Problems with tall prints
I've been happily printing with my MINI for a year or two, but recently it has developed really odd issues with tall prints.
Most tallish (>1 inch) prints fail, with the print fading out in a way the looks like a clogged nozzle. However, if I remove the filament, clip off the ground down part and try again, it starts printing just fine, at least for the first inch or so. Some examples:
Short prints, even if they take a long time like this two hour plate of paracord winders are just fine.
Finally, I decided to a simple cylinder, which took and hour and finished but had terrible quality after about half an inch or so.
I don't think it's a clog, I've tried several cold pulls, cleaning filament and can get it to produce plenty of spaghetti without a problem. And I don't thing it's heat creep, because a long print that stays short also works great. Any ideas?
This is almost certain to be a first layer adhesion problem. There are hundreds of threads here about Z calibration and print sheet cleaning, go take a look.
Cheerio,
RE:
It's definitely not first layer adhesion, the prints are rock solid on the sheet with a great looking first layer.
RE: Problems with tall prints
RE: Problems with tall prints
clip off the ground down
How ground down? May point to an issue with the tension on the idler screw. Why that would manifest only at certain Z heights, escapes me.
I would also check my filament path to make sure there are no obstructions that may happen as the x-axis moves up. If there's a kink in the Bowden tube or the feeder tube from the spool, it may impede the filament's ability to reach the nozzle.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
Can you show us a picture of the whole printer as currently set up?
The Z axis doesn't usually suffer from loosened connectors or work hardened wiring failures but try moving from low to high Z (menu control) whilst lightly touching the carriage - does it move smoothly? If not, are snag points at predictable positions?
Cheerio,
RE: Problems with tall prints
Looks like it was, in fact a heat creep/PTFE tube issue. I swapped it out and was very careful about keeping the tube pushed up while tightening the grub screws seems to have fixed it.