What do you suppose causes this? I’m wondering if the filament is hanging up in the Bowden, then over extruding when it overcomes a restriction.
You may want to go see a doctor about possible STDs…
(Though, seriously - do you have “randomize starting points” checked in Slic3r? It might just be ooze.)
Your prediction sounds about right to me.
The points do look pretty random, not in a line up one edge anyway. Id tend to agree, i have small leakages with my bowden setup, managed to tweak my retract rate to get an acceptable finish. good luck
Some slicers randomize the start point. I would increase retraction distance if it’s less than 3, and maybe increase retraction accel and speed.
it’s 4mm each way at 40mm/sec…I’ve gone crazy high at 150-200 mm/sec and 6mm, but it really wasn’t happy doing so. I’d shorten the bowden, but I’m keeping the length for moving the e3dv5 to the next printer…which will have a MUCH more predictable bowden curvature.
I’d do 6mm@80-100mm/s, personally.
I have had these issues when temp was too low leading to high back pressure behind the orifice. Upping the temp made back pressure lower an the blobs went away. No other changes needed. This supprized me because I at first thought the blobs were from running PLA too hot. Might be worth a quick test.
Edit: Looking again the high shine on the part makes me think it might not be too cold. I only seem to get that sort of finish at high temps or really low speeds. But it might just be the filament.
I pulled the extruder of the tower of the printer and it’s held up high on a camera tripod to make the bowden as straight a run as possible. I need to print a couple of parts before they wear out on the Delta…Once the critical stuff is printed, I’ll retest for blobs.
(The above would appear to be Gibberish to someone from 2010.)
I know I am a little late to be adding to this conversation but I have noticed if you are doing anything else on your computer while printing you will get little micro pauses where the print head stops moving at random (due to the taxing nature of whatever else you are doing on you computer at that time) and leaves a blob because of pressure still in the bowden hose. So if you want a clean print just let the computer sit and print and nothing else. Honestly the best solution is to not use bowden hose, they have too many variables that can not be controled. I understand you are using a delta style printer and this is currently the only really viable option right now but soon I hope to change that.
You’re late, but it’s still a valid thing for people to consider. I’m my case, the printer is being fed by a Raspberry Pi and Octoprint, so I’m pretty sure it’s not a factor.