Bump on cylinder print
When a print a round object, I get a bump on them. This simple hollow cylinder has it on the inside and outside. What is causing that?
$fn=128;difference(){cylinder(h=50,d=50,center=true);cylinder(h=51,d=40,center=true); }
Printed a 50% as I just needed a small one.
It's your seam, the point at which the printer changes layer(s).
Cheerio,
RE: Bump on cylinder print
Print settings, "Advanced", "Seam position": Change to e.g. "Random". This gives many random little dots on the surface (seam needs to go somewhere).
RE: Bump on cylinder print
Thanks. I will give that a try. Also checked the belts and found them a bit loose
RE: Bump on cylinder print
This comes up at least once a month…
I don't use ChatGPT much at all but for the fun of it I tried it, uploaded the photo and asked "what is the line in this photo". Here's the results.
The line visible in your photo appears to be a Z-seam (also known as a layer start or layer change seam) on a 3D-printed object.
Here’s what’s happening:
During FDM printing, each layer must start and end somewhere.
The printer extrudes filament in a continuous path, but when it finishes one layer and begins the next, there’s a small shift or overlap where extrusion starts and stops.
This creates a visible vertical line or ridge along the side of the print — the Z-seam.
Depending on your slicer and settings, the seam can be more or less noticeable.
You can reduce or hide it by:
Changing the Z-seam alignment (e.g., “random,” “rear,” or “aligned”) in your slicer settings.
Enabling “coast before retract” or “wipe while retracting” to minimize oozing.
Adjusting retraction distance and speed to control filament pressure at layer changes.
Lowering print temperature slightly if you’re seeing excess material buildup.
Would you like me to tell you how to tune these specifically in PrusaSlicer or another slicer?
Formerly known on this forum as @fuchsr -- https://foxrun3d.com/