I’m having a real bad issue with these raised bumps forming on the top layers of my last few prints.
It’s like the air trapped inside was too hot and started to melt it or something.
With this one I tried opening up the printer to let it cool during the last 2 hours. After I was sure it wouldn’t lift any.
Any advice would be appreciated.
More infill or more solid layers on top. You can also widen the extrusion width a bit.
I can’t adjust top layers specifically with my machine, and the final product needs to be as light as possible so I’m wary to adjust infill too much. But I guess I could try adding an extra shell.
But that’s a band aid, I’m more interested in figuring out what’s causing it currently.
Another thing I’ve noticed is that they tend to appear in the same general areas every time…
If you can’t adjust “top layers” with your machine, can you adjust anything called “shell thickness”? It’s not always the same name, but there are generally other settings you can adjust to achieve the same effect.
Yeah I know what shells are, and i can adjust them, but that also refers to the bottom and sides. Not specifically the top. Thus the confusion.
Well, what’s causing it is the filament is hot enough to allow it to droop across the lines of infill. As the nozzle crosses the infill lines, it can occasionally bunch the filament up in a tiny glob. You can try printing a little cooler, adding a fan, increasing shell thickness – often times there are a lot of different solutions for the same problem.
Have you tried to calibrate your temp for you filament?
Yeah I’m thinking the default temp for my printer is too high. Dremel proprietary filament prints at 220°. I just checked and this hatchbox filament’s max range is 210°. I actually tried lowering it by 5° for this file and it appears to be WORSE than on my previous project.
The issue I’m facing now is that I forgot to save my build platform before converting the files to .gdrem and I had to do a lot of tweaking to get them precisely the right size. I can’t remember how I got them there so I can’t duplicate it. If I redo the file I need to completely restart the project and I might not have enough filament at this point. Ug…
I’ll just keep trying to drop the temp when the print reaches half way. I have to seal up vents to compensate for the fact I removed the top plate to make room for my spool rack. I can open them back up and point a fan into it or something.
Be careful dropping the temp to fix that. More likely than not you will get poor layer adhesion and delam before you get a smooth top layer if you don’t increase the top shell thickness and/or infill.
Be sure your bed is nice and level, and that the offset is set correctly. Could be a dragging nozzle+temp
I’ve seen this with HIPS filament, though I didn’t know it was HIPS at the time because it was sold as ABS. But this doesn’t look like HIPS.
Anyway, bridging over infill breaks, leaving a hole that the next layer has a hard time bridging also. Have you been watching the part as it’s built? I think you want to try playing with speeds and temperatures as it’s trying to build the capping layers.
Again I can’t really adjust the file now because I wouldn’t have enough filament to finish the project. But I’m gonna contact Dremel tomorrow and ask if they know how to open up the .gdrem file to at least adjust the temperature down to 210.
If they can’t, I’ll try a small table fan set to low and pointed into the printer from a few feet away.
@Sphider_Web_Design yeah they seem to be in the same spot typically. With the occasional one popping up randomly.
It’s dremel. It’s even more closed source
This is the first project I’ve ever had this issue with. It’s normally a great machine. I was able to print this the day I bought it…
Can you increase infill at least?
Not without having to completely redo the process. I’m not an expert, but I’d imagine that any change in t the extruder movement would cause that.
So at this point there is nothing really left to do but start trying things. Theoretical goes out the window when you try it sometimes. My suggestion is to start trying what has been suggested and get some more filament on order.
