I just wanted to share this in a separate post. If you were already involved in this, it’s nothing new. Anyway, I was having issues with blobs on my prints and couldn’t figure out how to get them to go away. I tried retraction settings, coasting, print speed, Z alignment and whatever else you can think of. What FINALLY worked was increasing the temperature of the hot end. I watched the nozzel really closely to see WHEN the blobing was occuring and it would happen right after it printed and right before it retracted. For a very brief period of time the print head wouldn’t be moving and would leave a blob, even with coasting on. This told me that there was still pressure in the nozzel and more plastic was still being pushed out before the filament was retracted. I then thought, “how do I release the extra pressure?” Well if I heat the plastic up a little more, it’ll be softer and easier to come out. If more is allowed to come out, there won’t be as much back pressure. So I raised the temp 5c and now it came out like this! Much smoother. This part is only 1" in diameter so it’s pretty small.
I’m printing with PLA+ from eSun. So far I’m pretty happy with the plastic. Nozzel temp is 205c (now). Bed temp is 65c. 60mm/s print speed. Coasting is on. I’m much more happy with these results vs what it’s been doing for a while now…
Here’s the old print with blobs.
I believe the hotter temp caused the retraction to work better, instead of stretching the filament, it was able to pull it back in to the heater block to relieve pressure, but I could be wrong.
Most of the time these bumps are fixed through retraction, but that might not be your case.
You can try a test and turn retraction distance & speed down, stop coasting, I bet the blobs would come back.
@PrintinAddiction I tried changing retracting settings all the way to 6mm and stopped because I was getting jams. This is currently at 4mm with a bowden tube setup. I definitely understand what you’re saying but I don’t think that’s the issue I had as the blobs were occuring BEFORE the retraction was evening happening. As soon as the printer stopped to retract, you could see the plastic ooze out before the retraction occurred.
@Kevin_Danger_Powers I have a print that I couldnt get all of the bumps resolved, I just chalked it up to tempermental filament, but I should retry it changing the temp.
missing/deleted image from Google+
@PrintinAddiction I think it was a mix of temp and coasting that helped this print. But like others have said, it could be a retraction issue as well. It just depends on what’s the underlying reason for the blobs. If they are occuring at the beginning of a print, your priming distance could be too high. If it’s randomly placed in a line, could be over extrusion or temp issues. If it’s at the end of a print line like mine, temp and coasting could help.
