Hi Gene, I just set up a sim config with the same axis vel / accel limits, and ran your code at 200% feed override in G64 P0:
http://imagebin.ca/v/2JdzAY0jhjp4 http://imagebin.ca/v/2JdylG3HDyLx It looks like the culprit is a combination of the 200% maximum feed override and the comparatively low maximum acceleration of your X / Y axes. You can see in the halscope plot that the peak acceleration is about 6.8 in / sec^2, which is ~86% of your maximum axis acceleration of 7.8 in / sec^2. The trajectory planner is designed only to use about that much of the maximum acceleration for cornering, so that there is some left over to accelerate / decelerate along the path. In your case, you can do a few things to fix it: 1. Add a blend tolerance (consider an explicit Q < P, something like G64 P0.002 Q0.001) 2. Decrease maximum feed override 3. Increase axis max accelerations 4. Add fillets on your corners and use a smaller mill As you've already found, (1) is probably the best solution, especially since you're doing hand-coded programs. -Rob On Mon, Oct 19, 2015 at 8:16 PM, Gene Heskett <[email protected]> wrote: > On Monday 19 October 2015 19:48:31 Robert Ellenberg wrote: > > > Depending on your machine's acceleration, and the feed you requested, > > that could be correct default behavior. The default blend tolerance is > > unlimited. Given the speed limitations the TP used to have, it may not > > have been able to go fast enough to need a big blend like that, so you > > might not have seen it before. Does it still happen at lower feeds? > > > I didn't notice any such effect when a cousin of that code was running on > my toy mill about a year ago. > > > Another possible cause is a large maximum feed override, which causes > > the TP to take larger blends. For example, a maximum feed override of > > 200% means that at any time, the TP is prepared to go 2x your > > requested feed, and doing so safely means a larger corner radius, even > > if your requested feed isn't that fast. > > > Hummm, my feed override is larger than any axis, Z in particular, can > move at. These are things I an still "fine tuning" as I bring this > machine online to make parts. > > Recommendations? > > > In general, I would always recommend using an explicit tolerance for > > blending. > > > > Can you share a code snippet that leads to this behavior (also a > > config file so I can see your max acceleration / velocity)? > > Finger-bores.ngc attached. Remove the G64 line to see it in whats > supposed to be a square cutout for a decorative ebony button. > > And GO704fast.ini is attached also, > > Thanks for looking, Rob, its appreciated. > > > Rob > > > > On Mon, Oct 19, 2015, 7:33 PM Gene Heskett <[email protected]> wrote: > > > Greetings all; > > > > > > I was just forced to add a G64 P0.001 to my code for making the > > > screw shank, a circular cut just deep enough to absorb the screw > > > head, topped by a square cutout with 1/16" radius corners as left by > > > a 1/8" mill run in a square pattern. Without it, that square pocket > > > was turned into a 1 corner pointed circle! > > > > > > That sure seems like way too aggressive path blending to me. I also > > > noted that turning the alpha-blend checkbox on and off, had zero > > > effect on the cut result. The initial white backplot trace was > > > perfect, but not the wooden result when the code was executed, it > > > was hugely, completely unusably bad. > > > > > > This is 2.7.0, updated Saturday IIRC. > > > > > > Is that the expected result? > > Cheers, Gene Heskett > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > ------------------------------------------------------------------------------ > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > > ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
