Blob Panic Stop Option?
Hi,
I am experiencing a lot of problems with blobs. I only have the printer for some weeks now, but at least 50% of my prints seems to end in a partial print and a blob. Once you see the blob forming, the first thing you want is to keep the extruder temperature at the same value (or 10 degrees higher) and the extruder to home in de top position so you can reach it to pull it off.
To my frustration there is no stop / abort / panic option that does this. If you pause, the head will stay low on the print/bed, and then you need to stop the print (system cools down) then go into settings to move the z axis..
Am I the first one to look for something like this or is it somewhere in the system and I failed to find it?
Thanks,
RE: Blob Panic Stop Option?
I am not aware of any such option.
If I get a Blob,
I select 'Stop Print'
Then confirm 'Yes'
This stops the print and raises the extruder a little.
Then I select Preheat ASA and set the extruder heating.
I then press and Hold, the LCD Control knob, to access the Z axis height adjustment tool, and raise the X axis to a height where I can easily work on the extruder.
then I generally access the Settings >Temperature>Bed Menu and turn the heatbed off (0C)
then whilst I wait for the filament to heat and hopefully fall off, I look for a sheet of paper or card, my Soldering iron and my Brass Brush.
the paper goes on top of the Build plate, to catch any droppings.
the soldering iron (preferably temperature controlled) is used to carve off larger chunks of BLOB, if it is a big blob.
Pay attention to the heater and thermistor wires, these are often damaged during Blob Removal
It is often a good idea to remove your Part Fan Shroud to prevent further damage and gain access to more of the blob...
after I have removed the Bulk of the Blob, I use a tissue or cloth to wipe off as much molten grot as possible, an then use the wire brush to remove the rest... (Being VERY careful not to short out the heater wires or the thermistor wires. )
Once the Blob is removed,
Replace the Fan shroud, and remove all of the rubbish ( the sheet of paper should have caught most of the rubbish)
Next address the reason for loss of adhesion on the build plate
I Wash my build plate really vigorously using dish soap, Hot Water and a clean kitchen sponge, then Rinse well with Hot Water, and dry immediately with Plain Paper towels. 
Handle only by the edges of the build plate to prevent finger prints polluting the build plate surface,
If you are not already using it, use the 7x7 Mesh Bed Levelling Option, off the LCD Menu.
And I use the "Life Adjust 'Z' My Way" process, to sort the Live Z adjustment.
forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/
there is a link to a zip file, containing test print Gcode, at the bottom of the first Post on Page one of the thread
the middle panel of this poster, gives you an idea what is happening when you adjust Live Z,
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Blob Panic Stop Option?
Blobs normally happen if your filament is not sticking enough.
-bed needs to be 100% clean,
- first layer needs to be 100%.
Both settings need to be set good , this wil avoid the blob.
general setting:
A new sheet will stick less then a used one.
PLA sticks more difficult on a powder coated sheet. Is still possible settings need to be more preciese.
This how I work on a pei sheet(there are always exceptions):
Most important to 3d printing is:
1. 3d print will never be like start and i have the print, there will always be problems!!!!!!
2. A clean sheet, use dish soap, then you can print on it. A few prints you can use alcohol, then again dish soap,
big flat models and models with small footprint on sheet- use glue stick(and not every glue stick is the same,
use one that makes a thin layer), and big flat models and small footprint, use a big brim attach to model so footprint is bigger.
Petg sticks to much on the pei sheet, use window cleaner, this leaves a layer on the bed, so it does not stick to much.
3. To get it stick very good, a 100% first layer is very important, see youtube for movie on this.
Every new print watch the first layer, and look if it is 100%, this will also prevent a big ball of filament on your nozzle wen model let loose during printing.
Extra: (normally not needed).
First layer, print hotter.
First layer slower.
Bed more heat.
Most problems are first layer to get this 100%, and bed not clean.
Bad filament is possible, or filament with water inside.
Move extruder to the top and extrude filament, it should go straight down(if not, nozzle possible blocked),
it should be thick enough(if not, nozzle possible blocked, or partial blocked), (do a cold pull),
if Bubbling during extrusion then it has to much water inside.
Check after the first layer is ready, then you see if it sticking enough, and not releasing and sticking to the nozzle.
If you see white spots like a bubble on the bed, then filament is releasing from bed.
Also no gabs between lines should be visible.
Use 7x7 calibration for first layer, see settings in the printer.
Search for " 3D printer first layer problem Calibration process" on youtube, movie on first layer calibration, with a good zoom in.