Here is a print that is running. In the circle I drew you can see what looks like a shift in the layer but I don’t really think it is. It is right where the base of the item sops and the sides start to build up. Is this uneven cooling or something? I know about the corners lifting but I am concerned about the area above that.
This is a FFCP, Hatchbox ABS, Bed 110, extruder 225, 15% infill, enclosed case.
To me it seems like the first layers making up the base shrunk more than the higher parts. At first I thought the layers had split but it is not. Aside from this area the print is going nicely.
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If it is the same shrunken all the way around, it is uneven cooling. That is quite a bit of uneven cooling, but if this print is ABS, I suppose it is possible.
If it is shifted, it will be shifted in the same direction, meaning that it will intrude on on or two sides, and extrude on one or two sides.
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I thought it was excessive for ABS to shrink like this. I ran the heater until the cabinet temp stabilized before starting the print, it is running about 102 in the cabinet.
The bottom is 5mm thick with a 15% rectilinear infill 3 bottom layers and two shells. I did an attached brim that helped with the corner curling but I think I need to do more on that. I wondered if 225 was low but it seems to be printing nice other than that area.
This is still printing so once it is done I can look closer for a shift but I do not suspect it. The rest of the print is really nice.
Here are a few more shots on this. It appears to be shrink. What steps can I take to reduce or eliminate?
Wow, that is a lot of shrinkage for ABS.
A couple of things. Your bed should be 110.
You may be printing too hot, exasperating your shrinkage.
Is the filament cheap? (or what came with the printer?) Bad filament = bad prints.
Infill affects shrinkage.
Try helper disks to hold it down.
Make sure your fan is off.
You can try octagonal infill, which may help, but I doubt it.
Use the same %infill on the whole print.
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But again, I have never seen that much shrinkage.
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I’ll answer item by item!
Bed was set to 110, extruder 230. In the past I have dropped the bed temp to 100 after a few layers with ABS but I don’t know if that really helps or hurts.
Filament is Hatchbox ABS - new roll.
Infill 10-15% I think it was. Same fill - process settings for whole print. I think it was rectilinear.
I tried a small brim right on the print but realize I need some more width and maybe an extra layer.
Fan should have been off.
I was surprised by the warp also. The print was fine for a few hours then went nuts.
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Hey, I have the same printer, and same filament. I had the exact issue you are having now, and I found out that it was not being heated well enough. When I print with ABS, I make sure to use extra hairspray to hold the part down, print a 2 layer brim to anchor the corners and edges down, and before the print is started I close the door, completely seal the printer and let it heat up for like 20 minutes. What I do to insulate the printer is put a pillowcase around the top, and then tape cardboard to the holes on the side (see pic). That solved all the issues I had, go ahead and try that and see if it works for you.
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Mine’s a little newer and the sides are sealed. I could seal the top better but I need to fit the filament tubes and cable better. Still the top was on. I let it preheat until a thermometer inside was stable at 100c, probably 45 minutes. It maintained that temp throughout.
I know from experiment that I need to expand the brim, it was a last minute thought to stop the corners. They were good for a few hours then the whole thing started to go crazy.
Fortunately the part was fine in PLA. It’s a multi-meter holder to hang on the side of a tool box.
What did you use for temps and speed?
tabbott
9
I like to print abs hot and fast, so that the previous layer doesn’t have time to cool too much. I print at 240c and at 3800mm/min avg. speed and 4200mm/min x/y axis movement speed I keep the bed at 110 too
New ABS question. See the attached pic (sample). I am making a pipe clamp represented by the bottom part in the pic. Is it better to print this with the wide-large surface area on the bed or turn it upside-down so the minimal amount touches the bed? I did one with the large area on the bed and it did ok. I think I need more brim. Just wondering if it is better to have the large surface area on the bed or the smaller surface area on the bed?
tabbott
11
Read tip #4
I think this may be useful too
