Multi Axis Swarf Cutting Curved Profiles

[sam.jenkins]

We're using a 5 Axis Hurco VC500i.

I'm using the Swarf strategy for placing a chamfer around the edge of a part. I was expecting a nice smooth cutting motion (like the CAM simulation), but the machine was very jerky in the B and C axis.

Looking at the actual tool path, its made up of lots of small straight segments. I've played with the Feed Optimization  to try and slow the jerky movements but it doesn't help too much:

So a few questions:

1. Is it possible to generate the toolpath as an arc instead of segments?
2. If not, is there any way to synchronize the XY/BC feedrates axes to reduce the jerky movements?

[DarthBane55]

Hi, we did what you are doing a few times in the past, with acceptable results.

I see some yellow sections in your path, which means it is not completely smooth, it should be completely blue.  Also the tolerance has a huge effect on the result, the more points, the smoother it will be (less faceting).  But also, the smoothing codes of your machine has a huge effect as well.  For example, in our machines, the smoothing codes look like this:  G121R5  The R value can be 1 to 10, 10 being for a super accurate finish pass, but more jerky (as it hits each coordinate with extreme precision), and 1 being loose.

For 5-axis, it is better to set it to 1 "lose" and have a tight tolerance in the toolpath to generate a lot of points.  The reason as that with so many points, and a lose smoothing on the machine, the tool will "sail through the points" smoothly, instead of trying to hit each point exactly 100%, which would cause jerkyness.  But because there are so many points, the tool will never venture very far from them.  It will make a nice smooth curve through all the points.

I hope it makes sense...

Also, can you upload that file?  Maybe someone can have a look, but the yellow bits between the blue shouldn't be there.

[sam.jenkins]

Thanks for getting back to me with such a detailed response.

Just for clarity, the yellow sections are created when I enable 'feed optimization'. I did this to see if it would reduce the jerkyness (it didnt), but I left it in to help demonstarte the segmented toolpath. I should have mentioned this originally.

I will give your suggestions a go, and if its still jerky i'll upload some files.