pbackx

Google 'hot pull' and 'cold pull' to clean the nozzle. If this keeps happening frequently after you clean the nozzle, you probably need to raise the printing temperature a bit.

Sorry I can't help you. I doubt this can be configured. There's a similar issue with the bottom layer that can be really visible with some of the more reflective filaments

I think that's the correct way to go about it. It was also the best solution I found when I wanted to change the active leveling distance slightly:

I can't really explain everything, but these look like extrusion issues. What you can try: * Clean the heads using hot and cold pull method * Check the temperatures at which you are printing. Maybe increase them a bit? * If printing PVA is making popping/hissing noises, it's probably because the PVA has absorbed too much moisture. Try to dry it on the build plate, or with another technique. Keep in mind: PVA is a very difficult material. You have to keep it in a bag as much as possible and not expose it to air for too long. On my UM3 I have the same problem as your 2nd print: when there's not much support to print and there's a lot of retraction, it will just clog up the nozzle. The only workaround I have found is to try to increase the amount of support material that is printed. For instance, enable a prime tower. What is the other (green) material? I haven't had any issues with PLA at all. It's just PVA that is giving me headaches.

In that case, it's maybe easier to print a raft?

I would guess that those are indeed infill, but since you already tried to change it, I'm not sure... There are a number of options you can try: Change your wall thickness and/or the number of shells until this effect disappears (it looks like you already tried it) Change infill pattern to circular Maybe this model is suitable for the spiralize mode?

Maybe another point of reference: PLA and PVA I print straight to the glass, nothing extra and no brim. I clean the glass plate fairly regularly. Usually just some random window cleaner I have. If the weather is good outside, I also use acetone, but hate to use this indoors because it smells awful. Bigger items may warp in the corners. For those I add a brim and sometimes hairspray or 3dlac. Afterwards, I just leave the hairspray on until the next cleaning (it has never interfered with the following prints, so why bother)

I don't print with Nylon, but I would guess it works similarly. I just put the role in a cardboard box on the heated bed. A proper dry box like @Ryan8696 would be even better, because you can keep printing while the filament is drying.

Yes, good idea ? I always put the PVA on my heated bed at 55°C for half an hour before I start printing. If it's been more than a day or two, I put it on there for at least 2 hours.

This may or may not answer your question. But if you can change the model, I would add a fillet around that cylinder: https://en.wikipedia.org/wiki/Fillet_(mechanics) In general, when designing models for 3D printing, you want to add fillets everywhere and probably also round all the corners a bit.

This is a great result. How did you manually slice that third color? Did you use the CuraEngine branch by Tim or some other trick?

Nice setup and thanks for the details. Always interesting to read those. Just a small practical question: How do you change filament on those UM3's in the middle of the rack? With the controls on the front and the feeder on the back this must require teamwork or acrobatics :)

Do both print in an equal time? Maybe the Cura one prints quicker, which could explain that the layers are not aligned as well.

I've never seen any other color, except for the harsh white, but you may be right. I haven't tried it. How to know what JSON to send? I don't think there is a good and reliable way, except to try it out. I thought you always needed to send JSON and in case of doubt, just use the parameter name that's mentioned in the docs. So it's weird to see an example that does it differently. Maybe this used to be different and they haven't updated the documentation?

With regards to the LED color, I don't think this is supported on the UM3. These LEDs can only produce white. The name change : you need to write correct JSON in the request. Something like { "name" :"Ultimaker3" } (sorry for my short response I 'm on my mobile. Let me know if you want me to elaborate)