Denford Software & Machines

Recent question from a customer:

Firstly I need the dimensions in the drawing to be the final dimensions of the machined article. So far I have only been able to get the cutter to follow the line of the drawing, making the final article too small
Secondly I would like the machine to make multiple passes during the cutting operation, getting progressively smaller until it reaches the final dimensions to achieve the best surface finish possible, what would be the bet way of doing this?

The first thing I notice, is that the DXF file contains multiple lines/arcs on top of each other.

These additional ones should be deleted, to avoid confusion later on....

The shape needs to be closed, in order for tool offset plans, or offset paths to be created

Join the ends of the shape together with two new lines, as shown. Then select all, and press J to join the lines and arcs into one shape / path...

It would be possible to now go to the CAM wizard, and create an offset path, according to the selected tool diameter.

Because you want to implement varying offset cuts, then it may be easier to create the offset paths within the CAD part, and simply use the Follow machining plan.

You will need to know the diameter of the tool you intend to use.

Select the newly joined shape, and create offset paths of different amounts (remember to enter the Radius of the tool as the final offset path required)

Now, create any additional offsets in the same way, so that you can create rough cuts, then a final finish cut that is not removing much material...

You should now be ready to create the G and M code program

Goto the CAM wizard and create multiple FOLLOW plans.

If you create one plan, and select all the offset paths created, then you cannot guarantee which order the paths will be machined.
Createing seperate plans for each path, gives you full control over the machining order - the plan at the top of the list will be machined first, then the next, etc....