{"action":"created","issue":{"url":"https://api.github.com/repos/prusa3d/Prusa-Firmware/issues/602","repository_url":"https://api.github.com/repos/prusa3d/Prusa-Firmware","labels_url":"https://api.github.com/repos/prusa3d/Prusa-Firmware/issues/602/labels{/name}","comments_url":"https://api.github.com/repos/prusa3d/Prusa-Firmware/issues/602/comments","events_url":"https://api.github.com/repos/prusa3d/Prusa-Firmware/issues/602/events","html_url":"https://github.com/prusa3d/Prusa-Firmware/issues/602","id":311711203,"number":602,"title":"Inconsistent Extrusion","user":{"login":"ff8jake","id":8582658,"avatar_url":"https://avatars3.githubusercontent.com/u/8582658?v=4","gravatar_id":"","url":"https://api.github.com/users/ff8jake","html_url":"https://github.com/ff8jake","followers_url":"https://api.github.com/users/ff8jake/followers","following_url":"https://api.github.com/users/ff8jake/following{/other_user}","gists_url":"https://api.github.com/users/ff8jake/gists{/gist_id}","starred_url":"https://api.github.com/users/ff8jake/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ff8jake/subscriptions","organizations_url":"https://api.github.com/users/ff8jake/orgs","repos_url":"https://api.github.com/users/ff8jake/repos","events_url":"https://api.github.com/users/ff8jake/events{/privacy}","received_events_url":"https://api.github.com/users/ff8jake/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":725,"created_at":"2018-04-05T17:59:31Z","updated_at":"2018-05-15T16:27:59Z","closed_at":null,"author_association":"NONE","body":"@XPila - Sorry for calling you out on this, just figured since you seem to be the one working on the linearity corrections and such you'd be the best in the know on this one.\r\n\r\nWe're seeing really inconsistent extrusion, beyond the moire effect that we were trying to fix with linearity correction. Do you know if they are related? I have tested a 40mm single wall cube with no infill, then cut it with scissors. Within a single wall on a single later, I have found my extrusion width getting wider/narrower (and only one extrusion command in the gcode for the entire wall). I also confirmed that where it becomes fatter happens on both the outside and the inside of the print, so this doesn't seem to be X/Y related.\r\n\r\nMany people on the forums are also seeing the same thing, here's some of the images. Looking at it straight on, the prints look fine and Z height seems to be fine. When you shine light down from above, the fatter lines cast shadows and it looks pretty rough.\r\n\r\n**EDIT: Please read before posting!**\r\n\r\nWe appreciate all the help everyone is adding to this post; however, many people are making suggestions without reading the megathread that is this issue. Here's what we _think_ we have squared away thus far. I will continue updating this as I read through the megathread again:\r\n\r\n**First and foremost, Prusa is seeing this on their in-house printers as well and have yet to find a fix. This isn't a simple \"tighten your belt\" issue.**\r\n\r\n1. This appears to be an extrusion issue. Bulges appear on both sides of a single wall print when they happen. We have many indications that this is the case and that **it is not belt or bearing related that we can tell**.\r\n2. This is happening on MK2, MK2S, MK2.5, and MK3. It is particularly bad on MK2.5 and MK3. https://github.com/prusa3d/Prusa-Firmware/issues/602#issuecomment-380480337 https://github.com/prusa3d/Prusa-Firmware/issues/602#issuecomment-387572449\r\n3. It is most visible when light is shining down from above the print. https://github.com/prusa3d/Prusa-Firmware/issues/602#issuecomment-379117854\r\n4. We've tried this without performing G80 mesh bed leveling with zero effect on results. Still curious on this one, as mesh bed leveling can't be effectively undefined in the firmware. https://github.com/prusa3d/Prusa-Firmware/issues/602#issuecomment-380804444\r\n5. Reverse bowden, while potentially helping prevent the random tug upward artifacts from spool binding, has no effect. Neither does completely loose filament. https://github.com/prusa3d/Prusa-Firmware/issues/602#issuecomment-381292126\r\n6. This doesn't appear to be caused by temperature fluctuations. Multiple users have attempted PID tuning and prints with bed off to rule out lack of current to the extruder. https://github.com/prusa3d/Prusa-Firmware/issues/602#issuecomment-381295862\r\n7. The MK3 uses a customized heatbreak, but users have swapped this out on multiple posts to no effect. https://github.com/prusa3d/Prusa-Firmware/issues/602#issuecomment-381413623\r\n8. This effect is present on a \"scratch built\" MK3, sharing only the Einsy, Heatbed, and Fans with a stock MK3.\r\n9. This effect is on both TMC2130 stepper drivers and whatever drivers are present in MK2.5.\r\n10. The effect is present on both Einsy and older Rambo. This is not TMC specific.\r\n11. Temperature being low _might_ cause some small pre-clog artifacts, but overall don't seem to be related to this issue. Just a common side effect of printing too cold?