I am drip feeding my machine at 9600 baud, so when I am 3D surfacing, the thousands of tiny line segments cause data starvation and the machine to stutter and give jerky motion. 9600 is the max baud rate and the program is too big to fit in the control, so nothing I can do there. I am doing curved surfaces and using surface finish parallel to make two passes at 90 degrees to each other to put a 'crosshatch' type surface finish on the part. Problem is that the part is oriented straight, so the two surface finish parallel operations are at -45 degrees and +45 degrees - in other words, they are not in the XZ or YZ plane. I cannot figure out how to get MasterCAM to output 3D arcs. Is it possible? There is an "output 3D arc entry motion" checkbox on the Arc Filter/Tolerance page, but it's grayed out. I have the boxes checked for XY/XZ/YZ, but I see nothing else for 3D arcs. I have the In my control definition, under the "arc/mill" tab, "all planes supported" is checked under the Helix Support section, and I have all the boxes checked for XY/XZ/YZ at the top. I don't see anything else in this section of the Control Definition that would allow 3D arcs. Am I missing something, or is this just not something I can do? Any help would be appreciated... I am essentially machining a half-egg shape, and the surfacing is the bulk of the code size, so if I can get MCam to output arcs, my code would shrink massively. Thanks! Mark

I don't think MasterCAM has "figured out" that intermediate stock, I *KNOW* they have. That is the only way they could have generated the STL file. The fact that they have chosen to represent that information to the user in STL format and the fact that the software lacks the capability to subtract an STL from a solid isn't a limitation of what I am trying to do, it's a limitation of the software. There's nothing preventing the software from doing some sort of averaging of the triangles to generate a planar surface or warning the user that a shape generated from this method lacks accuracy, but it's not a technological limitation in terms of something that cannot be done in the realm of possibility. It's just that MasterCAM can't do it. I don't require an easy way to do it - just to know whether it can be done within this software or whether I need to process some models in other software. I can certainly get the job done with what I have on hand. It just means I have to use more capable software to do it. I was hoping to do it right within MasterCAM, but I realize the software is exceptionally limited, especially when it comes to any sort of drawing - so I wasn't expecting much - and wasn't disappointed!

It's not simply an issue of the solid model being more or less accurate than the STL file of the machined verified stock, it's also the fact that the part file from the customer is a finished part but as the part goes through the multiple steps of machining, it will transition from raw material to that finished part - and I will want to mount it in a vacuum fixture at some intermediate point at which it will not have all the features of the finished part. That means I am modeling features which do not exist for no reason other than to use them to create my vacuum fixture - and there's no reason I ought to have to do that, when MasterCAM has already figured out what that intermediate stock will look like. It exists both in the form of the stock model as well as an STL file exportable from the verification tool. It seems like MasterCAM simply lacks the power and capability to use the stock model as a reference for any sort of modeling, and also lacks the power and capability to use STL files for the same. I can't say I am surprised, but I was hoping I was wrong.

I use almost exclusively vacuum fixtures for small one-off parts that are made of specialized materials, and often these parts have reasonably complex 3D surfaces. I generally machine the first side from a solid block, then flip it over and machine the second side while the first side is held in a vacuum fixture that is a negative image of the first machined side. I would like to be able to take the first side machined surface and (in MasterCAM), flip that over and use it as a cutting tool on an extruded block to create the vacuum fixture. I know I can use the original solid model, but this is often less accurate than using the actual machined result. I am already using the Stock Model feature, so what's an easy way to do this? I can't seem to use the stock model to actually do anything. I have also tried exporting the verify results as an STL file and importing that, but I can't use it either with the impression tool or as a boolean cutting surface on an extrude, so I am not sure how to make this work. Any tips? It seems like there must be a much easier way to achieve this.