Curve 5 Axis - backplot / verify clearance display issues..

[djstedman]

Ok so I am using a curve 5 axis toolpath with depth cuts to rough in a slot around two thirds of the outside diameter of a part using a 4th axis.

 

I am experiencing issues in backplot and verify which I have attached a picture below to help illustrate.

 

So essentially the desired behavior is to take multiple depth cuts and between each cut move out to a clearance height.

 

Based on the code that I am getting its pretty much doing this.. move z minus, rotate in cut, retract to z plus clearance, rotate back to next cut, and repeat.. this is exactly what I wanted to happen .. so that's great.. love it.

 

Now the issue.. so in verify and in backplot what is happening is that when it makes the rotation back to position for the next cut.. instead of maintaining Z position at the clearance position.. it APPEARS to move straight through the part to the clearance position. Because of this it appears to cut right through the diameter and gouge.. though in fact the actual code doesn't do this.

 

I have run into this before and just got around it at the time by making a much bigger clearance position so it wouldn't do this in verify .. but I am wondering if this is something anyone knows how to fix.. cause it has me stumped.. short of verifying all my code by evaluation in a code editor I'm at a loss..

 

Any suggestions?

[djstedman]

Well in case it helps anyone, using reference points for approach and retract seems to have made it so at least I can backplot and verify without it appearing to gouge.. however the code it produces wont work.. so I guess for backplot and verify I turn that on .. and for posting turn it off.. ugly .. but at least it will let me see how the path will actually cut ..

[maestro]

Is this on a table/table config machine? If so, Mastercam doesn't do a very good job of showing the actual motion on the machine. In your example, if this is on say a Haas trunnion, the tool will reach the end of the cut, retract out, the part will rotate back to the start with little or no movement of the tool, and start the next cut. A Head on head machine may do just what backplot and verify show. Using gcode verification software such as Vericut is the best way to see just what the machine motion will be. I have had times when Mcam shows a collision such as yours and not collide on the machin, as well as not show a collision and have one on the machine. Again, Vericut can be your best friend in these situations.

[djstedman]

yeah Vericut would be great.. actual NC validation built for the actual machine .. however the powers that be need to be convinced of that for it to happen.. and that is easier said than done.

 

I have tried to convince them multiple times to no avail.. so will just have to watch the code and take care things don't go bad..

[Chipmakr]

Define a cylindrical safety zone in your x axis slightly larger than the largest Ø you are cutting. This method gives me code that will backplot, verify, & post correctly.

[gcode]

Turn on the rotatry axis simulation in the backplot settings

[Chris Rizzo]

If you use machine sim, (which is well worth it) on the post page at the bottom is rapid rate move. Uncheck the move increment .1 and it should work. I use that for a horizontal and it solves the artificial collisions.