How to create carvings with CNC

Hi,

I know this is probably the wrong forum but...

I have just obtained a second-hand SainSmart 3018 pro CNC. They have some example Gcode files, one of which is a bas-relief dragon.

When I run the Gcode the router moves back and forth like an old CRT TV scanning and cuts the carving one line at a time.

I am trying to find out what this method is called so I can google it. It seems to be like V-Carving but that seems to be more like making carvings as if they are done with a V chisel.

I would ultimately like to be able to take an STL and convert it to this style of Gcode, preferably for free.

I used FreeCad and have played with Blender.

Raster scan. Mach 3 has some capability to carve from various image formats, though I've never tried it.

Alternatively a CAM package like CamBam (highly recommended) can import image files and probably generate g-code from them.

Most half decent CAM programs will do it, that is just a 3D parallel cut which is best used as a finish pass after first roughting out particularly if it's deep relief. You say you have a stl file then the machine does not know if it's a block of metal or dragon, it just looks at the surface and you set the tool to cut that.

It is not always the best option as it won't give such a fine finish on vertical surfaces as it does those with more horizontal but there are other paths that the tool can be set to use that will take care of those. F360 has several options

Edited By JasonB on 15/07/2022 13:42:28

This was a simulation I did for someone, just relief carving but doing it on 4 axis to build up a complete shape, just used and STEP file and basic 3D adaptive and could then have followed up with a finer finish option if doing it for real.

Edited By JasonB on 15/07/2022 14:03:55

Have a look at the Vetric software

**LINK**

regards Martin

DeskProto is designed for this sort of work.

It has quite a few strategies to help optimise its toolpaths. There is also free version available, but with limitations.

Martin.

Thanks, as a complete novice it is quite a steep learning curve. The DeskProto looks promising, the free version seems to do what I want. No doubt as I get more into it I will need other features but I need to crawl before I can walk.

Hi Adrian, the world of cnc is a bit of a minefield for the hobbyist. However there are a lot of good quality videos on utube covering all the aspects of cnc. I use vcurve for the router which is very easy to use, and there is a good forum and video support. However there are some free cad software available but I am not sure of the support available. Also there are a few cnc hobby forums on Facebook that you may find useful.

One of the members (name forgotten) here has a web site (search Chesnut Pens) . There you will find downloads for converting photos into lithophanes and a few more interesting bits and pieces.

As I said the G-code is the easy bit, creating of finding an image may be more difficult.

This is a Dragon I found on Grabcad in the form of a solidworks file which I downloaded, opened and then saved as a STEP file in Alibre. From there the STEP file was opened in F360 and a simple parallel 3D cut selected, I went with a rather coarse finish to give the idea in reality you would want to take more passes closer together for better resoultion but that's just a case of entering a couple of different numbers. F360 spits out the G-code all 47000 lines of it in a few seconds and simulates the results as shown in this screen capture. Best watched on youtube at full screen size

Edited By JasonB on 15/07/2022 20:47:42

Jason thanks for that, maybe I will have to have a look at F360.

You saying "parallel 3D cut" gave me another google phrase so I have now found a plugin for Blender that will do it too.

I have a brass Donald Duck key hanger, I have already tried photogrammetry on it, but ultimately I want to scale it up and carve it in wood. I also have a really nice Greenman STL that I would like to do.

I had a look earlier and there is a free addon for F360 which will take a photo and convert it to a 3D surface, you then just treat it like any other 3D object to machine