illuminarti
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Posts posted by illuminarti
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Some Cura versions have had problems opening dialog boxes. If the window doesn't show up, try clicking on the dock icon for Cura, that usually fixes it.
Regarding the communications issue, sometimes the OS will rename the port based on boot order, I think. Therefore, I suggest you look on the drop down and see if another similarly named port has shown up now.
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Jimmy - I strongly recommend that to I attach a gcode file here so we can check it out. (If you click 'More reply options' then you get a different user interface that lets you attach files).
No, the steps-per-e is absolutely fundamental to the print process. The slicer looks at the length of line segment that you want to print, and based on the nozzle width and layer height, it calculates the volume of plastic needed at the hot end during that part of the print.
Based on the declared width of the filament, it figures out how many mm of raw filament it needs to feed into the cold end of the system to get that volume. And the gcode specifies that number of mm for the e move on that line of code.
The steps-per-e is what the firmware uses to figure out how far to turn the stepper motor to get that many mm of plastic fed into the Bowden tube, and hence that volume of plastic squirted out of the nozzle. If your steps value is wrong, then you get either too much or two little plastic for the segment being printed.
A few percent error isn't going to make too much difference to a print - except perhaps if you already have a bit of z-error on a narrow first layer, so even the right amount of plastic is struggling to get out. With the latest stock equipment, the general consensus is that the 'right value' is about 830.
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BTW, if you're trying to print very thin layers (less than 0.1mm) then maybe try setting a thicker first layer - perhaps 0.2 or 0.3mm). That will make any z-level inaccuracy less critical, and give you a better shot at getting the first layer down well for everything else to build on.
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Hi Jimmy, welcome to the forum.
Looks like your first layer height is close to the bed - maybe a touch too close, it's hard to tell. In general, I wouldn't worry about that, as you're getting a nicely squashed first layer, that should stick well. But then there's all the blobbing, which I think is excess extrusion escaping when it can. So the question is - why is there so much extrusion?
What layer height are you printing, and are you requesting extra thickness for the first layer? Also as George mentioned, do you have the packing density set to 1.00?
You may want to check your steps-per-e again, and also the filament diameter. It might be helpful to attach the gcode file here, so we can take a look and see if anything seems odd with your settings.
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Yes, the green grease is only for the z-screw. For everything else, I (and many others) use sewing machine oil.
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This is a tricky thing to print the way that you want it - because you're modeling the upper circular part as a hollow STL, the slicer is printing two walls - and outer one, and an inner one, each one loop thick, for two loops over all.
Best option would probably to model it with the upper cylinder solid, and then slice it twice - one normally, and one with zero infill, and wall thickness = nozzle width. Then manually merge the gcode files together at the transition point.
(Or slice it once, and edit out the solid-base-in-mid-air that it will try to print on the upper cylinder?)
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It was openly discussed and, indeed, featured on a giant banner at MakerFaire.
I cannot confirm or deny the development of a dual-extrusion kit.
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Cura does allow you to specify the nozzle diameter that you are using, and takes that diameter into account when planning the toolpaths that it uses.
Nonetheless, overall parts diameters are going to end up slightly off, due to both mechanical imperfections and variability, and the fact that plastic contracts as it cools.
The effects depend on the particular model geometry, so typically you have to adjust the model on a case-by-case basis.
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Actually I used it a while back when printing an airplane only .4mm thick (2 layers). But other than that I don't use it anymore.
I may have mentioned it in an earlier thread when this came up - but I find that I get really good results for thin flat things, printing PLA at 230º directly onto polyimide tape on my non-heated bed.
It's hopeless for thick or tall objects as there's not enough long-term adhesion to resist warping and keep the object fixed for the duration of the print. But for objects with a large surface area, and only a few mm high it works really nicely.
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I think that the Z-axis screw needs to be moved down so that it is seated on the coupler, and the thinner part is pretty much hidden inside the coupler.
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Glad you sorted out the problem. Lubricating the rods helps a lot. Make sure you use light machine oil though, not the green grease that comes with the kit - that is just for the z-screw. If you put it on the horizontal rods then they will gunk up pretty quickly (I speak from experience).
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Hear, hear!! They look great - I hope I'll get a chance to install them soon. Thanks to both of you for making it happen.
Since I'm taking it all apart, I figure it's probably a good time to replace the belts too... anyone got any advice on what's the best thing to replace the stock belts with for use with these pulleys?
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Welcome, Sam!!
If you have some photos of your hot-end, it might help us identify any obvious problems.
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Thanks, Daid!! I'm looking forward to trying out this evening.
And thanks for thinking about the speed issue - I think the base is one area where the slicer can be smarter on behalf of the user.
Speed in general is a thorny issue, I think. I'm certainly not one to advocate speed at all costs (especially on new machines with inexperienced users) - I think the volume/sec limitation is something that isn't as widely appreciated as it needs to be, and speed for its own sake just stresses everything more than is good for it.
At the same time though, I think a lot of users are way more cautious than they need to be in choosing their print parameters. Sometimes as I see users on here, or in off-list discussions, talking about how long some parts take to print, I'm amazed they have the patience - they're taking several hours, days sometimes, to print things that my gut tells me could be printed far faster and with little if any noticeable reduction in quality (and, sometimes, even with better quality).
