Different Prints Failing at the Exact Same Height
The printer was printing fine for weeks until it crashed into a print. I inspected and recalibrated then ran a Benchy to test and it fails at the exact same height. After making sure the nozzle was fully seated, checking the pinda height and inspecting for obstructions I tried another benchy and got the same results on the exact same height. The Z screws are straight and not touching the top plastic parts. It prints perfectly up to a specific height then knocks the print off the bed. No idea where to go from here. I'm using PLA on an MK3+. Any thoughts would be appreciated!
I haven't printed a benchy and watched at the exact time it crashes but I do know it knocks the print off the bed. Tomorrow I can reprint a benchy and film the exact moment of impact if that would help.
Please show us the underside of a failed print.
Cheerio,
RE: Different Prints Failing at the Exact Same Height
Here's a look at the first layer. The print quality is good up to the fail point.
That looks slightly odd. The first layer is going down well but - what is causing that splatter pattern of discolouration? It it poor adhesion due to something being spilt/sprayed nearby?
Try giving the print sheet a thorough clean, see if that's enough.
Cheerio,
RE: Different Prints Failing at the Exact Same Height
There's no obvious problem with the sheet but it has been in use for years. I'm trying a new print with a much newer sheet and cleaning with alcohol first. Cleaning with alcohol before every print is standard practice here.
Give it the dishwashing detergent and HOT water treatment in case some alcohol insoluble substance is involved.
Cheerio,
RE: Different Prints Failing at the Exact Same Height
This time I have a new sheet and switched disks just in case there was some sort of truncation or damage to the other disk. The attached video shows the exact moment of the crash. It happens in the exact same spot/height every time when printing a Benchy and if printing a different file it will do the same, crash at the exact same spot. I did two more Benchys and shot video of each and the failure occurs at precisely the same spot resulting in a broken column on the Benchey cabin. The only difference is with this old filament it snaps the column instead of unseating the whole Benchy due to the filament being brittle and having excellent adhesion. I've only included one of the two videos as the results are identical.
Movie
OK, the print fails when steep overhangs warp upwards into the nozzle path. This is probably a cooling issue.
First check your print fan, make sure it's clean without fragments of stringing tangling the hub. Next try increasing the fan output.
Cheerio,