geert_2

Watermarks do reduce strength of the model, obviously, since there is no material there, and the gaps might concentrate stresses. Apart from that, I never had issues with internal watermarks. Except if the hollows are too big, and their "roof" doesn't close very well: then you see some spaghetti or grape-like blobs sagging inside. And if they are too deep into the model, they become invisible or blurred, due to the layer lines acting as a blur filter. But this is just cosmetic. In my keychains above, it hasn't caused any mechanical or software-trouble. Originally I made watermarks by subtracting the watermark text from the main model. But this proved unnecessary. It is sufficient to just move the text inside the model, without any further operations. Then, upon export to STL it is automatically subtracted correctly, since STL are just triangles without any meaning. As far as I understood, "watertight" has nothing to do with hollow design features like watermarks, but with the edges of the model touching each other correctly. If you fold a paper model incorrectly, it has gaps in the seams, so it is not watertight. The same in STL: edges of triangles not touching each other. I made these keychains in DesignSpark Mechanical, and exported to STL. Don't use SketchUp: this causes problems with watertightness indeed: its vectors don't match, and they don't close gaps in the seams. Concerning the reinforcement of holes, I think this is possible by defining a different infill percentage around the holes. But I don't know the details, so I will leave that to others.

My experience is that usually I have to drill out holes anyway, because of occasional little blobs, strings and hairs. I also tend to make them 0.5mm wider in CAD than necessary: thus 4.5mm for a 4mm hole to slide an M4 bolt through. And then I *manually* drill it out (see photo). This only takes a few seconds. No electric drilling, especially not in PLA, because it melts immediately.

I have seen this problem too in long prints: while printing, the model sticks to the glass very well: no lifting/warping at all. But after removal, it starts to deform slightly. And indeed, for PLA usually the center "lifts" half a mm, if you put it on a flat table. So this must be due to residual cooling stresses in the material, which are not enough to pull the part off the glass, but enough to slightly bend it. However, I don't have a good solution: warming it up again to release the stresses, tends to make things worse, far worse. I have had models warp upwards on the edges. Or others warping upwards at first, but then after some time reverting and severely warping in the other direction, very weird. And they shrink in length, but expand in width and height with several percent. Maybe, if you could clamp the model between heavy metal plates, and gently warm it up to around its glass transition temp, and very slowly cool down, you could remove some of these stresses? Or let it sit for a night on the warm glass bed of the printer, before removing it (and cover the bed with a box, so temp is uniform)? Edit: the photo shows some of the warped test models. In this case they were subjected to way more elevated temperatures after printing, to try the effects of annealing. Thus way above glass transition temp. But the bending upwards in the center shown in the second model, is also very lightly present in 20cm long models, immediately after removing from the glass (although far less than shown here, only ca. 0.5mm).

With an ohm-meter, try measuring if the nozzle is grounded indeed. (Edit: do this only when the printer is switched off, and disconnected from the mains supply, of course!) But glass itself is easily charged, so there is always a possibility that heat and airflow do charge the glass and the lower part of the print, even if the nozzle would be grounded. Or by pulling the print off the glass. This is guessing, but I think the main charge on models will come from post-processing: grinding, cutting off defects,... And it will depend a lot on the material. Do dust and small particles stick to your prints? Then they are charged. There do exist anti-static sprays: in the old days we used them on CRT displays. The glass of those big color monitors tended to get so charged up that you could pull sparks of several centimeters, causing sore arms, and burn-pits in the display, due to their 30000 Volt transformers. Maybe you can still find those sprays?

Yes, exactly the same as I use; found it in a car accessory shop. :-) If you want to remove moisture from already bad filament, I think it is best to use both: a big bag of silica gel, in a hot environment (a sealed box on a heated printer bed, or in a computer-controlled oven). The elevated temperature might be necessary to dislodge the moisture from the filament. But be sure to stay below the glass transition temp of the filament, so it does not deform or melt. And then, once dry, store it in a closed box or bag with the silica gel.

