bcsteeve
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Posts posted by bcsteeve
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That sounds perfectly logical.
Often times, the 3D printing community is the blind leading the blind, and sometimes certain things that appear to work (or make some logical sense) becomes pervasive, and when you see the same guide/advice repeated through the Internet, I suppose it is sensible to assume there's some truth. But that doesn't mean it necessarily is!
I admit I didn't put a lot of thought into it. I was printing some guy's puzzle box and everything was jammed up. He helpfully had a test print and all signs were pointing to over-extrusion. I found one of many guides and calibrated e-steps then did the single-wall cube test and ended up with my ~85% settings... and the puzzle box worked. Does that mean my settings are right? Not necessarily. Perhaps he subscribed to the same flawed logic and has his set to 85% (or whatever) and tweaked his designs for that result. Who knows?
But I am happy with my current settings other than this stringing, which I'm also now happy to report I've resolved. I had my retract distance at 2.0mm as you noted, and I often saw advice to start at 2mm and adjust by 0.1mm as needed, but nothing really said which direction. I suppose I thought if zero meant bad stringing and 2mm was a good starting point, that the proper direction would be to go higher. I tried 3mm, 4mm... nothing helped.
Finally I printed a tower just now with 2.0, 1.6, 1.2, 0.8, 0.4 and 0... clearly there's a winner!
So really, my problem is solved. It wasn't the question I asked, but I'm good. And I very much appreciate your assistance!
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I tried all the settings changes... this is still the preview, which has me thinking it'll still be a spiderweb mess 😞
That's pretty much what the preview looked like before those changes.
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Hi @GregValiant
Firstly, thanks so much for taking the time to help.
Quote- You can try going to 4 walls and 0% infill.
I actually did set it to 99 walls prior to printing... typical for lithophanes. I guess I reverted that prior to saving the settings I uploaded.
Quote- You have "Max comb distance with no retract" set to 30mm. Drop that to 3mm to force more retractions. That should allow you to turn off "Retract before outer wall".
Thanks. I'll give that a shot
Quote- I see you have the retraction distance set to 2.0mm. You have a direct drive on your printer?
Correct
Quote- The setting "Avoid printed parts when traveling" tells Cura to compute the travel moves off the part. I think you would be better off with as many combing moves as possible within the part.
I wondered about that. I tried with and without and it seemed to make no difference.
Quote- In Travel - set the Layer Start X and Layer Start Y to the same numbers as your Z seam location.
That's something I hadn't thought of! I'll give that a shot as well.
QuoteI see you have a lot of Flow settings at 85%. Is there a reason you need to under-extrude by so much? Single wall calibration cube perhaps? This is not a single wall print.
Ok, so extrusion is something I've only recently bothered trying to calibrate, and yes I was going by a single wall calibration cube as per... well... just about all the tutorials out there! Of course this is not a single wall print, but surely the calibration universally advised isn't just for single-wall printing, right? I do have to say, I've had much more accurate printing results since changing to the lower figure. 85% is actually one of my higher ones. Most of my rolls calibrated out to 82 to 83.5%. With that said though, I have noticed some under-extruding issues, and this model was a prime example, in that there are little pin holes in the thinner areas that shouldn't be there.
Do you have a tip on best practices if you don't think I'm doing it right?
Thanks!
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I've got my printer pretty dialed in. I use Cura 5.2.1.
I go to print a standing lithophane for my kid, and I get some pretty bad stringing. Weird. I figure it is the filament so I go to a known good roll... same thing. Investigating, I look at the travel lines and I see a ton of them! There shouldn't be any, or very few, as I have combing set to All and I've never really had stringing issues with that enabled.
I play around a bit, and I notice if I scale the model 300%, then almost all of the travel lines disappear (or, rather, they follow the route of the model as they're supposed to with combing). But at 100% or even 200% I get a ton of straight across travels, which is very much counter-intuitive to that setting.
I gather it has something to do with the thin walls of the lithophane, but is there some requirement for combing that a wall be a certain thickness? If so, what is that thickness?
I've uploaded my project which is after I've done my best to minimize the travels, and it is still really bad, but at least contained to the back where I can clean it up easily enough. Without tweaking the z-seam alignment and increasing the minimum thickness of the model, it was like a spider's web!
I've done lithophanes before without an issue, so I'm not sure why this is a problem all the sudden.
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Hmm, I just tried again but with -0.25 instead of -0.15 and I swear it made no difference.
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If I'm to assume that it is correct and not being ignored, then I my best guess is that G1 physically moves the nozzle to 0.75 and then G92 tells the machine that it is at 0.9. Following that, the next G1 has the machine move to what it THINKS is 0.3, but is in fact 0.15.
If I have that right, is the .9 figure arbitrary?-
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I'm a bit confused by the Z0.9/0.75 figure because as far as I know, that's not anywhere in my settings... but it is the Z0.3 that is the concern of this topic. 0.3 is the initial layer height. Z-offset is -0.15. So why is the line after SKIRT not Z0.15? The LCD on the machine also reports 0.3 during the first layer. So my question is: is the z-offset being ignored after whatever that 0.75/0.9 thing is? Or is the Z0.3 really Z0.15 and the nozzle really is 0.15 lower than it otherwise would be?
G1 F300 Z0.75 ;adjusted by z offset
G92 Z0.9 ;consider this the original z before offset
G0 F4500 X35.683 Y63.404 Z0.9
;TYPE:SKIRT
G1 F300 Z0.3
G1 F1500 E0 -
Cool, I appreciate the response and especially considering it for a future release. Meanwhile, I can tackle it in alternative ways.
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Cura knows the size of the object being sliced (it says it down in the bottom). Let's say I want to send a G29 command to the printer suffixed by the size of the print job. For example, I'm printing a 50x50 object I see no reason to wait 5 minutes while it autolevels across a 300 x 300 bed.
I see other applications as well and I wondered if there was a way for me to instead of say "send G29 at print start", say "send G29 X{x of project] Y{y of project]" or even better (if I want to get complex) something like this psuedo code: "send G29 P{int(print size / 25)" {the idea being to scan a smaller grid number for a smaller grid size).
I hope I'm making sense.
Basically: can variables be used to dynamically generate gcode based on data generated by Cura (primarily object size)?
What are the criteria for combing to work?
in UltiMaker Cura
Posted
Yep, what you say makes perfect sense. I appreciate your taking the time.