So I know to aim for 1 thou chipload when machining. Don’t make dust, right?
What about a finishing pass and/or spring pass? Are these exceptions? Is it permissible to take these really light cuts to get a nice surface finish in aluminum? Or should I be doing more math, and how do I figure out what kind of “stock to leave” number I should aim for?
My guideline for stock to leave is it should be greater than the largest defect/deflection/deviation one is seeing when making the roughing pass.
Based on that dimension one can determine if multiple passes are feasible, and if so, what thickness they should be, and based on the width of material being removed, what sort of chipload should be workable.
or just make dust for the finishing pass…
it is what I end up with normally, since usually I do both a smaller stepover and a very shallow depth for these… (say 0.2mm depth at 25% to 33% stepover)
small stepover + shallow depth give me a nicer finish, and that’s the point of the finishing pass for me
Usually I’ll rough with both axial and radial stock to leave then perform finishing toolpaths to the flat areas with radial stock to leave that matches the roughing. Then come in and ramp down wall and leave a very small amount of axial stock so that it doesn’t mess with the floor finish. Really depends on many things and tolerances as well. You can ramp a bit more aggressively on the finish pass but IMO its not worth saving seconds, 1-2 degrees works well and is very reliable.
For the most consistent finish cuts, you’ll want to minimize load spikes.
oh yeah, chipload
Don’t worry a whole bunch about chipload on finishing passes, just keep it reasonable
above 0.0005ish is a good rule of thumb. Reason is, you aren’t creating a bunch of heat during finishing so chipload isn’t make or break like roughing. Tool load is more important imo