\r\n12. This happens on both Prusa firmware and official Marlin firmware.\r\n13. Small layer time extrusion issues were confusing the issue due to a Slic3r bug that has since been fixed.\r\n14. Bondtech has been replaced with a normal hobbed gear with pressure against a bearing, no change. https://github.com/prusa3d/Prusa-Firmware/issues/602#issuecomment-382079177\r\n15. To attempt to find if this was a firmware bug that was introduced since the MK2 firmware (before the problem was confirmed there, too), we tried extremely old/alpha MK3 firmware with zero effect. https://github.com/prusa3d/Prusa-Firmware/issues/602#issuecomment-382202968\r\n16. Power frequency seems to make no difference. https://github.com/prusa3d/Prusa-Firmware/issues/602#issuecomment-382391941\r\n17. Stepper currents have been adjusted high and low with minimal effect other than causing some people to miss steps.\r\n18. The fan on the heatbreak was changed to a higher volume setup without change, and Prusa confirms the volume of the Noctua should be sufficient to cool the heatbreak.\r\n19. A user had a wobbling bondtech gear. Several of us tested this after and found no indication that we had wobble yet we still have inconsistent extrusion. This appears to have been a one off issue someone was having and not across all MK3s.\r\n20. E-steps at 280 with 95% flow (the stock setting) appears to be the same as 266 e-steps. M502 was done to ensure old values weren't loaded from memory.\r\n21. **MANY MANY MANY** brands of filament have been tried. Yes, filament inconsistencies happen, but this is a very uniform bad extrusion quality. We've yet to find a MK3 that _doesn't_ have this problem.\r\n22. In case you don't want to accept the above, the same filaments were used in other printers and did not exhibit this effect across multiple test prints.\r\n23. This effect seems to be lessened by a bowden setup, likely acting as a filter, but it's still there.\r\n24. It seems geared steppers (or similar setups) mask this effect a bit, but we have very few samples to go off of.\r\n25. The effect happens even when bondtech gears are properly aligned with filament path.\r\n26. Porting MK2 firmware to Einsy had no effect. https://github.com/prusa3d/Prusa-Firmware/issues/602#issuecomment-387505791\r\n27. Implementing Z fade out of mesh bed leveling has no effect. https://github.com/prusa3d/Prusa-Firmware/issues/602#issuecomment-387505791\r\n28. Increasing E microstepping (and I have tested decreasing it) has no effect. https://github.com/prusa3d/Prusa-Firmware/issues/602#issuecomment-387505791\r\n29. Prusa made a custom MK2.5 with an MK2 head, no change. https://github.com/prusa3d/Prusa-Firmware/issues/602#issuecomment-387505791\r\n\r\n![extrusion](https://user-images.githubusercontent.com/8582658/38383023-ffe31bb8-38d0-11e8-88f9-78798cd8b2e6.jpg)\r\n![439ac03b-cdb8-4bb9-ab2d-93fc22ee58ff](https://user-images.githubusercontent.com/8582658/38383027-02e4859a-38d1-11e8-8d35-ae98282a631e.jpeg)\r\n![7c0698a6-a967-4ff5-826e-c872171844f5](https://user-images.githubusercontent.com/8582658/38383031-04aab840-38d1-11e8-9fd0-ce7b2f4b7339.jpeg)\r\n![img_20180315_220019](https://user-images.githubusercontent.com/8582658/38383035-07ca1e58-38d1-11e8-86e4-aa365c50e951.jpg)\r\n![img_20180315_191206](https://user-images.githubusercontent.com/8582658/38383039-0954c5a2-38d1-11e8-94e0-37b6be14afba.jpg)\r\n![20mm_perimeter](https://user-images.githubusercontent.com/8582658/38383041-0b092096-38d1-11e8-9a2a-51d1eb66502d.jpg)\r\n"},"comment":{"url":"https://api.github.com/repos/prusa3d/Prusa-Firmware/issues/comments/389229615","html_url":"https://github.com/prusa3d/Prusa-Firmware/issues/602#issuecomment-389229615","issue_url":"https://api.github.com/repos/prusa3d/Prusa-Firmware/issues/602","id":389229615,"user":{"login":"venci1ty","id":38466356,"avatar_url":"https://avatars0.githubusercontent.com/u/38466356?v=4","gravatar_id":"","url":"https://api.github.com/users/venci1ty","html_url":"https://github.com/venci1ty","followers_url":"https://api.github.com/users/venci1ty/followers","following_url":"https://api.github.com/users/venci1ty/following{/other_user}","gists_url":"https://api.github.com/users/venci1ty/gists{/gist_id}","starred_url":"https://api.github.com/users/venci1ty/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/venci1ty/subscriptions","organizations_url":"https://api.github.com/users/venci1ty/orgs","repos_url":"https://api.github.com/users/venci1ty/repos","events_url":"https://api.github.com/users/venci1ty/events{/privacy}","received_events_url":"https://api.github.com/users/venci1ty/received_events","type":"User","site_admin":false},"created_at":"2018-05-15T16:27:59Z","updated_at":"2018-05-15T16:27:59Z","author_association":"NONE","body":"@raspeitia  Just to say that i did few tests from 55 to 105 flow. And 60 seems to perform best.  But yes, this days when i have time i will do it again and share pictures . Meanwhile i would like to see if anyone could reproduce the result in the middle."}}
{"actor":{"display_login":"venci1ty"}}