3D milling problem

[mattpatt]

Hi All,

Have a bit of an issue with a part I'm making. Not sure about attaching files and what have you so I'll try to explain.

Part designed etc in SW 2007, and using Solid Cam 11.1 for toolpaths.

The single part is rotated, then both parts copied across in X, for a total of 6 parts, This is how they'll be machined.

I've got most of the toolpaths done, but each part has three 8mm wide slots, 8mm deep, with a 4mm radius at the bottom of the slot. So in cross section the slot is "U" shaped.

I've set up the 3D roughing and everything seems to work fine, using a 6mm ball nose, with 0.2mm surface offset. I then used the same operation parameters, and tool to finish the job (constant z). Although it gets the job done, it doesn't do it how I want. The tool comes down, takes a small cut, retracts to the start level, jumps across to another slot, takes a smal cut, then rapids back to the first slot and finishes it off. I can't figure out why it's doing it. Running the sold verify simulation shows that the finished job is correct, but I'm confused as to why it's not finishing one slot at a time.

I've just finished one job, which is actually a very similar part, with the same slots, and the toolpaths don't jump around like this! It simply goes in and finishes one slot, then moves to the next slot.

All the various parameters are the same between the two jobs so I can't suss why it's doing it. Any ideas?

What's the best thing I can do as far as letting you guys see the part? Attach SW file or....?

I would like to start the job tomorrow, but I'm not happy about this bit.

If I can attach the SW file I also have some questions about the best way of approaching the initial roughing out of the job. I've got one set of toolpaths, but I'm pretty sure they're not optimum.

Anyway, thanks in advance if you can give me any help.

[Brakeman Bob]

Have a look in the "data" dialog for Constant Z machining. There is and option in there for what I call waterline cutting which is exactly the behavior you describe - I think it is called "complete Z level". This strategy is used when you are leaving very thin walls as you machine down. Also have a look in the Z entry dialog and select the "angle between paths" option with a entry angle of 5°. This will give a very neat tool path for finishing.

[mattpatt]

Thanks Brakeman Bob. I'll have a look at those options.

I got past the problem for now by using some seperate operations and then transforming the operations using the translate/matrix option. I've decided to use this option quite aggressively in the parts I'm doing now and I'm very pleased with the outcome. Much smaller program, and works very nicely.

Finished the first batch at 2am and I'm rather happy with the results.