Reverse_Engineer

Hi guys I've been out of the loop since cura 3.8. I tried 4.2 today and I'm not getting an option to save as gcode. I can change the filename but my printer and/or octoprint won't print from it. I'm not getting an option to save as gcode, so maybe I'm just re-naming the 3mf file and not conveting it to gcode. Can someone point me in the right direction to catch up on 3mf and how to convert to gcode? I've been searching for about an hour and all I'm finding is redundant stuff that's not relevant. Do I have to upgrade octoprint or my firmware to print from 3mf. I'm using an old tevo tornado BTW

So I wasted another 100 metres or so of filament on this print with combing turned off, there was very little stringing until it got near the top of the print and then it seemed to make thicker strings than all the previous attempts. So anyway I viewed the layer view preview with the travels shown and it was generating travel paths in seemingly random places that went across the print where there was no material to be printed (just like the print did), it looked like a spider had moved in and made a web. So then I sliced the same file for another printer I have and all travel paths were confined to places that had material printed, seemingly eliminating the opportunity for strings to be drawn across the void in the print. Then I loaded the model back into Cura with the original profile for the first printer and sliced it again with all the setting as they were when I was having problems and checked the travel paths and this time they are all on printed surfaces. Nothing changed except the way Cura decided to plot the travel paths. So it seems like Cura can sometimes plot the travel paths in a way that leads to stringing across a void. I don't know if it's a bug or just a random slicing error, it's never happened before. I will be sure to check the show travels box when I check the layer view from now on though.

I don't know if you've printed it yet but another possibility would be to split the model into two parts and then glue or screw it together.That way you could print the face on its back and you'd only need supports under the two tabs on the front panel and along the slot on the stepper bracket. I'd split it along the red face on underside of the fascia in your model shown in your pic.

Reprap printer - cartesian PETG filament 1.75mm Cura 3.6 So I'm trying to print some parts with that have an open section in the center - a bit like a coffee cup I suppose and I'm getting so much stringing in the center where there should be nothing that it's basically ruining my prints. I've tried playing around with retraction settings, temp settings and travel speed and nothing seems to change. So I observed a print and when the strings are created the nozzle travels across the center of the print to start a new layer but the extruder doesn't retract and filament oozes out until it gets to where the next layer starts. So in my meddling I tried turning off combing and then the extruder retracts during travels and the strings are gone. This creates several other problems that degrade the print quality in other ways, the first layer has problems due to how it stops, retracts and restarts so much. When combing is on the first layer doesn't go through all those stop start retract moves and it works perfect. Having combing turned off also seems to create a lot more blobs both within the infill and on the outside of the print. So is there a way to enable retraction while combing is on? All those travels seem really inefficient when printing something with nothing in the center, that time could be better spent printing something. Is there a need for the nozzle to travel across the print like that between layers and is there a setting to stop it?

It's a bit hard to say without about a bit more detailed info on your settings. Just out of curiosity does the layer view still show areas with no fill if you set a finer layer height and width or set the shell wall thickness to a slightly lower value ?

Sorry to drag this up again. I thought I had this solved, printing from Cura with a USB cable connected to my laptop resulted in three perfect prints last night. Then today I did a print of a Unicorn my daughter found on Thingiverse and it displayed repetitive layer shifts along the Y axis. I can't say for sure but this seems to be a different issue to what I had before, there's no extra paths being printed off the job just (roughly) 0.5 - 1mm layer shifts with the rest of the printing as normal. I'm still not discounting your advice obewan, your suggestion could be a good diagnostic tool for this current issue. I was getting layer shift issues (also along the Y axis) when I first got the printer but I adjusted the output voltage of the Y stepper driver and that issue seemed to be cured. Those shifts were intermittent and very random, these shifts are almost what I'd class as in being a regular pattern. Now for a bit of speculation The only real difference I can think of between the last few successful prints and the one that just shifted layers was that my mrs was running the washing machine when it printed. Could it be possible that the washing machine motor could be spiking the voltage of my house wiring through counter EMF when the field collapses each time the motor switches off and is causing my problems? I'm not certain but I think it's on the same circuit as the outlet the printer and laptop is plugged into. I'll investigate that when the current load of washing has finished. Even if it is a different circuit both circuits share a common rail n the meter box before they connect to the breakers. Is a dirty supply voltage known to cause this type of problem ? Edit : To save dragging this up again I'll just edit this with an update. I just ran another print sans the washing machine running on the same circuit (I did determine that it's running on the same circuit) and it turned out perfect, so it seems the noise from the washing machine motor was having a deleterious effect on the printing performance in regards to axis shift. I'll mark this as solved now and put it to bed.

Sorry for the slow reply, don't you hate it when life gets in the way of your hobbies. I must admit I couldn't really get my head around the end-stop issue. I would have thought that would cause a layer shift or drift of some sort too. Anyway I ran a print through Cura over a USB connection to isolate the SD connection and remove that from the control loop. It worked perfectly and there's no more random stringing or unexpected movements off the print job. It seems that gr5 was on the right track, thanks mate! I was considering an octoprint setup, if I can't get the SD connector 100% reliable this might be the nudge I needed to commit to that decision. Thanks guys.

The firmware was already installed, it's Marlin 1.1 I believe. It's mid print right now & don't have a computer hooked up to it so I'm not sure if I can query the version right now. & I changed the SD card and played around re-seating it but it's still intermittently printing a mess off the job. I'll hook the the laptop up to it after the kids go to bed and query the Marlin version and run a print from USB to see if that proves or disproves the faulty contact on the SD card/slot. Thanks for the input obewan.

That makes perfect sense, it's an intermittent thing that only happens sometimes. Thanks for taking the time to answer and help me out, I really appreciate it. I'm printing from an SD card that has an adaptor to fit a mini SD card, so there's a few possible bad connections in the chain. I'll change that and see how it goes. Thanks again, I never would have considered that to be the cause.

Hi everyone I'm new to all this, so sorry if I'm posting in the wrong place or asking about something that's been answered ad nauseum. I'm using a newly acquired Tevo tornado and slicing my stl's with Cura 3.4.1 (appimage) on a linux host. Some of my jobs print fine but sometimes the nozzle will shoot off to the side or front of the job and keep extruding while it's off the print job. This is leaving unwanted strings all over the place. Sometimes it gets so bad the extraneous strings get caught up in a bundle which wraps around the the nozzle and ruins the print. Sometimes it wants to head towards X home and other times it heads towards Y home while it's off the job and extruding. I read somewhere that minimum layer time can cause a similar problem , so I reduced that to 3 and it didn't help. Besides including a purge/wipe routine in the Cura machine settings, I've never had the need to even look at G-code until now, so I must admit I don't really know for sure what I'm looking at but I can't see any X or Y coordinates in the G-code to account for the extra off job trips the printer does. The X and Y coordinates in the G-code seem to stay within dimensions of the job being printed. I first noticed the printer going off job at 0.6 layer height of the print in the pic and examining the first few layers of the G-code shows no off print coordinates I can see. It kept doing it during the rest of the print and ended up ruining the print (a ball of crap wrapped around the nozzle and snapped the top off the print). I don't know if it helps but I'll include my profile settings and my G-code after slicing if anyone wants a look. The strings were a lot worse than what you see here, I've started snipping them off with scissors and trying to get rid of them whenever I notice them. Any advice would be greatly appreciated. CCR10_My new Z nut bracket (narrow).gcode.zip Bracket profile (random strings).curaprofile