Hi All. I could use a little help adjusting my printer. This is my first plate of prints from a Prusa I3 8" using a 0.5mm nozzle with ABS. This is the recommended config from makerfarm (https://docs.google.com/file/d/0B80A_woXoRWdRFZ0LTFGSVdIOVU/edit?usp=sharing) except with heatbed at 110 (100 first layer) and heater at 205. All objects are printed at once, not sequentially.
The bottom 5 layers are mushrooming out. This is easiest to see on the cylinder but is present on all objects.
Should I increase the retraction to reduce the stringing between objects (currently 1mm)? I’m not sure if this is a reasonable amount of stringing.
The corners on the cube are lifting/curling, but this doesn’t seem to happen on the other objects. Does this only effect the cube because it is a larger solid? (I am currently using hairspray, but plan to try ABS slurry as well.)
I don’t understand why I would want the first layer heat bed temperature to be lower than the following layers (from the recommended configuration). If the problem is adhesion, wouldn’t I want the first layer to be hotter? Maybe this just allows the printing to start earlier because reaching 110 takes a while?
Makerfarm recommends slic3r version 0.9.9 rather than newer versions due to overextrusion. I assume that this is a bug in specific versions that may have been patched by now? Does anyone hare more info on this?
Thanks in advance. I know that additional trial and error could resolve these questions, but I’m itching to print something useful.
no stringing is definitely achievable - try increasing retraction to 4 or 5mm? And up the speed to maybe something around 40 (or more if it is bowden drive…)
Shape has a lot to do with warping / bed adhesion, but that shouldn’t peel. Try setting a slightly lower (or negative if necessary) z-offset to really get a smooshed first layer. With brim set to 0, slightly lower the offset until you feel the start of a brim on your part, then bring it up a hair (.01 or .02 mm?). This might help with issue 1?
I don’t know which bed temp should be hotter - initial or post printing. I keep it the same, as hot as is easily manageable for ABS on your rig. (I run my Mendel 90 at 130! Heats up quicker with the bigger driver on my Elefu RA control board.)
I hadn’t heard that about slic3r - I wonder if that’s contributing to a few of my over-extrusion problems. I’ll do a comparison slice and see.
@Anthony_White , adjusting the retention helped but did not entirely eliminate stringing. It sounds like the extruded is skipping steps, so I might be able to tune it further with some work.
What speeds are you printing at? Your hot end might be at to low a temperature - what kind are you using? Do you have your nozzle size set in slic3er’s extruder configuration? Is your extruder properly tensioned (I’m not familiar with makerfarms exruder but if you run filament and then back it out, you should have indentations in the filament)
@Anthony_White , I am mostly using the defaults from makerfarm for this printer which is 30, 60, 130 for permieter, infill, travel. .50 j-head. Slic3r printer settings match the hardware that I have. The extruder does mark but not chew up the filament.
I dropped the temperature from 225 to 205 after having the top layers of a cube cave in. Such a large step was accidental, but it really cleaned up the top.
Squishing the first layer more makes sense; there is slight texture between lines. I will try that now.
@Phil_Hord , the problem was not bridging. The fill was actually collapsing. Maybe the readings are off. I can try adjusting the placement of the thermister if you think that will help. Btw, I do not have a fan. Maybe that makes a difference on nozzle temp.
