geert_2
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Posts posted by geert_2
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Elsewhere I read that Blender sometimes produces defective models, not "watertight", or containing extra invisible planes and stuff, and thus not suitable for 3D-printing. Might be that? I don't know how to repair it though, as I don't know Blender.
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In my experience there are several sorts of blobs:
- Thick light brown blobs come from the outside of the printer: they accumulate on the outside, especially is there is a bit of overextrusion, and then they sag down and get deposited on the print, in a big blob, usually light brown. Upon the next passes of the nozzle, this blob is smeared out a bit.
- Tiny, thin black flakes come from the inside of the nozzle: this is PLA that has been carbonised inside the nozzle, against the walls, or in-between the nozzle and teflon coupler, and then comes free and is washed away via the nozzle. Most often after a cold start.
- Undiscoloured blobs (=not brown or black due to decomposition) can have lots of causes, for example due to layer-changes, the nozzle taking off or landing on a spot, very complex curves with a zillion facets where the printer buffer can not follow the data, nozzle oozing while traveling through air, etc.
But I have never seen any such drops jamming a print or printer.
Could you check and doublecheck if your temperatures are okay? If the nozzle would be way too hot (e.g. 250°C for PLA instead of 190-210°C), or the material flow way too low, I could imagine that the PLA would start to burn and carbonise completely in the nozzle? Then the coal might block the nozzle. Because the blob looks like burnt foam and coal on your photo, sort of?
When I once tried burning PLA in a bunsenburner in a spoon, it almost completely vanished. So it burned very clean, leaving only a thin layer of black powder dust, that I could wipe off easily. But that might be different with other brands of PLA. On the other hand, PET left a thick, glossy and hard varnish, difficult hard to remove. During combustion, both had a phase where there was bubbling black liquid, foaming a bit, similar to what is on your photo.
Also, be sure to clean off the nozzle after each print, so there are no remains. I do this immediately after a print finishes: I wipe it with a piece of thick paper towel, or leather cleaning cloth ("zeemvel" in Dutch), impregnated with PTFE oil, as this oil seems to reduce accumulation a little bit.
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Yes, that Z-dimension is an exellent idea, I hadn't thought of that.
Most of the time I use an older Cura-version, good enough for my UM2. But that only has a ";Layer count" in the gcode, no ";MAXZ", it seems. But together with the layer height jumps at the beginning of each new layer, that also makes it possible to calculate the total height.
And then double check with your ruler. 🙂
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I don't think so: as far as I know, a gcode-file only consists of machine commands like: move the head to this point, start extruding so much material, go to that point, etc. There is no 3D-model shape information in the file, no STL. Basically, it just moves the head and bed around, and dictates the extrusion.
I think the best way is to position your first model on the bed again in Cura, and do the same thing you did earlier. Chances are you are going to end up with the same scaling, because you follow the same reasoning as then. Or take a ruler and measure your printed model, and compare that to your CAD-design.
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I think software that can raster photos for traditional printing might work? For example an old Photoshop or so?
If you look at printed photos in books or magazines through a magnifying glass or microscope, you will see that they do consist of solid dots in varying sizes and angles. There are no shades in-between, only dots 100% (ON) or 0% (OFF) in the colors yellow, magenta, cyan, and black. By varying the size of the dots of each ink color, all the zillion colors shades in-between are produced.
So, practically, you would need to convert a color-image into black/white in an image editor, then adjust contrast to your wishes, and then export that greyscale image as a printing-raster or printing-screen (I am not sure about the exact terminology), to convert the grey-shades into black dots of varying sizes. In some professional printing softwares, you can also select the desired shape of the dots: square, diamond, circle, and you can select the angle under which they are printed.
Next time you walk by a huge promo panel on the streets, have a closer look. Usually they have big dots, easily visible to the naked eye.
I doubt if freeware like Inkscape or GIMP can do this too, because this is a typical professional printing feature, not required for home or office use. But you might find some software, I don't know.
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Since it seems to be running diagonally (as far as I can see on the photo), my first guess is that it is something with the glass plate? For example if the bed is dirty, greasy, or soapy in that area, so the print does not bond well? Or if you did use some bonding, maybe an uneven bonding layer (too thick/too thin)? So I would first do a thorough cleaning of the bed, and degreasing.
