I’m glad there are experienced 3Deepers on this board.
Being a senior systems technologist, I can usually grapple a new technology quickly. But the SN2 is my first FDM and I’m baffled. I think I’ve got the recipe down, and the very next time I get a fail. The print doesn’t stick or the print embeds itself into the sticker. Blue tape peels off at temperature. Or nothing extrudes. Or unloading the filament breaks off at ¼" behind the nozzle.
I think what would help me at the moment is a step by step recipe on how to:
end the print correctly. Shut it off and let it cool down? Let it cool down and then shut off?
to unload correctly so the nozzle is clear
to start the print so the filament comes out correctly
to end the print so the filament comes out correctly the NEXT print
I don’t see that kind of precision, so maybe I missed it. I been a’lookin.
Those aren’t my only questions, but they’ll do for now. Thank you.
Sounds like a lot of your problem may be setting your z-offset too close.That’s when you’ll have problems or tend to get clogs.
Share some pictures of your first layer so we can see.
What kind of tape you uses matters. The cheap 3M is the best. The better stuff for painting that promises super clean lines for painting (with the green or orange printing on it) actually works the worst for 3D printing.
I don’t use tape though, I use gluestick if I’m going to use anything.(usually just with PETG)
Shouldn’t need to do anything. Print will release better if bed is warm, but usually releases fine either way if you’ve got correct first layer. It should be automatically turning off bed and nozzle at end of print.
Doesn’t really matter usually if you’re using same type of filament. Some people care more when changing types. Just heat nozzle to temp for old filament and unload. Pull on the filament until it releases from gear and comes out. Set nozzle temp for new filament and load. Might need to load a couple times until only new color comes out.
I like doing a 3 layer skirt. (if you’re using raft or brim doesn’t matter) That way it ‘primes’ the nozzle and you can see how stuff is coming out. Also makes easier to remove after done.
Don’t do anything. Depending on your humidity you might want to store your filament if not printing for a while.
I also guess your biggest challenge is the z-offset, additional to this you have a bad spool of filament.
I have a old spool of filament which easily breaks. This could also occure if the filament is wet.
One more thing, where sits your spool? - Could it easily fed to the print head? Too much force at the feed gear could cause filament grinding which means broken filament at the gear. The same issue could come from too much long retraction moves.
My filament enters the enclosure directly over the print head. The spool rides on two carriages on bearings.
I’m going to order a spool of white from each of two recommended companies and go another round of testing. I’m glad I have the bag full of extra nozzles.
And I’m still looking for a good way to clean out a nozzle full of filament.
I’ll have to go back and check but the filament will be Hatchbox and whatever Moosejuice recommended. (Bartender, I’ll have whatever he’s having.)
I’ve not found a cure for the ¼" of filament, and will just be aware, if I ever get it working completely.
The last issue I’m having is that the first two prints seem to work ok, but the filament gets cooked in the nozzle.
When a job starts from the cold, the nozzle and bed start to heat at the same time.
I think what’s happening is the nozzle heats up faster than the bed. I’m going to start manually heating the bed and then start the print. That way the heated filament isn’t sitting in a heated nozzle, getting cooked.
Is there a way to do this automatically, as a default? Heat up the bed and then start the print?
That is what I have been doing as well (same position - new to FDM and SM as of mid-Feb).
I switched to using Cura and have had much better results using that. Many forum users have provided their A350 machine profiles for Cura, and these include the initialization G-code which will set the bed temp first, wait for the bed temp, then set and wait for the nozzle temp. I found it speeds things up if you use the Control app on the touchscreen to start heating the bed while mucking about with the print in Cura.
I have only clogged one nozzle with filament and have not bother unclogging it - they are so cheap, I have not bother yet. If I intended to, i would put it back on the print head, heat the print head to 250, and keep attempting to load/feed PLA until is works through.
Like you said, you can achieve this in Cura with start gcode, but it might be worth preheating the bed anyways to make sure the entire bed is as close to the same temperature as possible. I find this can be significant in prints that use a lot of the bed, especially with the A350, but might not be as important with smaller prints.