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Everything posted by yellowshark

  1. Printing the outer wall first is recommend for greater dimensional accuracy. Why has disappeared from my memory banks but that being the case it would be a reasonable factor for making your teeth work
  2. It would be interesting to see what the result would be if you reduced the number of walls to 2 and increased the infill to say 40%. I am not saying you are wrong but I have always used 2 walls and tailored the strength of the part by the density of the infill. I quite often print at 100% infill and have found on certain sizes/geometries that 100% infill is faster than using a lower density - important to us as print time is by far the major influencer on pricing whereas material has a small influence. .Also you do not say what print speeds you are using for infill and for walls. If they are all the same it surprises me that you are not seeing a gain but maybe my brain is missing something.
  3. If you are printing layers over low density infill it just means you need more top layers to get a decent surface, say 1.0mm thickness plus.
  4. Maybe it is back to basics, If you are printing top layers over infill why do you want to use bridging when it is not bridging. I do not have the latest Cura and do not know what bridge mode is, lol so probably should not be commenting!
  5. Very impressive @Safety_Lucas. What size fount did you use?
  6. Yes spot on. Depending on thickness dims I might use more walls if it proves faster to print that using infill. FWIW I also always use 15% infill overlap.
  7. One option is to use the "Ironing" function. From my very limited experience of this function its success will depend on the shapes contained within the top layer. An alternative is to design and print the model with an extra top layer, which has NO holes in it, i.e. just a complete rectangular shape to use your example. Then just cut the layer away with a craft knife where it is covering a hole.
  8. I use Repetier Host for my printing which basically provides this. I recommend that you also lower the print bed during the restart process to provide easy access to the material on the bed and then of course raise it back to its starting z position. I assume the restart will start with command 1 in the g-code so that the bed will be raised back to its start position including any z-offset command.
  9. Indeed, I am only concerned with the length in terms of configuring the e-steps
  10. I have never used wall overlap and never had zits. I only print my designs and designs all have the same wall width, irrespective of number of walls, i.e. measured nozzle extrusion width. I do not know what this thin wall lark is all about as I have never found a need to use a non standard design as I design to my environment.
  11. Hi @rob0213Rob, for future reference, especially if you have a lot more than 5 layers, inserting a z-offset command into the start g-code section of you 2nd(text) file is an easier way to do it, rather than changing all the z commands
  12. Thanks for that @geert_2, riddled with common sense and as you say, fundamentally it is your end result that is important not the method you used to get there
  13. No, I fine tune by printing a length of filament and measuring the filament on the print bed. Lol as you say you cannot get that accurate with a pencil! Well yes, the nozzle is attached to the extruder but the point of measurement is the nozzle tip before the move and then after the move No I do not say that. I tell Cura my nozzle is 0.45 and then change all my line widths to 0.45. I am not sure there is any point in telling Cura to print a line width different to the physical extrusion. People do but lol I have never understood why. That can only potentially introduce inaccuracies although admittedly at those dimensions it is probably not important.
  14. It would be helpful I think if you reprinted with 0.3 layers. This would clarify the question mark over whether these really thick layers are or are part of the problem and also we could then evaluate some of your other settings
  15. Lol @geert_2 that is changing the rules, I guess you could do an even better cooling job by putting the printer into a chest freezer 😁
  16. Thanks for that @gr5. I am not sure the sonotube/shute point is relevant to the point I was trying to make, which is that firstly you need more concrete to build a rectangular column than a circular column of the same dimension. A 15ft circular column with a diameter of 2 ft needs 47.1 cubic feet of concrete . A 2 ft square column needs 60 cubic feet. So if Cura uses a rectangular profile when doing its calculations – which was the stated point that I was questioning, it was not my point – then with a circular delivery profile (fine maybe it is elliptical but lol it looks circular to me) then are you not over-extruding by 27%? Also I remain dubious that 0.8mm nozzle would draw a 0.4mm line. A couple of years back I discovered my printer was drawing 0.45mm lines - with everything in Cura setup for 0.4mm lines - which I assumed was due to either wear and tear or manufacturing tolerance and so I changed Cura to 0.45 nozzle and line width and improved my prints.
