inverse elephant foot issue..
I am trying to use prusa slicer for my other printer as well, which is a folgertech FT-5. I am runnign the latest 2.2.0. This other printer has a .6 nozzle on it. This is the first time I am playing with a nozzle of this size, and my heater block can handle the extra flow.
I am having a very hard time getting the first few layers to print straight vertical shells or walls. My first layer height is .2 and subsequent layers are at .4 height.
If I print a 40mm X 40 mm cube with a 20mm square hole in the center, the first layer is not wide enough to meet 40mm and the inside hole is larger than 20mm. A few layers up the outside dimension of the cube is 41mm and the inside hole is now 18.5mm. So I cant use a simple XY scale. I feel that the permiter lay down is not calculated correctly, and is placed on the edge.
I have attached my latest config. I have been trying to get this to work for 2 days now, doing many test prints, and i cant seem to get this to stablize. I have checked my esteps on my extruder many times. The printer has an SKR 1.1 pro, with tmc2130 drivers, and all connected to octoprint.
I try changing some settings like the extrusion width in advanced print settings, and they dont always seem to change anything. Like an obvious one is external perimeters, if I set that to .3 .6 or even .8 no change happens on my prints.
Any help or guidance would be appreciated.
RE: inverse elephant foot issue..
Did not find a config attached. You have to zip up any files to upload and attach them here.
There is a setting under Print Settings->Advanced->Slicing->Elephant foot compensation, but it won't take negative values. It sounds like your 1st layer(s) is under-extruding. If you print a shape with a shelf on it (I've attached a sample) how do the walls look. Is the distortion only where solid layers transition to hollow walls or vice versa?
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He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: inverse elephant foot issue..
sorry that the files didnt post. I have elephant now set to zero, but the bigger problem that the rest of the layers were over extruding. I did change one setting which helped me a lot, and that is to lay down the external perimeters first. Once I made that setting, the walls are very vertical and the inside dimension is much closer, but not perfect. Its still a tiny bit small. I will do some tests with large and small objects with holes and see how i can adjust the xy size compensation slightly larger. thanks for your help @bobstro.
Jason
RE: inverse elephant foot issue..
If your normal layers are over extruding have you calibrated your extruder steps per mm ? Or checked your actual filament width using calipers and altered the filament settings to match ?
If you look in Bobs signature above you will see a link to his notes website. Its full of good stuff that should be read 🙂
RE: inverse elephant foot issue..
thanks for the info..i have checked my esteps many times today, did a full half meter extrude and it measured out perfectly. I will check out his site, but turning on perimeters first really helped me out. I also think i had my z accel waaay too high at 100, its a lead screw setup. I set that back to 10. Maybe it was skipping steps.
RE: inverse elephant foot issue..
Just had a look at what the MK3 uses for machine limits on Z, Max feedrate =12, Max Accel=1000, Max Jerk 0.4
My Cr10 profile has 100 for max Z accel though
RE: inverse elephant foot issue..
yea my FT-5 the original marlin 8 bit config file showed 10 as the max accell.. its a dual leadscrew system, im sure it can do more, but i think its fine at 10.