Poorman's roughing cut feature

[jepho]

@adrianre

It is probably quite a niche requirement for bas relief carving, but I have not been able to find free or open source software to generate GCODE from STL files that also will perform roughing cuts. I have several STL files that are deeper than my 1/8" V cutter can do.

I am not familiar with any free CAM software that will rough out a toolpath. this table here may point you in the right direction.

Software Table - LongMill CNC

I am also retired and I pay $18 per month for Carveco Maker, which has a roughing function. If you follow the video at the link…

First time using Ash

No worries. If it helps other folk to see a way forward, so much the better. As promised, here is the video clip concerning the carve shown above. It may help @Rstd2005 to get to grips with changing tools in a multi-tool carve, without a tool length measurement device. [3D Carving with Carveco Maker and gSender]

…and head along to around 10:29, you will see the roughing passes that Carveco Maker produces with a specific roughing toolpath.

@adrianre

I am wondering if this idea for a feature has any merit, the idea is to process the GCODE multiple times applying an incrementing depth limit. Then performing a final finish cut.

I don’t think this is how the roughing pass is achieved. The rough toolpath is offset from the finishing pass profile by an amount (maybe this is a fixed parameter?) and the .STL file also contains height information which is being read during the roughing and finishing toolpaths.

Measuring the finished profile and incrementing the depth would likely see the second pass cutting into the model because of the information for height and profile is not integrated. Without a 3D shape in space to follow, the movement in X and Y would be capable of 2.5D carving… if I understand your proposal correctly.

Could one draw an accurate profile around the area to be machined then have it repeat on many different layers, each with a separate toolpath. Yes, almost certainly. One issue with digital anything is that the discrete digital steps (unless you had a large number of steps in your descending passes) would make it unlikely to get smooth outlines.

I don’t know if any of this is helpful but as a Carveco Maker user, I have eliminated all of my 3D issues. I have used many varieties of software (both free and paid) and in the end decided that my time was far more valuable to me. I happily pay $18 per month (a few cups of coffee) and have no issues when processing 3D STL files.