Good morning everyone, I have a question about the fusion 360 openbuilds post processor. When I export a file with small radii, the machine starts stuttering quite a bit. Larger circles and moves are going fine, but it is just the really small moves that are really stuttery. Any idea what the solution could be?
How small? please upload the file. also, how big is your tool? Arcs that have radius smaller than the bit radius will be linearized if the default setting has not been changed. Linearization can result in many very small line segments but that is unlikely since the default settings work perfectly for most people, so the question is what is peculiar about your small arcs? Turning off linearization will almost guarrantee an error 33 so that is not a solution. Fusion does have default settings that cause very small leadin and leadout arcs that can be a problem but since they are normally vertical they are linearized anyway. It is possible that your controller settings are contributing, have you changed any GRBL defaults?
This is the fusion 360 file the inner circkle, and other small 'crevaces' are causing some problems. I am using a 6mm ball nose endmill. As far as I know my settings are not very different from the default, but i will try to reset them and see if it gets any better.
well, the 1x setup shows lots of little curls along the edges of the dimples, yet the 4x setup does not, so you need to compare the 4x setup to the 1x setup and see what settings are different that cause those little curls to disappear (a good thing) and apply that to all setups. those curls are usually the source of error 33, being small arcs (and they waste time too) despite these odd little curls the 1x file I just generated ran with success. I will try the 4x setup....
Thanks for responding! The 4x setup is the one I have been using, the weird curls were caused by too small of a stepover. I ran the 4x setup on a piece of wood today, and it behaved quite weird, like it was still doing the little arcs. I attached a video in which you can see the stuttering I meant. Could it be that one of my GRBL settings on my openbuilds blackbox isn't right? Tank you so much for taking the time and effort for helping!!
There are a couple nonstandard ones: You have $1=35, the default is $1=25, we recommend $1=255 to keep motors locked $26=25, the default is $26=250, could cause limits issues $31=3500, the default is $31=0 - this setting changes the scale (not doing what you think its doing - its not preventing spindle from running under 3500rpm, that should be set on the VFDs Min Freq parameters. As its its causing an offset that makes spindle run slower than commanded) $120-122 - your acceleration is set lower than our standard LEAD1515 profile OpenBuilds-CONTROL/grbl-settings-defaults.js at master · OpenBuilds/OpenBuilds-CONTROL and this is already very conservative - ideally one wants to tune it to be faster See Grbl v1.1 Configuration · gnea/grbl Wiki $120-122 settings may affect the issue you experienced
That’s a good point, didn’t realize that, thank you! I will look into that tomorrow, would be so awesome if that’s the problem
also $11=0.010 ; Junction deviation, millimeters default is 0.02 please please don't change these specific defaults (junction deviation and arc tolerance), they are not really user tuneable values, the GRBL internals have been tuned to work with the defaults and changing them NEVER makes it better (-:
strange, was sure my Uno had the default on it, just burned it last week from a fresh copy of GRBL 1.1g oh, I see what happened, I flashed from Arduino IDE then loaded a profile from OBControl, and most of those machines have 0.02 as the default Minimill is 0.01 Lead and Sphinx are 0.02 as are others i have looked at
I am happy to report that my machine is working correctly indeed after changing the settings you recommended! Thank you sooo much, me and my customers are very happy and grateful !!
