Printed first test cube with flashforge creator pro, abs, with default abs settings on simplify3d. You can see in the pic, there are a lot of ridges from the layers, more pronounced on the corners. The size varies from top to bottom, the very bottom layer is big, then it gets small, and as you move to the top, it gets closer to 20, and at the top it’s 20.11. The top surface bulged a lot as you can see in the pic.
This was printed with 100% infill.
Note, the hole I drilled to see if the top layer was perhaps separating from the ones below, but it was solid.
What settings might I start with tweaking to improve the results?
You need to calibrate. Looks like you are extruding too much material into a space where it doesn’t fit. This could be x/y steps/mm, extruder steps/mm, y steps/mm, or perimeter/infill overlap.
I have a similar issue with the cube which is the extended layers or bumps on the corners. On mine the sides and top/bottom are good but I am getting the same pattern on the corner. S3D had me add a negative restart to the extrusion which helped but conversely it hurt in other areas such as small parts of a print which get under extruded.
Definitely looks like over extrusion. You might try backing off the extrusion multiplier a little at a time. I have mine at 100 for ABS and it does ok but that is default.
I don’t recommend trying to solve problems by messing with the extrusion multiplier. You need to calibrate your extruder. Mark the filament and when you tell it to feed 10mm of material does is move 10mm? If you try to fix this with the extrusion multiplier you are throwing off all the calculations of the slicer software and will get poor results.
-Jesse
You are overextruding. Start by measuring your filament with calipers, and make sure the width of the filament, which varies from vendor to vendor, is correct in s3d.
If you change that, run another test. (PS, you dont have to print that tall of a cube for each test. Shrink it on the z axis to about 25%, no need to print it so tall for your testing.)
Then, its extrusion multiplier time:
S3D has an auto setting, that sets it to 20% more than the extrusion nozzle diameter. This is because s3d assumes you will have that much back pressure in your extruder, thus it will expand that much when printed. Set it to manual, start at your extruder nozzle diameter (usually .4) and do a test print. It will probably underextrude. Slowly raise it by .02mm at a time, and run a test print. You will get to the correct extrusion multiplier for your printer, your nozzle, and your filament.
Once you get dialed in, you will be a happy camper.
Do you know of any guides published on this calibration method, or on the adjustments in the other comment you shared? If yes, could you link it here for the group?
Update from 9/18. My printer hung up on another job, as the spool for the 2nd extruder was a hack job. I found a thingiverse file to print a new spool. The results are not great, appear to have problems with bridging, warping, and weakness. File snapped in several places and I could pull apart stuff.
Here’s a link to the file, and what it should print like.
I respectfully disagree. The slicer assumes too much, and you have to help it. Extrusion multiplier is a common and oft suggested way to get your printer dialed in. Every printer and filament has different properties, so you have to get your slicer to a point where it is defined for your particular printer and filament.
“The slicer assumes too much, and you have to help it.”
The slicer assumes you have calibrated the steps/mm. That’s how you “help it”
“Extrusion multiplier is a common and oft suggested way to get your printer dialed in.”
Suggested by who? Crappy looking prints are also common.
“Every printer and filament has different properties, so you have to get your slicer to a point where it is defined for your particular printer and filament.”
Correct. This is done through calibration of the extruder and measuring the diameter of each filament.
I print a lot of materials and I’m constantly changing nozzles and cannot compromise on uniform dimensional accuracy. You might get your printer “dialed in” with your method but it will not be repeatable when changing other factors. There are certain circumstances where the extrusion multiplier is useful but this is not it.
Adjusting feed distance, extrusion multiplier, filament diameter all do the same thing. They’ll all produce the same results. The only thing the extruder can do is push more or less plastic through.
“Adjusting feed distance, extrusion multiplier, filament diameter all do the same thing.”
This is somewhat correct but misleading.
The slicer calculates the amount of material extruded(volume) based on steps/mm(calibration) and filament diameter(should be measured with a caliper). When these numbers are correct you don’t need to touch the extrusion multiplier.
If repeatable precision/dimensional accuracy when switching materials or nozzles is important then this shortcut is working against you. If your machine is calibrated, then switching material means inputting the new filament’s diameter and you are good to go. If you’re currently dialed in with the extrusion multiplier, then instead of inputting in the diameter of new filament you are playing the extrusion multiplier game every time because you are “dialed in” based on trial and error, not numbers.