The purpose is to reduce inertia. Each gram less improves print quality, because you get less vibration, less "ringing" around corners, less overextrusion at corners (the nozzle can accelerate and decelerate faster), and you can print faster. A drive motor weights a lot, compared to the rest of the head. If the head is lighter, the gantry can also be made lighter, which further improves print quality.

I would suggest you first practice your soldering skills on a broken harddisk or USB memory stick, or whatever else broken equipment with similar small chips. The main risks are that you damage the contacts on the board while desoldering, and next that you make short-circuits while soldering. Search on Youtube for tutorial videos, as there are a few tricks that can help. A video can say more than 1000 words. :-)

I think the underlying cause of the printer-interruption you experienced, is that when a computer reboots, its USB-bus is always reset. But I am not a programmer, and I don't know if attached USB-equipment is supposed to be reset too? Or is it allowed to ignore the bus-reset? An argument pro resetting is that when a device is hung-up, it is reset and freed again, one of the purposes of rebooting. But for long 3D-prints, yes it can be inconvenient...

This one has nice translucent colors. Maybe you can polish it a little bit, and brush off the white residu, but leave it unpainted?

I have designed a compact spoolholder for myself, but it only fits one standard spool (Ultimaker, colorFabb). So, in its current form it won't work for you. But you are free to re-use the basic concept, and adapt it to your needs: you will have to make it bigger, and stronger, so it can support the extra weight. It uses one standard 608 bearing (=same as in most skate boards), which is centered. Keep in mind that frictionless spool holders also have a disadvantage: the spool may unwind by itself, especially near the end, if wound too tight. So you may need to provide extra guards to prevent this. This design is made in DesignSpark Mechanical (=a limited version of the commercial SpaceClaim, distributed by RS-components, and free after registration). If you have this software, you can edit the design. See here for the concept and files (and then scroll down a bit). https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/ Purple = 608 bearing; blue = bolt and nut; cyan = base attached to UM-printer; yellow, lightgreen, red = rotating spool holder.

If it is a "brand new" printer from 2017(?), maybe the filament has just gone bad? It is well known that PLA gets harder and more brittle over time due to internal crystal changes, and PVA absorbs water and then may fail too. Or maybe there is something else you overlooked or were unfamiliar with, for example some settings? Or there might be a manufacturing defect indeed? I would suggest you do a test print, and show *exactly* which settings you used, and show what the results were, both while printing and afterwards, with good close-up photos, and with all the files (STL, project,...). Then maybe people can already diagnose it. It could be something very trivial, hopefully. I have made 1000+ good prints with the previous model (UM2), and I have seen lots of very good models made with UM3 printers. So it should work well, or at least can be made to work well. But settings and characteristics differ a lot from liquid light-curing resin printers. Might be part of the learning curve. We all needed to do several prints before we got the hang of it, and it can be frustrating indeed in the beginning. You should be able to get results similar like these, without problems:

It looks like the even and uneven layers consistently are shifted half a mm? But both are still present, it seems. Are both nozzles seated correctly in their holders, without any play? Or is the switching mechanism causing the issue? Maybe you can see if there is any play, if you watch closely while making a small test print? But I don't have a dual nozzle printer, so I am just guessing.

If you look at the layer-view in Cura, I suppose it shows support in those areas? If so, it looks like there was no support at all in the areas where the spaghetti occured? Maybe the PVA-nozzle clogged and stopped extruding PVA, or there was huge underextrusion? (Too wet PVA?) But I don't have a printer with dual extrusion, so I can't give much suggestions for handling.

Yes that is going to have an effect. The bigger the contact area of the bottom layer, the better it is going to stick. And the smaller the design elements, the easier they can bridge gaps without turning into spaghetti. I don't know the official terminology, but usually I speak about "raised" or "recessed" text or design features. So if the recessed seems to work better, definitely try that.

The purpose of printing via SD card is to completely separate your printer from your computer, so they can't influence each other. Whatever you do on the computer, can't have any effect on the printer, as there is no connection. Or maybe you forgot to disconnect the USB-cable?