I don't know if autoleveling could cause such issues, if for example the probe would have encountered a piece of dust during measuring, resulting in an incorrect height measurement?
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I haven't printed with Breakaway yet. But in my experience with PLA and PET, thin black flakes usually come from the inside of the nozzle: this is material that decomposed against the wall of the nozzle, and at some time breaks free and goes through the nozzle. While thick lightbrown blobs of goo usually come from the outside: this is material that accumulates on the outside, often when printing with overextrusion, and then decomposes and sags onto the print in a blob.
Stay with the printer and watch closely: often you can see what is happening and why. Maybe you can also smell why and when the problem occurs (the cause).
Based on the color and the amount of blobs, I would guess that you print too hot, or with too little flow, or both. But this is pure guessing; as I have no experience with Breakaway...
What you can also do to reduce the amount of support, is design custom supports in CAD.
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Yes, for drywall I can imagine that it would work. I had to look-up the word drywall; here in Belgium it is usually called "gyproc", after a brand name. And everything is better than cutting with a hand saw... :-)
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Isn't that going to melt? What material are you going to cut? Let us know how it went.
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Just to make sure there is no confusion: in Ultimaker printers there are two sets of fans:
1) The nozzle cooling fan, blowing onto the upper area of the nozzle to prevent heat from creeping up into the filament. This is a little fan.
2) The model cooling fan(s), cooling the extruded filament and making sure it solidifies quickly. These are 2 somewhat bigger fans on my UM-printers.
I don't know if your printer has both sets of fans too?
I am talking about the nozzle cooling fan here, which should go on automatically, being hardware controlled, as soon as the nozzle goes above a certain temperature (40°C in UM-printers). As far as I know, there is no setting in Cura to control this, it is pure hardware. (I am not talking about the model cooling fan which you can select in Cura.) If that nozzle cooling fan is broken, then the print would start fine, but slowly the heat would creep upwards into the filament and melt it above the nozzle, causing blockings.
So, if your printer has a nozzle cooling fan, and if it is broken, that might be a cause. Sometimes you can hear if the fan bearing is worn-out and going to fail, when it is making rough noises, typically a sort of "rheu-rheu-rheu" sound.
But there might be other reasons too.
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Yes, for 90 kg fish, I can imagine that locking the line is not the best option... 🙂
But here the fish are only 1 or 2kg, so they don't pull anything - or anyone - into the water. The only problem is that these fish may sometimes dig themself deep into the sand, or below stones or debris, which makes it harder to pull them out.
Not a fisherman myself, it is just from seeing others.
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Years ago I did a manual on cleaning the nozzle of an UM2. It is not the official method, but it is more gently, without the hard pulling of the (back then) official method. So it is not as hard on the mechanics of the printer, but with equally good results.
Have a look here: https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/
It was for the UM2 (non-plus), but I think you can borrow most aspects for other printers too.
As for parameters to print: most of the time I use the defaults for the UM2, which are pretty good:
- for general PLA: 50mm/s, 0.1-03mm layers, nozzle 210°C, bed 60°C, fan 100%.
- for general PET: 0.1-0.2mm layers, nozzle 215-225°C, bed 70-80°C, fan off.
- for hight quality tiny models in PLA: 20-30mm/s, 0.06mm layers, nozzle 190-200°C, bed 60°C, fan 100%.
- for tiny high quality PET models: 20-25mm/s, 0.06mm layers, nozzle 205-215°C, bed 70°C, fan off.
- nozzle is always 0.4mm on an UM2 (non-plus).
The most common issues I have with the UM2:
- irregular underextrusion: teflon coupler is worn out, thus replace (once every 500h our so).
- regular underextrusion, PLA only: you are near the end of a spool, and it is wound-up so strong that it acts like a strong spring resisting unwinding, and causing a lot of friction in the bowden tube and nozzle. Then manually unwind a bit of filament, bend it in the opposit direction around a skater wheel, and release it. Now it is more relaxed with a bigger bending radius, causing no more friction and resistance.
- tiny black flakes in the print: the inside of the nozzle is dirty: clean with cold pulls, or my method above.
