adze_cnc wrote:I don't think I have ever used a ball-end bit to rough out a 3D project. It must just wail like a banshee.
Also, while you say you were leaving "0.04" behind you never (at least I can't recall seeing it) mentioned the 1/4" bit's pass depth.
Why would a ball nose bit be bad for roughing out its a 3D (2.5 D) in a dish and no it did not make any noise, why would it? Sure It might be faster to use a typical 2 flute standard one. Once again the .04 was something I never entered... It was there and I assumed it was set by the software when I selected the .250 bit in the 2.5D toolpath creation. I have Never set a roughing material in any of these 2.5 projects and they have all worked fine?
So Copy and Pasted right from the VCP9.5 online documentation on Finishing Tool Path: Clicking the Select button opens the Tool Database from which the required tool can be selected.Clicking the Edit button opens the Edit Tool form which allows the cutting parameters for the selected tool to be modified, without changing the master information in the database. ADDED I posted the screen shot above it has NO edit tool form
For most 3D Finishing cuts a Ball Nosed end mill is used with a reasonably small stepover (8 - 12% of the tool diameter is typical).Variations on this tool type such as a tapered Ball Nosed cutter will also work and may offer more strength with smaller tool sizes.The size of tool will depend on the size of the part and the detail within the 3D part.Use the preview function to check the finish quality and detail; if they are not to a high enough standard then the job may require smaller tooling or a smaller stepover.3D cutting is always a tradeoff between time and quality and an optimum balance of tool size, finish quality, and time to cut.The choices made will always depend on an individual's personal preferences or the specifications of the job.
Roughing Copy & Paste Not One word about setting only that its calculated:
Machining AllowanceThe machining allowance is a virtual thickness which is added to the 3D model when the Roughing Toolpath is calculated. This ensures that the toolpath leaves some extra material on the roughed part.
This is beneficial for two main reasons, the first is that when roughing it tends to be done with relatively large tool and aggressive cuts and so is more prone (depending on the material) to chip, this skin helps to prevent the chipping affect the finished surface.The second reason is that most tools cut well when they are constantly removing material.Therefore leaving an allowance of material on ensures that there is always at least some material for the finishing toolpath to remove