Calculating 3D finishing toolpaths really slow!

[llrjt]

Hi Guys,

I'm a new FeatureCAM user and very impressed by the 2.5D milling features and ease of use. I'm just starting to look at 3D milling for mould tool making and I'm experiencing extreme slowness in calculating 3D finishing passes and would like to check whether others are experiencing the same problem.

I'm using FeatureCAM 13.1.0.40, the latest version from the website, and running on a 3.4GHz PC with 1.5GB of RAM. Calculation of Z roughing tool paths with a 12mm ball nose cutter and 1mm stepover takes about 30 seconds. When I add a final 3D spiral finishing pass with a small 1.5mm (0.05") diameter ball nose cutter with stepover of about 0.025mm (1 ten thousandth ") calculation times goes up to about half an hour. Is this normal?! It makes trying out different strategies almost impossible.

If it is normal, then presumably I need to alter my workflow, so this is the final calculation.

I would be very grateful if anyone could share their experiences.

Richard

[Skillet]

That is normal. If you just want to see the simulation, you should increase the stepover. Then when you want to post, change it back to what you really want. Also, it is usually faster if you do the wireframe sim first.

Skillet

[llrjt]

Thanks for confirming that this is normal. Do you just restrict yourself to a comparison between the model and machined surfaces at the end to make sure that you've got rid of the material you need?

You can see the part I'm trying to machine at http://www.livelearning.com/public/shell.jpg - its the cavity for a mould.

It looks like Z roughing and then 3D spiral finishing with a small stepover will sort out the main surfaces. Would you bother pencil milling all the small fillets like the ones at the bottom of the four pillars at the deeper end? Would you simply add a 2.5D strategy for milling the hexgaon shaped nut features on the tops of the pillars?

When I was experimenting with selecting just the fillet surfaces around the base of the four pillars I found that the toolpaths went through the surfaces and this problem was not corrected when I set the adjacent surfaces as boundaries. Do you have any idea what I might have been doing wrong?

If there is any chance you could look at my .fm file, create toolpaths and send it back for me to look at, I would be very grateful as this is my first 3D part.

Thanks again,
Richard

[Skillet]

Send the file to: shop@phy.olemiss.edu
I'll see what I can do with it.

Skillet