- thick brown blobs in the print: the outside of the nozzle is dirty, due to material accumulated on the outside, decomposing, and then sagging onto the print. Happens occasionally with PET, not so much with PLA. Treating the hot nozzle with PTFE-oil or silicon oil (when there is no filament in it), helps a bit, but does not eliminate it.
While you are at my internet page, have a look at my improved horseshoe clip too, and print a couple of them. That clip makes it a lot easier to remove the bowden tube.
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I can't help with the board and commands.
But I have one suggestion: if you are going to add extra motors and stuff, consider feeding all of them from a separate power-supply, all with their own power-transistors. And switch these power-transistors (or MOSFETS or whatever) on and off via opto-couplers. Then you have no electrical connections between the add-ons and the original main board, and thus the least risk of overloading or short-circuiting that board, or the original power-supply. Motors can give nasty spikes and oscillations that could easily destroy the main board, even with diodes.
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To me this looks like printed too fast, in too thick layers, and with not enough cooling indeed.
Your models seem to have elephant feet too? Which could indicate a bed-temperature problem. So I would check both your printing temp, and your bed temp? And as said above by gr5, check if all fans do work.
Does it have to be ABS? Or would PET be sufficient? PET has far less warping and deformation than ABS.
I have almost no experience with ABS, but for tiny models in PET, I usually print them slow, cool, and in thin layers. Thin layers gives the best accuracy. Printing slow also improves accuracy, and it gives the new layer enough time to melt and bond to the previous layer. And printing cool prevents the filament from decomposing and burning in the nozzle, due to sitting there for too long due to the low flow rate. For a small model in PET, I might use 20mm/s, 0.06mm layers, and 210°C (for PET with a recommended range of 215-250°C). That would give the quality shown below in my custom horseshoe clip. But I don't know if this would apply to ABS too?
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Have you tried a "known good" material, to see if it is the material or the printer?
Hard to say from the photos, but it looks a bit like it is burned? Maybe printed too hot, or wrong material setting?
Does your printer have a head/nozzle cooling fan? If yes, verify if that works well.
I don't know your printer, so this is just guessing...
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When I did print circles (tubes) at 0.3mm layer height and 0.4mm nozzle, I already noticed the layers would stay flexible for some time: upon the next pass of the nozzle, the previous layer would still move a bit. So on your 0.4mm high and 0.8mm wide layers, that effect could be far worse. It could also be the combination of slow layer cooling, plus heat radiated from the bed, plus a warm environment.
Have you tried putting a 30cm desktop fan - the same fans we use in summer to keep our heads cool - in front of the printer? Even at low speed it should provide enough air for additional cooling, just to evacuate the hot air. See if that makes any difference?
It could also depend on your environmental temperature and humidity: if too hot and moist (e.g. 30-35°C) that would also prevent cooling of PLA. Other materials that print at higher temps, like PET, ABS or nylon, would not be affected. But since PLA already starts deforming from 50-55°C...
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Ik denk best op internet zoeken naar grote tekeningen hoe dat ding er vanbinnen uitziet? Productie-tekeningen of zo? Daar zit een hendeltje en veertje met latch-mechanisme in, maar ik weet ook niet precies hoe het juist werkt. Als je het kaartje erin duwt, klikt het vast. Duw je nog dieper, dan klikt het terug los. Dus dat moet je zien te vinden. Het lijkt alsof dat eerste klikje niet meer werkt?
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Before I scrolled down and saw the answer, I was thinking about an antenne, or something.
You may have a very different fishing gear setup from the ones I sometimes see on the canals here? They have a spool that can be locked, so it doesn't unwind by itself. After being thrown into the water, the wire is always under tension, because there is quite a bit of metal weight hanging on it. They are fishing for fish that are living at the bottom of the water in the mud ("platvissen" in NL, literally "flat fish", but I don't know the English names). So I don't see how that would work here, and I wonder what gear you have?
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I would guess it is because of the heat? PLA print want to be cooled fast to below 50°C, otherwise they sag or deform. If you print 0.8mm wide and 0.4mm high sausages, that is a lot of heat. So I could imagine that they do not cool down and do not solidify quickly enough? So the walls stay somewhat soft, and are pulled inwards? Especially if the bed-temperature would also be quite warm. Molten plastic tends to be pulled into a thick blob. This is a guess, but it is the only thing I can immediately think of.
