Relief carving small detailed parts - V-carving from greyscale image

[ALAN2525]

I want to be able to engrave a 3D relief object in acrylic and need some advice regarding making the 2d artwork to generate the toolpaths.

I'm after something like this:



Hopefully the image will speak 1000 words. The black parts need to be machined to a depth of approx 2 or 3 mm with the white parts standing out (i.e. the surface of the plastic without any material removed.

I also have a physical object I'd like to make a copy of.

The parts will be very small - approx 25mm square and I'd need to use a small a tool as possible to get any of the small detail, could some kind of vee point carving tool be used for this and the passes taken very close.

The second question regarding making a copy of an actual physical part. I think it could be scanned using a touch probe, but I have no clue what i'd do with the resultant information.

Ideally I'd like to try to work with an existing design and see what settings would work for my own machine.

Does anyone have a greyscale file for a relief carving - something like the image above that would work as a test.

[Stepper Monkey]

[IMG][/IMG]
I created this 3d model straight from your greyscale with no modification. I use this technique almost exclusively now - although I have a dedicated touch probe scanner, I haven't touched it in years.
If I were you I would simply take a photo of the objects you wish to reproduce and photoshop it to an 8-bit greyscale. Increase of decrease the contrast to adjust relief depth. Once you get the hang of it, I find it is much easier, faster, and cleaner than trying to modify and clean up 3d scanner images.

The second image here is a toolpath of this relief done at 25mm, using a 15 degree vee point tool - showing that as you suspected it indeed would work very well. With a .09 mm wide tip, you can see that quite a bit of detail comes out with excellent surface finish - cutting another pass at 90 degrees to the first would give a nearly perfect surface and avoid the possibility of any "linen" lines from the curved surfaces at all.

[beone]

Stepper Monkey,
What did you use to create the 3d model?
Dave

[Stepper Monkey]

There are a couple of ways to do the same thing, but for that one I just used ArtCam. ArtCam has a neat trick - if you import an image as a greyscale, it can automatically set black as the lowest Z point and white as the highest Z point. Just give a range to Z, and instant finished model. I didn't need to manipulate that particular image or resulting model, that was the result from just simply loading it into the program. Other times it can be more involved, but not usually by too much.
Even in simple 8-bit greyscale that gives you 256 different Z height steps.
Now you know why I don't mess with 3d touch probe stuff much anymore.
There are other programs that will do the same thing as well, I just don't have the experience with them to make a comparison between them.

[thkoutsidthebox]

Photo V Carve will do the same thing, but I haven't used it myself so can't say if it works well or not. Scroll to the bottom of the page to see it.
http://www.vectric.com/WebSite/Vectr...c_features.htm

[ALAN2525]

Thanks Stepper Monkey!

Those images look great - I think I'll forget about the touch probe and try to play around with some high quality digital camera images instead.

Artcam looks interesting too

[thkoutsidthebox]

.

[ALAN2525]

I was just looking for a demo for artcam, is the software you used Artcam Insignia?

I'd like to try the software with my macnhine and wanted to make sure I've downloaded the correct demo!

Thanks,

Alan

[Tony Mac]

Hi Alan,

You can machine this type of grayscale image relief using PhotoVCarve as thkoutsidthebox suggested. A Trial version can be downloaded from the Vectric web site along with tutorials and getting started documents. The Trial version will also let you cut the evaluation files on your own CNC machine. This Trial version will show you exactly what the picture / image will look when machined.

See > www.vectric.com



A note of caution - it's quite difficult to make typical photo's work well using this method of machining. The software products all work in the same way, making white regions the highest points and black the lowest with various levels of grey being scaled between the two extremes.

Drawing / Designing grayscale images to make them work for 3D machining also requires considerable skill with software such as PhotoShop, but it is certainly possible.

Machining pictures with very shallow Z depth will often give good results.

I hope this helps,

Tony Mac

[ALAN2525]

That software looks useful, at the moment I'm using Rolands 3D engrave and Virtual Modela but the simulation isn't that good at seeing what the finish is like.

I'm a little stuck at the actual 2d graphics part too.

Whats the best way of generating the actual greyscale image? I'm applying various gausian blurs etc to the image to try to create the right kind of effect but it's very hit and miss.

[dcarr]

Originally Posted by ALAN2525 Whats the best way of generating the actual greyscale image? I'm applying various gausian blurs etc to the image to try to create the right kind of effect but it's very hit and miss.

Perhaps the best approach is to use a software program that allows sculpting on the surface - after conversion from image brightness to surface height, but before tool pathing. In VS3D, you can hammer, scrape, lift, smooth, etc. on selected regions of the surface to achieve the desired effect, all in real time while looking at a true 3D surface rather than a gray-scale image.
http://www.designscomputed.com/vs3d/...mg_emboss.html

[ALAN2525]

In Virtual Sculptor 3D (vs3d) will the software enable you to view a 3D view of the work rather than a 2d image that you can move the light over?

I'm just playing with the demo and it'd be great to be able to see the effects of hammer etc by looking at an isometric viewpoint of the model.