Prusa Mk3s From excellent prints to rubbish.....
Has anybody seen printing like this before. My printer was working absolutely fine then I printed an object which finished leaving about 1mm of filament before the detector. Then I started another print not noticing and got a jam. I've cleared the jam BUT cannot get the printer to print well anymore. This is the kind of effect I'm getting. It looks like it is FAR too hot and melting everything but I've not changed anything. Both fans are working and it happens with Prusament and Amazon basic filament (I have a couple of rolls for doing test prints).
I'm also having problems with adhesion..... I wash the plate in soapy water regularly AND use IPA and acetone (IPA almost every print and Acetone rarely)
RE: Prusa Mk3s From excellent prints to rubbish.....
Clean bed with dish soap, a few times, and no alcohol.
Make your first layer 100% good.
These 2 are very important, if you print for longer times, months or years, people think it will work without adjusting settings.
Then make a first layer picture so we can look if it is OK. If it is OK then the print will work.
Check if you have a partial clog by extruding by hand , look if stream ia straight and thick enough, and does not bubble.
Every print you need to check the first line(s) and adjust if needed, then wen first layer is ready check if is OK, no white spot were it is releasing, or to low or to high(gabs in it).
In picture it looks like it has a wave in it, possible to low or to much filament.
Check thickness of filament.
A big flat model I would clean at highest standard, and use glue stick so it does not shrinks in a corner.
Tip for your plat model and a lot of holes, make the holes at the top close, then the printer will make of the top one big flat piece of model, and make it good flat.
General how I work:
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.
RE: Prusa Mk3s From excellent prints to rubbish.....
Peter,
Thank you for a very long and detailed answer. I built the printer 18 months ago and the plate is probably getting tired now. I wash it is soapy water at least once a week and use IPA very regularly. I try not to use acetone too often as it eats everything.
I print a LOT of flat plates as I use them to print for front panels. I'm not sure I have the filament tension right as when I got the jam I just undid it cleaned it all out and then screwed it back together. When the printer jammed it was squirting the filament into a giant round ball of hot plastic! I'm not sure it has been the same since...... I was holding on for the XL printer then I was going to strip the i3, clean it all and fully rebuild it.
I'd also noticed that my options were set to 10% in fill and lowest quality!
Even though I've been getting excellent prints I'm still not completely happy I know how to adjust the Z I just kept changing it till it printed really well and left it alone.
I'm currently re-printing that panel with the tension of the filament adjusted, 30% in fill and medium quality..... I will post the result as soon as it finishes.
RE: Prusa Mk3s From excellent prints to rubbish.....
They say it's always a good idea to do one of those Z calibration prints every time something major has been done or has happened to the extruder, and I would say that a significant jam is something major in this case.
It takes very little filament and very little time, particularly when compared to the time you would spend reprinting a failed print.
I would suggest letting the machine preheat and stabilize for a while, as in at least 10-15 minutes prior to the calibration print.
This print not only gives you a good picture of where your overall Z calibration is, any significant difference in the squares can be used to more closely dial in the factors you need to correct for an optimum first layer.
RE: Prusa Mk3s From excellent prints to rubbish.....
This is an image of layer 1 printed.
Is there a really good guide to redoing the Z?
RE: Prusa Mk3s From excellent prints to rubbish.....
Here's the original discussion started by the guy who introduced us to that 'my way' Z calibration print.
RE: Prusa Mk3s From excellent prints to rubbish.....
I've checked the tension of the filament which was ok and installed some prusament red.
Started first square at -0.885 which is what it happened to be and switched to -0.750 for the second half which is dramatically better just looking at the first 2-3 passes!!
RE: Prusa Mk3s From excellent prints to rubbish.....
OK that's done just doing another....
RE: Prusa Mk3s From excellent prints to rubbish.....
-0.885 is 0.13mm
-0.750 is 0.24mm
now working on -0.700
RE: Prusa Mk3s From excellent prints to rubbish.....
At 0.700 & 0.650 the print looks even more even but the strands are not connected as well (or in the case of the 650 at all!)
-0.700 @ 0.27mm
-0.650 @ 0.30mm
RE: Prusa Mk3s From excellent prints to rubbish.....
The test prints are being printed at 55 degrees for the bed. Is that considered better? I was using 60.
720 is much like 700
730 is closer to 750
770 is better and the winner 800 ! I think....
RE: Prusa Mk3s From excellent prints to rubbish.....
Thanks everyone, just trying to re-print the panel I was having issues with