Any Gurus On Mastercam? Problem Creating A Tool Path

Basically I have a part that is about 1.5in Dia with 6, .160" dia pins sticking up so I need to machine around everything to leave just the pins sticking up. radius for the circle of 6 pins is .5in and I am wanting to run about all the pins with a .375 cutter. I want to cut full depth (.250") by leading into one side and stay in the part running around these pins until done, then lead out.

I have tried about everything in MC from contour paths to surface paths, nothing seems to get even close and I cannot keep the tool down or just cannot generate the paths at all. I am not sure if there is a surfacing path that would be best for this or if I am on the right track with contours. I am getting a bunch of retracts to go to the next pin, and plunges in the wrong spot which I cannot alter. Any ideas would be appreciated. I do not have too many obstacles on the part other than the pins. I do want to use Ccomp so running in the same rotation would probably be best.

From what I understand, you need to do perhaps a 7.5 dia circle with the others as islands but I have found if you have a lot of parts to run you might as well program it out your sself as the pocketing seems to take way too many unneeded passes everywhere except where you need them.

Am I understanding you correctly that you want to cut around all the pins first, so they are well supported as they are cut, then cut the rest of the material away? I do this all the time with carbon EDM electrodes, using MasterCAM v9.

I use a pocket routine, selecting all the islands and the outer boundary (if the tool won't fit between the islands and the outer boundary, draw a new, larger outer boundary). Then, turn the roughing passes OFF. If you don't want to plunge adjacent to the posts, select LEAD IN LEAD OUT and add short arcs. Someplace there is a check box for KEEP TOOL DOWN, but it my be faster to let it retract and plunge. Using the pocket toolpath rather than the contour toolpath will ensure that none of the lead ins hit the other features; contour doesn't in v9.

I then copy this operation a second time (or just select the geometry again) and add some clearance in MATERIAL TO LEAVE X Y so the cutter doesn't rub your previously cut posts, turn on the roughing routine and select the style. Depending on the roughing style, I'll either turn off the FINISH routine (works well with spiral and morph spiral toolpaths) or leave it on to pick up any bits left standing by a zig zag roughing pass. The XY clearance you specify will keep the finish pass that far away from the posts, but also that far way from the outline of the part, so you may need to draw a slightly larger circle and use that for the outer boundary of the pocket.

Dennis

Every time I have tried to create a pocket path, it says there is an invalid arc #8 pocket standard, and fails ot at least will not backplot. it creates the path folder but no paths. I am at a loss to figure out why. Would I select the top of the pins to machine around, the cylinders of the pins, or the face that would be Z zero for the operation? My concern of selecting the lower face is it might try to contain the tool path within the boundaries of the part profile and that surely will not work right. The tool must travel outside that boundary.

Viper, it sounds like there are some problems with your geometry, or the way you're selecting it.

To eliminate those problems, just draw your 1.5 circle, and your six smaller circles. No 3D geometry needed.

Xform Offset the 1.5 circle out by 60-70% of your cutter diameter. Start a pocket toolpath, and select the extra large circle, and the 6 smaller circles you just drew. Go to the pocket parameters page, and uncheck the "Finish Outer Boundary" box, then check the "Keep Tool Down" and "Machine finish passes after roughing all pockets" box.

I just did this in X3 to make sure it would do what you need, and that took me less time than typing this response.

[FONT=&quot]I'm a couple releases behind, but I've found two things that will yield an operation with no toolpaths:

Forgetting to pick a chain that becomes the boundary that makes all the other chains islands;

Or specifying a tool that's too large to fit between the islands and the boundary, WHEN ALL THE FINISH PASS OFFSETS are included.

The solution to the first is to draw additional geometry that becomes the boundary, in this case the circle that Joe is offsetting outward.

An indication of the second problem is to turn FINISH OUTER BOUNDARY on, which will force the tool to cut as much of the outer boundary as It can, dodging around the islands. If this isn't acceptable, the moving the outer boundary outward normally sets things right.

Dennis[/FONT]

I created some simple geometry in MC like you indicated and had the same errors (invalid arc). I must be doing something wrong when creating my pocket path. I am selecting the top of the circles from 3D and 2D and making sure they all have the same rotation. If you must define an outer boundary, how is this created? Could this be the problem? It asks if I want to indicate the problem area but nothing lights up so I still have no idea on that.

Modelman said:

[FONT=&quot]I'm a couple releases behind, but I've found two things that will yield an operation with no toolpaths:

Forgetting to pick a chain that becomes the boundary that makes all the other chains islands;

Or specifying a tool that's too large to fit between the islands and the boundary, WHEN ALL THE FINISH PASS OFFSETS are included.

The solution to the first is to draw additional geometry that becomes the boundary, in this case the circle that Joe is offsetting outward.

An indication of the second problem is to turn FINISH OUTER BOUNDARY on, which will force the tool to cut as much of the outer boundary as It can, dodging around the islands. If this isn't acceptable, the moving the outer boundary outward normally sets things right.

Dennis[/FONT]

Click to expand...

I really think a lot of my issues are from a lack of experience with the pocket path. This will actually be the first time using it. No, have not selected any containment geometry. If I were to select the outer profile of the part, it would not work right. I will try to get a pic of the part in question. I have found no way to create a bounding box or containment chain for the cutter. All I have selected is the 6 pin circles on the top of them. Seems my inexperience is getting me here!

Yeah, there's definitely something going on. You need to pick the extra large circle so that the tool knows where it's outer boundary is, since it's a pocket routine. MC will know which circles are the islands and which is the boundary.

DO NOT pick the 1.5 circle.

I really appreciate your help! I created an outer circle for containment I guess and it finally produced the right path!!! I really thought there was another selector for the containment area. I will try to apply this to the part when I run back over to the shop after lunch.


MUCH appreciated!

[FONT=&quot]I'm going to defer to Joe here, as I know that MC has changed the Operations Manager interface since the version I'm running, and so I can't give very specific instructions. But, If you just pick the six circles, it is trying to cut six pockets, but can't because the tool is too large. You can prove this to yourself by changing the tool selection to a 1/8" EM, and MC will then toolpath six pockets. You need that outer boundary, whether it's part of the part geometry, or additional geometry you draw, BEFORE YOU GO INTO the Operations Manager, or whatever they call it now.

I normally create a new layer (whoops, I mean level, I also draw in AutoCAD and their layers there) for this sort of construction, naming it to somehow relate to the toolpaths I'm creating. Since in my work I may have several different toolpaths all generated over the same geometry that is the total shape I'm creating electrodes for, I end up with a whole series of levels that contain tool boundaries, points that are the origin of the different electrodes, and often times chains that define the features I'm cutting, so I can turn the level with the total geometry off to eliminate the clutter.

Try what Joe suggested; draw simple 2-D geometry over the features you need to toolpath on a separate layer, then turn the base drawing level when picking the geometry to toolpath.

Dennis[/FONT]