Now, of course, there are always exceptions, and some people have specific needs or visions, and really need that last percentage point of print quality. But I think that a lot of the time people just don't realize that it's ok to go faster... maybe they got burned at the really fast end of things, and over-compensate now. I wonder if it wouldn't be possible to make some kind of wizard based on analysis of the print during slicing, that recommends a range of print speeds and quality settings...
You've been gathering usage stats in Cura now for a while, Daid... is anything interesting emerging from the data that is being reported?
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MrcDesign - I don't think it's turned on, no - but I could be wrong. One way to check is to load the gcode back into cura using the 'Load settings from gcode' option, and then go see if that got set. But I don't think it does.
Is the layer offset too by a small amount, so that it wanders around a bit as the layers build up, or is it a pretty large offset - 5-10 cm or more? If its the former, it's almost certainly that one of your pulleys is loose, and slipping slightly - or maybe one of the short belts is catching on the frame?
If it's the latter, then I think it's because some part of the fast travel moves are failing when changing layers. If you have an UltiController, you might check what your acceleration speed is (Control -> Motion -> Acc) and try lowering it to say, 3000, if it is higher than that.
Also, try moving the head by hand when it's powered off, using fingertip pressure on the sliding blocks. It should slide equally easily in both directions. If there is any stickiness in one or other axis, check that everything is square, the end caps aren't too tight on the rods, and then add a little light (sewing machine) oil to all the rods.
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It's regular Scotch 2090 (aka 'Blue Tape'), custom cut in 6" widths. I get mine from tapecase.com. It's a little pricey in single rolls, but I'm thinking of buying a bulk lot and reselling it when I open my store, as it saves soooo much time, and really helps with print quality.
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I generally assume that I'm going to sacrifice the tape for every print - I'd rather make sure that the object stays stuck, than worry about re-taping the bed. I use 6" wide tape, so replacing the tape takes no time at all, and the lack of seams helps ensure better adhesion, and a cleaner bottom surface.
If the tape gets stuck to the bottom of the print, just stand it in a few mm of alcohol for 5 or 10 mins - the tape will then slide off cleanly, leaving an undamaged bottom surface, with the tape crepe-paper pattern still intact.
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You could also slice with top and bottom fill and remove the first X layers from the GCode.
But only the infill part... or else add gcode to fake the z-coordinate, otherwise you'll be printing all the upper layers in mid air. :-)
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Yes, it is.
But it's also a great way to improve the user experience for all UM owners by encouraging them to reduce print times, while maintaining while maintaining quality. Printing the base of most prints is a major pain and time drag, and I suspect that a lot of people could significantly speed up total print times if this bit could be optimized - and in my testing, there's a lot of room to do that.
This "layer 2 different speed" is such a simple plugin. In fact I think there is already one existing. This is the easiest kind of plugin to write or to take an existing one and modify it. This is a great case for a plugin.
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Set the bottom/top thickness to be non-zero. In the new 13.05 Cura beta, you can turn off top and bottom thickness separately. You're probably also going to need to print with either infill, or some sort of support in the middle to help hold up the top. The slope is so gentle that the loops don't touch one another.
If you really have to have it totally hollow, then the only options are going to be to print slower and cooler, and with even thinner layer height, in order to get as many passes as possible over the troublesome area.
Also I'd turn off duplicate outlines. It isn't helping here - it just prints the exact same thing twice, at half the height. If you're going to take the hit to print twice as many passes, then you *want* them to be different in this case, so that the slopes get smoothed out better. Duplicate outlines is a kludge that causes problems in a lot of cases, and it's only benefit is allowing you to print infill half as often as you print perimeters. Since you aren't printing infill here, it's of no real benefit.
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You may want to try reducing your x/y jerk setting (under Control -> Motion on the Ulticontroller) to reduce the stress during direction changes. That's the biggest source of rattling on mine.
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Why did I use G0 for moves? Well, because I see the option to have different feedrate modifiers for G0 and G1, which would make it possible to influence the print speed separately from the travel speed.
Which is exactly why I'd like to have other G codes for other aspects of the print. :-)
And regarding the first layers... I was being polite. :-) Unless my z-height has just gotten grossly out of whack (which is obvious the moment the skirt starts), I get 100% first layer adhesion every time, and zero base warp. I do my first layers at 70mm/s usually, and only re-level the bed every week or two.
Which is not to say that you don't get different results with your use cases and hardware. But I still think that it would be very useful for those of us that can to have a bit more flexibility in the speed selection.
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Yes... which is why I'd be interested to only turn it on for finished flat surfaces and/or have aesthetically aware path ordering for finished surfaces. :-)
1 small blob is easier to clean up than a stripe all the way across the surface of a print.
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But isn't raising the z height for moves (especially on exposed horizontal surfaces) almost as good as teleportation, and quite a bit easier with current technology?
Help: one axis starts shifting in middle of print
in UltiMaker 3D printers
Posted
You're most likely skipping steps on fast travel moves. In the x direction, certain fast moves are failing to happen, causing the head to lose track of its position.
I'd check how easily the head slides around by hand in y and, especially, x directions. If there are any tight spots, or x is generally tighter than y, then make sure everything is square, and apply sewing machine oil to the rods.
The infill pattern looks pretty rough - extra resistance from catching a blob might indeed have triggered a skip. The other thing you might look at is checking your acceleration speed: the more recent default of 5000mm/s2 seems to cause problems in some set ups. I'd try lowering that to 3000.