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When printing that slow, I usually print at 190°C for PLA, otherwise it may decompose due to sitting too long in the nozzle, because the flow rate is so low.
I don't know what nozzle you have, but I would suggest taking that width as line-width (e.g. 0.4mm if it is a 0.4mm nozzle).
Also, FDM printers like to print continuously, without too much retractions. So the flow through the nozzle is nice and constant. If it has to retract a zillion times on a very short distance, filament might be grinded in the feeder.
That milk crate has lots of gaps in the side-walls, it is maybe not the best model to print on an FDM printer. If you would change the walls into solid panels, like a traditional curver-box for storage, it would probably print much better. But the walls need to be at least one line-width thick.
I would guess the problem is a bit of all this? But it is a guess, not sure.
In the beginning, stay with the printer, and watch closely what happens, how it prints. Begin with simple test prints until you get them good. Then change settings on the fly, and see what effect that has on quality, while you keep watching. For example: on the fly increase and lower speed, increase and lower temperature, etc. Increase and reduce layer-thickness. Then you will get a good idea of the upper and lower limits, and the optimal in-between. The optimum may be different for each model, each model size, each filament. You need to develop a bit of a feeling for it, and that is best learned by closely watching it.
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If there are specific problem areas, where only one corner or area lifts and the rest not, you could design a custom brim in the shape of "mickey-mouse ears" around that corner to keep it down. This could happen if that area has a steep overhang, causing a lot of upwards warping forces. But this does not seem the case for you, it seems more general.
If the standard brim would not work, because it is too thin and still warps, you could design your own custom brims in the CAD design, and make it a few layers thick, for example 0.5mm. This is still reasonably easy to cut off with a sharp knife or scalpel (surgical knife). I sometimes do that for very specific parts.
For example in the design below: the pink and orange parts have overhangs, and are custom supports to prevent the yellow top from sagging. They do need a custom brim, a bigger ground plate, otherwise they would fall over because of their tiny ground-area. Usually I make my custom brims about 0.5mm thick. The hollow cube also needs one, otherwise the walls tend to bend inwards and the cube tends to peel off. This is just a dummy cube, to move the print head away from the yellow part, so the yellow has more time to cool down and solidify, otherwise it gets deformed. The shape has to be accurate, because the blue part has to slide through the yellow part (where the pink and orange supports are now sitting). This is a small model, text caps height is 3.5mm, text legs are 0.5mm, so I can't use heavy tools. The rest of the models don't need brims, they print fine.
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I can't answer your question, but out of curiosity: is there a specific reason why you would write your own algorithms? Instead of just changing existing parameters to suit your needs? Probably 99% of the work is already done by the developers, and you only need to change minor settings?
Unless it would be for a self-study project to gain more understanding, or for new scientific projects with other materials or equipment, or so, like printing in biomaterials or concrete. That would be very valid reasons. I don't want to invalidate it, I am just curious.
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It should help to put a bag of dessicant next to it too. The heat is required to shake the moisture loose from the filament, and the dessicant helps absorbing and removing it from the air.
But be sure to use fresh dry dessicant. Thus dry it separately in an oven, prior to using it here. Wet dessicant will release its moisture when warmed up, the opposite of what you want.
When storing filament, I always put a bag in the storage box too, so the enclosed air stays at a low humidity.
You can find this in car parts shops, it is used to dry cars and home mobiles in winter. Preferably use one that changes color when wet: here the blue dot changes to pink. (Note: the ruler is in cm)
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On 4/19/2022 at 4:37 PM, GregValiant said:
@geert_2 - I'm not sure what all of that means ... but I like it.
It means that the mind and spirit can have control over matter. If they are powerfull enough...
Weak minds are slave of matter, but strong minds can influence it.
After all, that is how we invent things: we first think them out in our mind, and then we materialise our thoughts in the physical world. Most of the time we do this materialising slowly and via a lot of deviations in CAD, and then via 3D-printing, or injection-moulding, or metallurgy and machining, or wood-cutting, or cement and bricks, or whatever means.
