2.5D pocketing rapid problem

[mayhugh1]

Dave,
I created a rectangular contour and place several closed contours inside. I selected the 2.5D pocketing operation. Then I set the z-heights of the closed contours as well as the outermost contour. I let the workpiece default to the dimensions of the outer contour an ran the simluation. The simulation ran as expected with no errors and so I posted the code and set up to actually cut the part. The size of the workpiece for the actual milling operation was exactly the same size of the assumed workpiece. Early into the operation the machine broke the cutter. Investigating, it looks to me that the posted code created a rapid move into the workpiece which caught the cutter and caused to spin in the collet and dive into the workpiece. Should Sprutcam not have allowed a rapid into the workpiece or, in this type of project, am I supposed to define additional stock on the workpiece for protection during approaches/plunges? Dave, in case the answer isn't obvious, I am emailing you the project and the g-code. The problem started in the first 7170 line number when the rapid was set to 24 ipm with the tool breakage happening within the next 3 lines or so. The workpiece is 3.5" in the x direction and 1.75" in the y direction. Theorigin is set at x0,y0.

Thanks,
Terry

[S4 Monster]

Hi Terry,

I've taken a look at the CNC code and I cannot see anything wrong. I presume that you are calling the F24 a rapid move? A rapid move would normally be denoted by a G0.
The F24 feed value is calculated by SprutCAM using the 'Return feed' option. This is applied when SprutCAM is doing a move that is not cutting but approaching the next cut.
On this part it is doing this (as far as I can tell) outside of the workpiece, which is correct.



On the move that you highlighted, the F24 move is outside of the workpiece and the next arc move uses F8 which is cutting the part.



I am not familiar with the control that you are using. Does it apply the Feedrate value on the line of code that it is written or on the following line? If it does it on the following line (unlikely) then this could be the cause.

Yes you could make the workpiece bigger which would ensure that the cutter is clear of the actual workpiece although this shouldn't be required oif the workpiece is exactly to size.
You could also adjust the 'Return feed' amount.
You could also use the outer curve as a restriction and prevent the cutter moving outside of the workpiece.

I am testing build 1.28 which seems to solve some of the imperial value problems that were there in build 1.25. Contact your SprutCAM supplier to obtain an update.

Dave

[mayhugh1]

Thanks Dave. The whole thing was my own dumb problem. The workpiece was not perfectly square after all and in the corner where the crash occurred the tool hit overhanging material. I think the collet was not torqued sufficiently and this cause the tool to dig into the workpiece and break. I re-ran the job this evening and it turned out perfectly. Sorry to have wasted your time. - Terry

[S4 Monster]

Hi Terry, I'm just glad you managed to solve it and that you're confidence is restored in SprutCAM.
It's all part of the learning process, and when everything is new to you (machine/software/process) it can be very difficult to track down the cause of a fault, I know this because I've been there many times myself

Dave