In your photos, the next layers have nothing to stick to, so they print in the air and are dragged around. You need to find a way to make them stick. It is like when the glass bed is calibrated wrong, and you have too much distance between nozzle and bed. What about trying this method: - make sure your nozzle is rather close to the glass bed, so the first layer is squished very well into the glass, - make the indentations 0.11mm deep in the CAD design, - make the first layer 0.10mm thick in Cura, - make the following layers 0.2 or 0.3mm thick in Cura, Then the first layer is really squeezed into the glass, and there is a good change that the following layers will still have enough bonding. I am not sure this is going to work, and if the pattern is going to be visible enough, but it might be worth trying? This is what the bottom of the first layer should look like:

What about printing this model flat on its back? Then there are no bridges, and no drooping spaghetti? Just rotate it 90° in Cura. Otherwise, if you do not use support, then on the highest point of the bridge, the filament will allways sag because a molten plastic (liquid) can not keep its shape without support. It needs a base to glue itself to, such as a solid previous layer.

Maybe this behaviour is because sometimes the outer wall encloses multiple inner walls at once? For example when printing a lot of small circles touching each other. Then the inner walls may all be separate circles, but the outer wall might enclose them all at once. So it is just one uninterrupted outline. Just guessing, but I could see this as a reason. Edit: or vice-versa, as in this picture below: here the outer walls around the holes are separate circles, but the inner wall is one long connected outline.

I tried doing this manually: cut both ends at 90° angles, hold them together in a custom device (see pic below), heat a knife in a flame, put the hot knife inbetween both filament ends and melt them, remove knife, push both molten ends together, and let cool. Then you need to grind away the flange at the seam, otherwise it will not pass through the bowden tube and nozzle. You need to melt both ends to get a good bonding, then it is almost as strong as new. This method works and can especially be usefull for artistic purposes: to melt lots of different colors together. But it is not worth the time and hassle for me. So I use the left-over ends for doing atomic pulls, or for other purposes where I need a bit of plastic. For example you can heat a left-over strand, and ply it around something else (think of cable binders). Or ply them into hooks or clamps, or whatever.

Maybe there are different infill patterns, or infill percentages, in which the nozzle follows a different traject with less starts and stops, and less jumps? I don't know if this is possible, but just guessing. Check this in layer view in Cura, before printing.

It appears that OpenGL is coming with the graphics drivers. OpenGL is a specification to which drivers and hardware have to adhere, it is not a driver by itself. I am just echoing what I read on internet here (and hope it is correct), I am not a programmer. :-) So the latest graphics driver should give the latest version, if the hardware supports it. And if the manufacturer delivers new drivers for your system. Search for: "windows how to update opengl". Also there might be incompatible or buggy drivers, so in such cases you might need to try a different version, higher or lower than your current version. I am not sure, but I vaguely remember something that this was the case with some Intel laptop drivers?

