On Monday 19 October 2015 21:59:36 Robert Ellenberg wrote: > 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
I've tried to stay conservative to prevent stepper stalls. But with my z home switch to close to the mechanical up limit, I have that cranked to where its not hitting the top of the post slot, but the stop at that search speed is best described as brutal even at that low a search velocity. So I don't think I can go much higher on the Z, but the XY can probably go up. I'll see what happens if I double the accels for X & Y. Probably tomorrow. That code miss-fired this evening, but I've got that sorted now and its working well enough that I made up a sample joint in white pine & it will do very well once the screws are pulled up that go in those holes. > 4. Add fillets on your corners and use a smaller mill That, because of the holes depth, doesn't feel like a workable option. I already have a pallet made to hold both sizes of the ebony buttons, and fine tuning that square cutout shouldn't be more than a thou for a good glue it in fit. That would take a var per axis if my buttons are off a square to a rectangle. I've since found and fixed a loosened x ball nut mounting in the toy mill that took its 2 thou of backlash out to around 9, so I have a ready made bag of buttons that are not square by a few thou. I have more ebony, but at the price, I'll mill that pocket to fit what I have made up, and adjust the pocket size when I have to make more. Or even shrink it 5 thou sand these to fit. I've a smallish disk sander thats still too fast. > As you've already found, (1) is probably the best solution, especially > since you're doing hand-coded programs. I don't have an CAM sw other than pcb-gcode. So this is all out of my ancient head. Keeps me out of the bars & all that. :) True, but production speed is also a factor. As it is right now, a finished 1x12 board end is around 20 minutes of spindle & vacuum on time. I have 3 more of these things to make, one for each of my surviving 4 sons. So thats times 24, then about half that for the base frame parts. Finishing is the real time killer though. Thats a coat of somewhat thinned minwax gloss poly, (with a coat of shellac on the end grain to seal it & sand them smooth so it doesn't slurp up the poly and turn quite dark) wiped on 2x a day for 10 days or more. Thanks Robert. 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
