Originally shared by René Jurack
Definitively worth a read, if you are into 3d-printing: http://my3dmatter.com/influence-infill-layer-height-pattern/
Thanks, very handy research.
An outstanding find! Thanks for sharing.
Strength test was purely tension? Well it’s not surprising that it’s pretty much proportional to infill then. Bending moment would be far more interesting (and useful).
@David_McGuigan Bending strength is almost entirely determined by perimeter count, infill does very little.
@Ryan_Carlyle that sounds fair on the face of it, but it would help to have empirical testing data to show that this is actually the case.
I am particularly interested in what happens to bending strength at around 90% infill, in light of the unexpected drop in tensile strength from 90% to 100% infill.
@Paul_Gross I’m failure sure the 3DMatter findings around 90-100% fills are an artifact of their slicer calibration. They reported low print quality at 100% infill, which is an obvious sign they were over-extruding and had not calibrated extrusion volume correctly for their slicer (which appears to have been Makerbot Desktop).
Before anyone says “100% infill just doesn’t make good-looking prints” or whatever, the way you’re supposed to calibrate volume in Makerware/Desktop (and S3D, and Craftware, and FlashPrint) is printing 100% infill calibration cubes while varying extrusion multiplier until the print is as solid as it can be WHILE IT LOOKS GOOD, so I am very confident saying they didn’t do the correct extrusion volume calibration for a Makerbot.
They only measured pull strength. I don’t think pull strength defines perfectly the strength of a print. For example it will bias the infill type results greatly in the favor of linear infill.
@Daid_Braam Exactly, you really need to do four-point bending, shear, AND tension tests, in at lease three infill orientations, to get a good sense of the overall properties.
Another issue no one has mentioned yet is that polymer failure data varies enormously with the rate the load is applied. PLA has vastly different elongation at break, UTS, etc depending on whether it’s a shock load or slow/creeping load.
Any idea what size nozzle they used? Id guess 0.4mm but it didnt say anywhere in the article that I could see.
Makerbot Replicator 5th Gen only comes with 0.4mm, as far as I’m aware. You CAN change the nozzle but very few people ever do.