On the older spools that I have, the material is indicated: PS (=polystyreen). Other spools might be ABS, PC,... But I don't know about the newest spools. So yes, these old spools should be recyclable perfectly. (But I am not an Ultimaker representative, just a user, so this is not official.) But even if the spool would not be recycled, but only recollected in the general "rest" fraction of garbage, and be burned, it is probably still way more environmentally friendly than glass or cardboard. Cardboard requires killing lots of trees to produce it. And glass requires at least 100x more energy to melt than plastic. And you don't get any energy back from glass at the end of its lifecycle (which for glass bottles is only 6x re-use, plus a lot of dangerous chemical cleaning liquids in-between each cycle). Modern burning-installations use the heat from burning garbage to produce electricity and warmth for heating buildings, or for industrial processes (for which otherwise other energy sources would have to be found). The exhaust gasses CO2 and H2O (carbondioxide and water vapour) are food for the plants and trees. Today there is not enough CO2 in the air, only 0.03% to 0.04%, and most plants are on the edge of extinction. Below 0.02% CO2, all plant life dies. Ideally, there should be between 4x and 10x more CO2 for optimal plant growth, than now. Yes, way more CO2, not less. Which is scientifically proven in large scale research projects, and even in every greenhouse: they inject a lot of CO2 in their greenhouses to increase growth and production. The rule is: 10x more CO2 gives 6x to 7x more green, without you needing to do anything. Plants grow by themself. Then all deserts world-wide would become green again, automatically. The problem is not "lack of water" in the deserts, no, the problem is lack of CO2 to enable plant growth. If there is 10x more CO2, then plants don't have to open their pores as much to breathe in enough CO2, so they don't evaporate and lose as much moisture. Then the current amount of water in the desert is sufficient. This has been proven over and over again in test-environments. And if all deserts would be green again, covered in forest, earth temperature would go down a bit and then stabilise. Because the sunlight is absorbed by the trees and turned into wood and leafs, so it is used-up, and can no longer heat the surface. Wood is stored solar energy. And if the whole earth would be green again, with 6...7x more plants than now, there is enough food for everyone, and for all animals. This would be very benificial too, obviously. The chemical formula is: CO2 + H2O + lots of sunlight-energy ---> long C-H-O chains (=wood + leafs + juices) + O2. In words: carbondioxide and water are turned into wood, leafs, and juices, if there is enough sunlight as energy source. And oxygen is released. This O2 is the oxygen we need to breath. So we do exactly the opposite as plants: we eat green (vegetables, fruits, wheat, nuts,...; thus we eat stored solar energy) and we breathe oxygen in. Out of these we produce energy to move and to keep our body on temperature. And we exhaust CO2 and H2O. So, solar energy is first stored in plants, and then we eat these plants to release that solar energy in our body. We are running on "indirect solar energy". Any process that consumes oil, or gass, and that produces CO2, greatly helps the growth of trees and plants. CO2 is the most important life-gas on earth, without which no life would be possible. So, don't feel bad when you need to burn oil, gas or plastic. As long as you burn it cleanly, without producing too much sooth and particles. You are greening the planet and improving life. Long ago, the whole earth was covered in green. But bit by bit, the leafs felt on the ground, and all this carbon got entrapped underground, in the form of coal, brown coal, oil and gas. So it could no longer be part of the life cycle. Today there is not enough carbon in the life-cycle anymore, on the earth surface, so life is dying. We should dig up all this entrapped carbon (coal, oil, gas,...), and burn it so it can be part of the life-cycle again. And so that we can make the whole earth green again. We need to produce way more CO2 than we do now, to save plant life. Yes, I know that my vision is not "politically correct", but it is definitely and absolutely scientifically correct. Life is dying because of lack of CO2: there is only 0.03 to 0.04%. Below 0.02%, plant growth is no longer possible. We are at the lower edge: plants are in continuous CO2-hunger, and we need to dramatically increase CO2 output to survive. You can easily search for, and verify these things. This is basic high-school science. And you can verify it in every greenhouse. So, clearly, plastic is a very good product, even if not perfect. As long as you don't throw it in the environment or in the sea. But you should or recycle it, or cleanly burn it to regain its energy. Don't feel bad for using plastic, and for burning gas and oil. Don't feel bad for improving plant life and saving the earth.

You will have to do that in a 3D-CAD program. Cura is a slicer, not a 3D-editor.

I have no solution for a smooth bottom plate on top of supports, for a single-nozzle printer (like my UM2). The underside where the support was, is always a bit rough. Except design changes: cutting the model in half, printing both halves on their flat cut side, and glueing both parts together afterwards. But you will see the seam. Or making the model asymmetrical, so that one side can be laid flat on the glass without need of support (if the design or function allows this). I once made testpieces for supports to try to minimize this roughness, and still be able to get the support off. A custom support with ribs gave the best result, but some roughness is still there. (See pic below: the numbers indicate the vertical gap in mm between the support ribs and the underside of the top plate. The ribs are 0.5mm, separated 1mm.) For testing, I recommend making a design with only the features under test, for example when testing the clamps, only print these clamps without the rest. Until you get this perfect. Idem for the supports: make a small test plate with just that. So you don't waste too much material and time.