sheetcam.com

Running the simulation for the sample "knob" program and there's something gone wrong. The tool doesn't appear to be taking cuts out from stock and the tool is "cutting" (like cutting) from the centerish point of the stock upwards. Looks like something to do with the post processing - which I haven't configured.

Troy

The maths involved in offsetting arcs and calculating arc intersections gets really ugly and prone to errors. It is far simpler and more reliable to break the arcs into a series of line segments and work with those. That also allows me to use fixed point calculations which work around the annoying edge case rounding issues you get with floating point numbers. SheetCam's milling/routing code uses floating point and even after 15+ years working on it, it is still possible to catch the code out with certain very specific geometry.

Most CAM packages break up arcs like this. For example in Fusion you see an 'accuracy' option in a lot of operations. Among other things it controls how many line segments arcs are broken into. They then rebuild the arcs when it is time to post process. I have not yet had the time to write that part of the code. Currently the accuracy is fixed at 1 micron (0.00004") which is plenty for all but the most high end specialist machines.

I can't replicate your issue here. Could you load the job then create a support file (Help->create a support file) and send it to me.

Hi Troy,

I found the problem. Go to Options->machine and set the machine type to lathe. As you are in milling/routing mode the axes are in the wrong place. It took me a while to figure out what it was doing!

I killed a motor on my lathe :/

now on half term break will play next week and feedback

Yes Les, that was it - one checkbox (duh). But, WOW... I'm seriously gobsmacked at the work you've put into this. I've only run the sim so far, but it's obvious this is a major project. Hats off mate!
Okay, now I have to make some swarf with this tool.

Troy

Les, so am I correct in gathering there's currently no boring/internal work option yet? Apologies if this is yet another thing I failed to read in the thread [blush].

I like the way the turning tools are configured. It's quite different to what I'm used to (selecting or drawing the complete tool & insert), but it looks reasonably practical for my purposes.

Troy

Okay, another dumb question (I think there might be a few of these): how do I define the stock?

Thanks,

Troy

I'm working on boring and face contouring. After that comes drilling and threading. I'd also like to add an option to tool definition where you can simply enter the standard tool tip and holder codes and SheetCam does the rest.

To define the stock go to Options->job options->material.

The problem is, when I try and define the stock that way, it's configured for a flat sheet ie. asks for sheet thickness not stock diameter? Yes the machine is definitely configured for turning now.

Troy

Thickness, rapid clearance and height of the bottom of the material are not used by turning. I'll hide them for the next release. The size and origin options should allow you to define the diameter and length, as well as the origin position.

So when I go to material options I get this window:
https://www.propulsionlabs.com.au/material_options.png

Troy

Huh. That's odd. I wonder if it is a layout problem. Try resizing the window.

Cool, that fixed it. As soon as I moved the resize, it was instantly as it should be.

Cheers,

Troy

Another thing to add to the 'to be fixed list'...

Les,
So I configure a round stock of 20mm diameter x 100mm long. I draw a line in dxf from 0,0 to -10,-10, import the dxf; however the geometry I just imported is showing up on the left side of the stock whereas I would've expected it to show up on the right side? It should at least default to the right side.

Troy