In VectorArt 3D Machinist why do we get significantly different toolpaths on rough vs finish even if all settings are the same?
Example:
1) take a design such as Warrior50105V_B.V3M
2) Scale it to 36"x36" and adjust material thickness
Test A
3) skip the roughing pass
4) Specify a 0.75" ballnose, 0.75" pass depth, 8% stepover for the finish pass
5) note the estimated machine time and the toolpath
Test B
3) for the roughing pass specify a 0.75" ballnose, 0.75" pass depth, 8% stepover
4) note the estimated machine time and the toolpath
Different results on Roughing vs Finish pass
Moderator: Todd Bailey
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BrianM
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I don't have the model you refer to, but the roughing pass will make multiple passes depending on the stepdown of the tool.
The finish pass will always be a single pass over the model (the stepdown is ignored, as a finishing toolpath always assumes that any roughing that is needed has been carried out).
Is the 0.75" stepdown large enough to ensure the roughing only does one pass?
Brian
The finish pass will always be a single pass over the model (the stepdown is ignored, as a finishing toolpath always assumes that any roughing that is needed has been carried out).
Is the 0.75" stepdown large enough to ensure the roughing only does one pass?
Brian
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Rcnewcomb
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Brian,
Thanks for the response. After studying this I did notice that finish ignores stepdown.
In the case of the design I'm modeling, it has a max depth of over 2 inches so multiple passes might be required. We are also playing with some tooling strategies that look at using more of the side-cutting of the long ballnose bit for roughing, i.e. deep passes but small stepovers.
FYI, I've also noticed that sometimes I can find the "sweet spot" of finishing and roughing where suddenly the total machine time drops dramatically, but it seems to be dependent on a combination of model size and tooling parameters. We had one design that went from 8 hours of machine time to 2 hours, but change the bits or stepovers one way or the other and it shot back up to 8 hours.
I'm sure in a future release (V273.5) you'll run a bit of calculus to determine the optimum bit sizes, geometries, and settings based on model size, material, and machine capabilities which will give the best results in the shortest amount of machine time.
Another feature that I'd like is to do a final-final pass that does a cleanup around the design by looking for major Z changes and follows the profile of the design.
Thanks for the response. After studying this I did notice that finish ignores stepdown.
In the case of the design I'm modeling, it has a max depth of over 2 inches so multiple passes might be required. We are also playing with some tooling strategies that look at using more of the side-cutting of the long ballnose bit for roughing, i.e. deep passes but small stepovers.
FYI, I've also noticed that sometimes I can find the "sweet spot" of finishing and roughing where suddenly the total machine time drops dramatically, but it seems to be dependent on a combination of model size and tooling parameters. We had one design that went from 8 hours of machine time to 2 hours, but change the bits or stepovers one way or the other and it shot back up to 8 hours.
I'm sure in a future release (V273.5) you'll run a bit of calculus to determine the optimum bit sizes, geometries, and settings based on model size, material, and machine capabilities which will give the best results in the shortest amount of machine time.
Another feature that I'd like is to do a final-final pass that does a cleanup around the design by looking for major Z changes and follows the profile of the design.