[richardandtracyParticipant @richardandtracy]

Thanks Martin, you've given me 2 avenues to explore now, much appreciated.

Regards,

Richard

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