B_Terneyre

Do you have examples of parts where it would be necessary? Small or big pieces? Cylindrical, square or oblong geometries, etc...? From what I understand, the main point of a support is to "carry" the higher angles of overhangs during printing, so I don't really see in which cases I would need a horizontal expansion

Thanks for the tip, lowering the horizontal expansion to 0mm actually removes all the vertical unnecessary supports, so I guess we won't need to customize our own support in this case. Although I have to ask: is this recommended? I understand that a higher horizontal expansion makes the support sturdier, but is it necessary on parts that already support themselves?

Hi, My company has recently bought an UM3 and used its dual extrusion abilities extensively, but the auto-generated supports in Cura have been curious to say the least. Here are the parts we have been printing: These were developped on Solidworks and dragged in Cura as .STL files. They are perfectly symmetrical, (as in, I have used the mirror functions on Solidworks, which means that each time I modify the original file, the mirrored piece updates automatically to remain symmetrical) but the supports in Cura are not: Front: Back: Left: Right: Cura generates supports on what are essentially vertical walls, i.e. some of the corners of the piece on the front view, and on a part of the exterior wall, but only on the piece on the right, oddly enough. We are using Cura 4.3 and default support parameters. We have tried to tweak some of the parameters but the only significant changes come when modifying the overhang angle. The pictures you see are with said angle set to 45°, we do not want to increase it because we want to keep it on the essential parts, and lowering it adds even more unnecessary support on vertical walls. Point is, we are not satisfied with the automatic supports on Cura and we would like to create custom supports to not waste printing time and material. We want to make our own supports on our CAD design, but we also want the support to be in PVA. Is there any way to assign different materials to specific parts of the same model on Cura, or should we make a separate .STL file for the support and merge it with our piece on Cura?

Thanks for the tip, but how do I integrate the custom supports/brims in Cura? Should I make a separate file for the support in Solidworks and merge it with my part in Cura? Making the support in the same STL file does not allow me to use separate materials for the part and the support.

Thank you for your answers. We are using Cura 4.3, which I believe is the latest version. We wanted to use a raft to correct the warping issues we have had with some of our parts, since rafts supposedly give you a better adhesion than a brim. Why are rafts so unusual on Ultimaker as you say? Does the printing quality of the UM3 make their use a bit of an overkill or is there a parameter we are missing? We checked the default raft air gap on Cura and it is indeed higher than zero (although why is that the case? I understand the need for the raft to not be completely fused with the piece to take it off easily once the print is finished but how can the raft attach itself to the part if we essentially ask the printer to print in the air?). We will try to set it to zero on our next print. I unfortunately have no picture to show you yet since we dicarded our failed prints. On a final note, we think we will continue using active levelling since it always seem to work well for us in spite of the hanging bits, although it would make more sense for the next version of Cura to heat the print cores after the active levelling to suppress this issue, if I may be so bold.

Hi Our company has recently aquired an Ultimaker 3, and my colleague and I have been tasked to experiment with it. We are new to 3D printing, so up to this point we have been experimenting with trial and error, tutorials and this forum to solve the various issues we have encountered. However, there are two problems for which we have not yet found a solution or a topic on this forum. The first issue is with our CPE rafts: our parts require supports to be printed, so we have used the dual extrusion features of the Ultimaker 3 to print PVA supports. So far this has worked weel with our PLA and CPE parts printed with brims, but we wanted to experiment with rafts. However, while the CPE raft itself is always well printed, the first layer of PVA does not stick to the raft, resulting in the support not being printed and a PVA blob accumulates around the nozzle, messing up the entire print. We are unsure if the issue stems from the material combination of CPE/PVA (which would be strange, since the materials are supposed to be compatible, plus our PVA supports work very well with our CPE parts when we use brims) or from our printing parameters. Again, this would seem odd since for the most part, we have used default parameters of Cura, with two exceptions: -We have lowered our CPE printing temperature from 240°C to 230°C, this has helped us solve our stringing issues, and is still within the recommended temperature range for CPE. -We have increased our glass plate temperature from 70°C to 80°C. Again, this has helped us solve our plate adhesion and warping issues while remaining in the recommended range (We use DimaFix adhesive spray for the plate adhesion, which works better on higher temperatures). But the PVA is printed on the raft, so the higher bed temperature should not be an issue. Besides, our PVA supports come out well when we print with brims, where the support is in direct contact with the 80°C plate. Since we have run out of PLA, we are unsure if our problem is unique to a CPE/PVA combination on rafts, or if supports are not meant to be printed on rafts in the first place. We have had the exact same issue when we have tried to print a PVA raft: the first layer of CPE would not stick to it. Our second problem is much less critical, but we have not found a solution either: each time we launch a print, a little bit of material extrudes from the nozzle during active leveling. Our parts still come out well, so it obviously does not affect the leveling process that much, but still leaves several bits of material hanging on the plate or sticking to the side of the nozzles. Is there any way to make sure the print cores heat after each active levelling? Thank you for any help you may provide.