The g131 doesn't work unless you have the g05.1 on. We turn on 1604 bit 0 so it is on automatically. Then just worry about g131. The r values still work. With P M and f there are three separate tables to get the looked ahead parameters from so you could customize them. But they're pretty much all the same from the factory. I believe our machine came with two NC formats and one of them was a standard five axis with no TWP or G 43.4

My suggestion would be to helix interpolate your corners then do your finish passes, or do your it in two depth cuts with a spring at each level. I agree that tool deflection is likely the culprit. That is a way bendy tool. You are at 5xØ if you were to bury the tool up to the flutes, but in reality you are probably at close to 6xØ. I am guessing .850 stickout? You would likely be good if you were at 3xØ or less. As Ron mentioned, take an indicator and check the wall deflection. I would expect on a straight portion with a spring pass you probably have .001" or so. Once the engagement goes up as it will in the corner, you will have much much more. By my math assuming 45 degree helix, you have a pretty even split of 3 and 4 points of contact in cut when you go through the corners. In a straight wall situation, you still have a mixture of 3 and 4 contact points, but more on the 3 side. With less depth of cut you would be in the 1 to 2 contact point, not ideal, might chatter, but won't deflect nearly as much (less than half). All that said, there is also no reason you should not max out your spindle speed to 12000, you could also probably double your chip load and still be conservative. 12k @ 50ipm should be good for a new starting place. Reduce feeds by 50% in the corners. With increase in speeds and feeds you should get it done in the same amount of time. With that machine you should be able to hold very tight tolerances at 50ipm. Much tighter than you are likely seeing for cutter deflection.

The problem is due to having no default printer. http://kb.mastercam.com/KnowledgebaseArticle50620.aspx Problem When launching Mastercam, an error dialog pops up saying Failed to Initialize COM. Cause Mastercam was unable to initialize a Windows system that is used to interact with some Windows components. Solution Go into the Windows Control Panel, Devices and Printers, and right-click on the Microsoft XPS Document Writer. Select Set as default printer. Mastercam should now launch with the XPS writer as the default printer

I use Mastercam, I create a fast WCS and the a boundry box and then top it off with 3 dim to get what I need. this take just a few mins really less then 5 min to do. Or use the Verisurfs Tools Minium Bounding box and it will create a WCS for you.

Too much load on that tool. Take a spring pass in the corner using the same speeds and feeds and your part will come into tolerance. All tools move and that tool is deflecting. Want to test my call take a .00005" indicator and run it up and down the corner and see the taper you're getting from top to bottom. I watched a 1/4 ball endmill deflect to almost 30 degrees one time and not break. I was machining a locate slot on a 40 ton turbine housing about 25 years ago on a HBM. 3 other people had tried all of them with 20+ years experience and they all failed. The slot was 6" deep and had to have a .001 tolerance from top to bottom. I took the 2" diameter 6 flute endmill and worked on it for 6 hours. I had 4 different indicators setup to control back lash. I took 12 cuts in the same place and all 12 cuts removed material. It wasn't until the 12 cut that I got the doblocks to go from top to bottom on that shape. Why was that? Tool deflection. The .0065 of material for 1/2" of of material is a lot of material to remove for a finish pass. Try getting a 7 flute endmill and take the same cut the difference will be night and day. Lets teach you some Physics about tools. The cross section of 3 flute tool is about 45-50% of the tool diameter. That means your tool effective strength ratio to length of cut is at 50% of the tool diameter. Your working with .08 diam of tool to fight against push back from the material as it is cutting. Now you have .0065 of material and that is about 8.5% of the effective tool diameter fighting against you to do this with. Now move to a 7 flute tool and you have about 70-75% off the tool diameter to work with. You have a much stronger tool due to the core being a bigger diameter. People always think you must use a 3 flute tool when finishing aluminum. No you don't have to use a 3 flute tool to finish aluminum. I will use a uncoated 5-7 flute tool in aluminum all day long with superior results to a 3 flute tool. Problem is finding them uncoated. Problem is the aluminum will stick to any tool costed with an aluminum substrate and that is the bigger issue doing it than the tool loading up for finishing.