kmil81

Thank you both for your help. Your info dialed in the outer dimensions for me almost immediately. It looks like the key for my inner dimensions appears to be playing with ranges of negative values for horizontal line expansion (and perhaps getting a smaller nozzle since I’m printing very small parts).

I’m relatively new to 3D printing and very new to Cura. I’ve modeled some components which have an inner dimension as well as an outer dimension (think a tube / cylinder with a hole in it. I’m finding that the dimensions I model in fusion 360 do not match what the printer is putting out. I suspect that it’s off by approximately half the wall thickness specified in Cura but haven’t conclusively determined if this is the case. What is the best practice for modeling and printing dimensionally accurate components? The two things I can think of are: 1. Dimension the part in fusion 360 with inner dimensions larger than desired and outer dimensions smaller than desired to account for wall thickness OR 2. There are some settings in Cura I don’t know about that will account for wall thickness to preserve the model dimensions. I’ve seen some posts saying that single walled (solid) models come out accurate but double walled (like what I’m trying to do) do not. For reference, I have an Ultimaker 3 using Ultimaker tough PLA for most of my prints. So what is the right approach to this? Address in the model? Address in Cura? Both? Thank you for your help!

What are your initial layer height and initial layer width set to relative to the primary layer height? If the initial layer height is too low or the initial layer width is too wide (or both), it will squish the first layer.

I was reading through all of the threads on bed adhesion because all was going well for me and then all of a sudden the brim and first layer would not stick. I discovered my issue and thought I would share in case it can help anyone else. The issue as it turns out was environmental, not the printer, filament, or the Cura settings. As it's hot right now, the air conditioning is going full blast and a ceiling fan is on low in the room. It looks like the AC vent got turned and the cold air was blowing down on the printer. As soon as I redirected the air and turned off the ceiling fan, all worked great again. I found that I'm able to turn it back on once the first layer is down. For reference this was using Ultimaker PLA on an Ultimaker 3. Ambient temperature 75f. All settings as default for UM PLA.

That's great news! Thank you for your help.

I have a new Ultimaker 3 and everything works great. I have had no issues with printing wirelessly from Cura 4.1 to the UM3. I have a noob question as I'm new to Cura and Ultimaker. My question is, does my PC have to stay on with Cura up the entire time the print is running or can I shut it down after the print starts? In other words, is the PC / Cura streaming g-code throughout the entire print or is it all sent at once and stored in the printer's memory and thus the PC is not needed after initializing the print?

Thank you so much for your help! I see that the settings tooltip mentions that this helps the printer avoid hitting the print when traveling. It sounds from your reply that this is not a risk on Ultimaker printers. Is that accurate? Would there ever be a case when I would need this to be on with the UM3 (dual filament prints perhaps)?

Forgot to mention, I'm printing using the silver Ultimaker PLA that came with the UM3. Attached is an example of one of my test prints. Most of the gaps have no stringing. It's only occurring when it does the bed drop and then raise behavior.

I'm the proud new owner of an Ultimaker 3. It is living up to the promise of being user friendly and reliable. This is my first experience with both Ultimaker and Cura. I have noticed one strange thing in some of my test prints. When the printer is traversing open space (from a point where it printed, over an area where there is no print, headed toward its next extrusion area), sometimes it heads straight over at the same height (in which case there is no stringing occurring) however, sometimes it quickly lowers and then raises back up (total travel is sub-second) the print bed leaving a string like you would expect to see at the end of a print. It feels random when it does it (as in it's not always at the end of a layer). The end of a layer does the very slight lowing of the platform to get to the next layer (as I would expect it to) rather than this more significant lower and then raise behavior. I've found the setting "Enable retraction" option in the Material section but this refers to retracting the filament when traveling over non-printed areas, not lowering the bed. I'm relatively new to 3D printing so reading g-code to figure out why it does this is not within my current capabilities. Does anyone know if there is a setting for this or a way to get it to stop this behavior? Thank you all for your help!