First Prints - Blobs Issue

Jay_Cee · July 21, 2015

Hi All, looking forward to becoming active member of community. I received my ultimaker yesterday and have been impressed by its usability.

However, I have unfortunately had a lot of issues with my initial prints. I’ve successfully completed one print but 10+ others have ended like the version attached. Essentially the nozzle gets stuck midway through the print and creates this blob type of plastic.

The successful print involved adjusting the build plate, reducing speed to 50% and increasing temp to 230 with PLA.

Why do you think I am experiencing this? I think maybe my build plate is wrong because it seems to occur because of inaccuracy in the print layers. I.e. multiple imbalances adding up over time which mean that some way through the print it ‘catches’ an existing layer and gets stuck there? Am sure this is counter intuitive and is making problem worse but I tried moving nozzle further from the build plate thinking it was ‘too close’ but this increases the inaccuracy and imbalances I guess.

I got concerned that this would clog the nozzle but did the atomic method this morning and all seems fine.

Other relevant comments are that after every failed print I have to reload the material because it looks like this:

And there is some slight grinding on the filament. Is this to be expected.

Am I good to focus on recalibrating build plate or should I be thinking about anything else to reduce this issue. I was surprised that I couldn’t find examples of others experiencing the same thing. Thanks in advance!

gr5 · July 21, 2015

The leveling procedure only gets you so far. It's time to stop doing it and just turn the screws.

What's happening is your nozzle is too far from the glass. The bottom layer is almost cold before it touches the glass and barely sticking. At some point the part comes loose from the glass and gets dragged around by the nozzle and the filament keeps coming out in a big blob.

The fix is to first make sure your glass is at 50C to 60C (no cooler, no hotter). But the main problem is that you need to loosen the 3 leveling screws by the same amount. About a full turn. Just turn all 3 counter clockwise as seen from below right now. Then start a new print and watch the initial traces being laid down. If they aren't pushed flat like a pancake then loosen by a 1/4 turn WHILE IT'S PRINTING. Turn all 3 the same amount because you probably levelled it pretty well. Although if one side is more squished or less then you could do it accordingly. If you get confused about which way to turn don't panic - take your time. You may have to restart the print but so what.