But people who are spiritually *very* strong, might be able to take a shortcut, and might materialise it directly by "thinking it into existence", so to speak. This direct route often works best if very strong emotions and urgencies are involved, thus in crisis situations. And thus unfortunately this often means in negative circumstances like incidents. For example: someone gets extremely mad because something doesn't work as expected, with a huge burst of anger-energy, because he needs it urgently. And then that huge power and energy outburst of his anger makes his decision or conclusion stick. Typically something like: "this piece of shit never works!!!" And thus, after that powerfull outburst of energy, it indeed never works again...
Generally, technicians, engineers, inventors, architects and artists are spiritually more powerfull than average people: that is why they can do things, why they can invent or create new things, they can materialise their thoughts and dreams into the phycical reality. It can work in a positive way, but also in a negative way.
I am not saying this is the case here. But if a problem can not be resolved by physical means, even though it should, it might be worth looking into spiritual decisions that made and old earlier similar problem stick forever. If there is an earlier similar incident, and you carefully examine that old thing of the past, and you remove those old conclusions, then you can make a fresh start.
Another example: if you are run over by a red sports car, with a driver in black leather suit, then after that incident you might tend to find red sports cars and black leather suits "bad", causing negative emotions and body reactions in you. Even if it happened long ago. That is due to a similar conclusion at the time of the accident. Lots of irrational fears, dislikes, or endless problems come from such unresolved negative decisions in the long forgotten past. Most of the time the reactions are just emotional, or materialising itself as an upset stomach (e.g. if you ever got sick from rotten food) or a faster heart-beat, or negative thoughts.But sometimes thoughts could materialise directly into other items, such as sensitive electronics. That is how the light-swiches from the past worked, to think the light on or off. They worked with a random-generator. By thinking the light on, you could influence that random-generator, and shift it slightly above or below 0.5 (if random flipping between 0 and 1). That level shift would be detected to switch the light on or off. Obviously this only worked for strong and positive people. Negative people ("this never works") got no or opposite results...
Good mind-control occurs also in telepathy: that is communication directly from one mind to another, without a long and cumbersome deviation via brain-cells, mouth and lungs, vibrations in the air, vibrations in the receiving ear, nerve signals to the mind, and the mind interpreting these sounds and translating them into the original thought, hopefully. Today, a lot of young people can't even do that anymore: they need lots of additional via's (=deviations): first converting their complex thoughts into primitive neanderthaler sentences, then into finger-movements, then via a cell phone and radio-waves to a 4G antenna, radio-waves from that antenna to a satelite, radio-waves from that satelite to a ground station, the CIA listening-in via automated spy-systems such as Echelon and PRISM, then back up to another satelite, then back down to another 4G antenna, another cell phone, text messages on a screen (these texts also via lots and lots of electronic via's to address individual screen-pixels), light-waves, eyeballs, nerve signals, and finally to the brain. Not very efficient, if you would ask me... And then they wonder why they have so much communication problems and are not understood...
Again, I am not saying this mind-thing is the case here. But there could be a spiritual factor, because of the "long unresolved streaks of problems". And if so, then this insight might help resolve it. But of course, don't rule-out purely technical defects such as a bad power supply, faulty computer chips, electromagnetic spikes on the mains, or spikes in the environment (e.g. nearby cell phones often cause spikes that disrupt computer screens, CPUs, USB-communications, etc.), too moist environment, compressed air that contains oil (and thus destroys bonding), and similar stuff... But you can see such purely technical issues clearer after spiritual issues on the matter are resolved.
How to get smoother prints
in Improve your 3D prints
Posted
This looks like very steep overhangs? In general, you get smoother prints when printing slow, in thin layers, and cool (=near the coolest edge of the temp range for the material). However, on steep overhangs, in my experience thicker layers give smoother surfaces: too thin layers tend to curl up.
Also, small objects can not cool down well, since the hot nozzle continuously sits on top of the same spot. That too causes such deformations. Here, printing multiple objects at the same time, and printing cool, may help.
Models with too many polygons, and thus too short line-segments, may cause the printer to stutter and also produce similar effects.
Not sure which effects are at play here.
Below: photo of too small areas with insufficient cooling. Printing a dummy tower next to it, improves but does not eliminate the problem:
Dummy model in inverse shape, for cooling (theoretical model):
Real dummy model (pink):