bimmersix

Ok, so here are the two differences I can spot now between S3D and Cura: S3D uses relative extruder coordinates on each layer, and; S3D uses G1 moves, but Cura uses G0 and G1. However - both Cura files, with and without Coast enabled, use the G0 moves but no coast doesn't make the noise. Cura + Coast and print/coast speeds being equal, as you suggested, extruder still clicks/bangs like it is trying to rapidly accelerate and can't. I'm beyond my ability to interpret gcode, so maybe something will stand out to you. I also know the speeds are not identical - tried to get them close but have sliced so many test files of this I am starting to lose track. By the way, I have not experienced this slicing with Rep Host, slic3r, or Mattercontrol, although those don't have a coast option, but otherwise this behavior is anomalous. Cura + Coast (a few layers in): ;LAYER:3 G0 X54.211 Y-4.4 Z0.9 G0 X45.27 Y4.73 G0 X45.2 Y4.8 ;TYPE:WALL-OUTER G1 F1800 X45.2 Y-4.8 E141.29238 G1 X54.8 Y-4.8 E141.60627 G1 X54.8 Y4.8 E141.92016 G1 X45.825 Y4.8 E142.21362 G0 X45.2 Y4.8 G0 F15000 X45.2 Y4.6 G0 X45.379 Y4.401 ;TYPE:SKIN G1 F3000 E142.23406 G1 F1200 X54.4 Y-4.62 E142.6512 G0 X54.47 Y-4.69 G0 F15000 X54.619 Y-4.273 S3D + Coast, same place, same layer, although paths are slightly different: G1 X45.720 Y4.280 F9000 G1 E0.0000 F3000 G92 E0 G1 X45.720 Y-4.280 E0.3416 F1800 G1 X54.280 Y-4.280 E0.6833 G1 X54.280 Y4.280 E1.0249 G1 X46.020 Y4.280 E1.3546 G1 X45.720 Y4.280 F1800 ; outer perimeter G1 X45.240 Y4.760 F9000 G92 E0 G1 X45.240 Y-4.760 E0.3800 F1200 G1 X54.760 Y-4.760 E0.7599 G1 X54.760 Y4.760 E1.1399 G1 X45.540 Y4.760 E1.5079 G1 X45.240 Y4.760 F1200 ; solid layer G1 X46.638 Y3.872 F9000

You are correct, it is a set of 10mm cubes. The firmware is the latest Repetier (0.92, I believe) and I've been using Rep since that is what originally came with my Rostock a year ago, when I knew nothing of other firmwares. I will slice in S3D and submit for comparison. Regarding Marlin and the differing speeds - I actually sliced this with Cura keeping the "Coast Speed" at 100%, keeping the last move at the same speed, but it exhibited the exact same symptom. I can increase the speed for your test, but the reason it was slow was just because it was the first layer. I normally print at 40 mm/sec and travel at 250 mm/sec, being a delta. I can change the travel speed and reslice. I'm also happy to reslice with faster print speeds for the first layer, but the symptom does persist even when moving to the full print speeds. Again, I appreciate the time you have put into this.

Thanks so much for the fast response. I watched the gcode carefully and confirmed it is at the "moment" that the issue happens. I had the same thought about feedrates and accel. The extruder works fine at 80 mm/sec on retracts, which is the max firmware setting for it, and I turned the acceleration way down from the defaults with no effect on the sound. This gcode is all from Cura. I don't see anything weird, so I'm not sure what to make of it, but that is why I'm asking the experts. Excerpt from retraction cube print, coast enabled: ;TYPE:WALL-OUTER G1 F3000 E25.68521 G1 F900 X-4.8 Y4.8 E26.15605 G1 X-4.8 Y-4.8 E26.62689 G1 X4.8 Y-4.8 E27.09773 G1 X4.8 Y4.385 E27.54821 G0 F720 X4.8 Y4.8 <----------This is the coast move G0 F5625 X4.6 Y4.8 G0 X4.619 Y4.619 ;TYPE:SKIN G1 F3000 E27.56857 G1 F900 X-4.619 Y-4.619 E28.20933 G0 X-4.689 Y-4.689 G0 F5625 X-4.053 Y-4.619 G1 F900 X4.619 Y4.053 E28.81083 G0 X4.689 Y4.123 G0 F5625 X4.619 Y3.488 G1 F900 X-3.488 Y-4.619 E29.37314 G0 X-3.558 Y-4.689 Same place, no coast: ;TYPE:WALL-OUTER G1 F3000 E25.68521 G1 F900 X-4.8 Y4.8 E26.15605 G1 X-4.8 Y-4.8 E26.62689 G1 X4.8 Y-4.8 E27.09773 G1 X4.8 Y4.8 E27.56857 G0 F5625 X4.6 Y4.8 G0 X4.619 Y4.619 ;TYPE:SKIN G1 F900 X-4.619 Y-4.619 E28.20933 G0 X-4.689 Y-4.689 G0 F5625 X-4.053 Y-4.619 G1 F900 X4.619 Y4.053 E28.81083 G0 X4.689 Y4.123 G0 F5625 X4.619 Y3.488 G1 F900 X-3.488 Y-4.619 E29.37314 G0 X-3.558 Y-4.689

Let me start by thanking the Ultimaker team for creating a really nice slicer package and making it available for even non-Ultimaker owners. Also, big thanks for adding Delta support back in 2.4 beta. I recently installed Cura 2.3.1 and the Cura 2.4 beta and I'm really impressed with them. 2.4 actually fixed one of the two issues I was having (3rd party printers connecting reliably not withstanding). I have a Rostock Max v2 with a Prometheus hotend, 0.4mm, and a 5.18/1 geared extruder. It works very nicely and creates great prints, EXCEPT with stringing because retraction on a long bowden setup is tricky. Because of this, I was really interested in the Coast feature in Cura and S3D. Coast completely fixed my stringing issues. However, Coast in Cura causes a strange symptom - every time the print gets to a "coast" spot, the extruder clicks loudly but doesn't move (and it isn't supposed to move), almost like it is being told to accelerate very quickly and doesn't have the power to do so. This happens frequently, but is completely absent in prints with Coast off but with all of the same settings otherwise. Coast in S3D does not cause this. Does anyone have suggestions? Tonight, I can run the gcode for a small print with and without Coast and upload for comparison. I've spent a bit of time trying to figure this out but have reached the end of my abilities. -Joel in Phoenix