  17. As an aside, although germane, is it possible to over-cool PLA (assuming ambient temp. is OK)? I have always thought the recommended fan setting is 100%, once you have printed the first few layers.
  18. Hi I suspect 4 top layers is a problem, that is only a depth of 0.8mm, I tend to aim for 0.9 to 1.2. And your infill % of course will impact this - the denser the infill the quicker you will close the surface.
  19. Lol, yes and don't know. The process you use for calibrating the extrusion length is pretty much the same as me except that I look for tighter tolerance, say 50 microns not <1000. When I start the calibration I do not extrude filament, I measure the movement of the nozzle and once I think the calibration is good I validate/fine tune the calibration by printing and measuring filament. Wall thickness and over extrusion. Not a simple subject but my view is that you are probably not over-extruding and my suspicion is that you nozzle diameter is 0.44 and therefore your Cura settings are wrong and line width and nozzle should be set to 0.44. I may be wrong but all I can say is that I had exactly the same thing a couple of years ago and corrected my Cura settings to 0.45 and saw improvement in my surface quality. It is probably worth pondering on this and trying some tests. Somebody, I think @geert_2, machined himself a probe with increasing diameter so that he can measure the internal diameter of his nozzle.
  20. The top surface is probably pillowing, i.e. you are not printing enough layers to close out the surface. Also/alternatively your fans are not running at 100% - I am assuming you are using PLA. With 0.3 layer height you will need at least 3 top layers, personally I would use 4 minimum to get the job done. You can always dial it back if you watch the print and see how many layers you do need. Generally speaking the thinner the layers the more top layers you need. So with 0.15 layers you will need at least 6 top layers but probably 8. Then in addition with the thinner layer you may need another 2 or 3. As before specify enough. Watch how many you do need and dial back if required. The bottom layer. I suspect this is over-extrusion and/or the nozzle being very close to the bed; nothing wrong in that but you need to compensate. I always run my nozzle/bed distance very tight and print the 1st layer at 70% flow to compensate
  21. Err yes it does! If you change from a 0.4 to 0.8 nozzle you will change your line width which will increase the volume of extrusion per sec. That is why you uses a larger nozzle, predominantly to reduce print time.
  22. Sorry I still do not understand, or rather I disagree. A 0.4 rectangle has a greater surface area than a 0.4 circle. Therefore if the calculation is based on a rectangular profile Cura will set the pressure/feed speed to deliver X amount of material per sec. If the calculation is based on a circular profile I would expect Cura to deliver Y amount of material where Y is less than X. So in your scenario Cura is delivering too much material. That would suggest that either you end up with over-extrusion or a nozzle blockage. I am no expert, I never studied fluid mechanics, but I do know that the filament that extrudes from my nozzle is circular not rectangular. So why do the Cura programmers do their calcs on a rectangular profile which does not exist? I am happy to be told I am wrong, lol if it is explained, but right now it does not seem logical to me.
  23. Never heard of anyone using a layer height a thick as 0.8, I cannot help thinking that this is one element that is probably causing a problem, but that is a guess, I have never gone anywhere near 0.8 Agree with @geert_2 on the cooling side. As a guideline I use 10 secs as my minimum layer time, with 100% fan, again I am guessing but with 0.8 layers you may need more than 10 secs. Also I would experiment with the extruder temp. Try 210 and 220 and gradually find the best temp; e.g. if 210 is better than 215 then try 205. With a layer height of 0.8 I am sure any temp. suggestions from us will be guesses.
  24. When you say the nozzle shape does not come into it could you expand on that a bit, it sure takes a lot more concrete to fill a rectangular column in a building than it does a circular column. I would have thought nozzle shape should come into it.
  25. Funny how we all do different things to get the same result. When you say "...if a filament always over-extrudes" I would say it does not, you always have the wrong settings. Get the settings correct and you do not have to muck around with flow%. I guess we come at this from different perspectives and probably nothing wrong in that. I use 70% flow for 1st layer, along with standard print temp (i.e. I do not set a different 1st layer temp) as on my printer flow % changes and stabilises a lot faster than a temp. change. And for everything else on all filaments/colours etc. I use 100% flow. I control my extrusion, i.e. no under-extrusion and no over-extrusion, with the temperature.
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