Just finished getting my prusa up and running and trying to get some prints dialed in (using slic3r). I'm using 3mm filament (ABS) with a 0.35mm nozzle. It looks like for thicker layer heights, the perimeters are not adhering to the previous layer correctly. By bringing the layer down to 0.2mm (keeping everything else the same) I've managed to get what I'd consider a good print. (see attached image) It seems to happen on layers with sparse infill (solid top and bottom layers look fine). I think my steps/mm is dialed in pretty good (did a number of tests). My guess is that it is either 1. For thicker layer heights the extruder runs faster and occassionally strips. I've adjusted the idler tension and stepper current as high as I can and it doesn't seem to help. 2. Sparse layers are calculated differently? Do I need to force the extrusion width on the advanced tab? In the attached image, the prints are (left to right) 0.2mm, 0.25mm, 0.30mm. I'm able to get good prints at 0.3mm with the same nozzle (different extruder) on my cupcake (using skeinforge) so I know it's possible! https://reprap.org/forum/read.php?263,114104,114104#msg-114104 Fri, 10 Jul 2026 23:05:03 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?263,114104,117693#msg-117693 https://reprap.org/forum/read.php?263,114104,117693#msg-117693 tsb4k Slic3r Tue, 07 Feb 2012 23:10:13 -0500 https://reprap.org/forum/read.php?263,114104,116142#msg-116142 https://reprap.org/forum/read.php?263,114104,116142#msg-116142
If I extrude from pronterface it seems like I can see slight variations in the rotation speed of the extruder gears. Getting the idler tension and stepper driver current balanced has been a real problem for me.

Maybe I will try to swap over the geared stepper from my cupcake to see if this is the case.]]> tsb4k Slic3r Sat, 28 Jan 2012 13:55:26 -0500 https://reprap.org/forum/read.php?263,114104,115868#msg-115868 https://reprap.org/forum/read.php?263,114104,115868#msg-115868 -------------------------------------------------------
> What heat are you running?
> It looks like a heated bed, if so does you're
> power supply/s have enough power?

I believe so, I haven't seen any abnormal behaviour or shutdowns.
I will measure the 12V line during a print to see if it is sagging at all.]]> tsb4k Slic3r Fri, 27 Jan 2012 00:39:05 -0500 https://reprap.org/forum/read.php?263,114104,115862#msg-115862 https://reprap.org/forum/read.php?263,114104,115862#msg-115862 It looks like a heated bed, if so does you're power supply/s have enough power?]]> Gulf Slic3r Thu, 26 Jan 2012 22:35:52 -0500 https://reprap.org/forum/read.php?263,114104,115307#msg-115307 https://reprap.org/forum/read.php?263,114104,115307#msg-115307 -------------------------------------------------------
> Do you have z lift turned on? That is the only
> real way you could end up getting backlash in the
> z direction. Otherwise you are constantly moving
> in the same direction, so backlash would not rear
> it's ugly head.

I don't have lift enabled. I tried it once but had basically the same output.

Right now I'm trying to eliminate mechanical problems:
-Replaced printed idler pulleys with bearings + fender washers
-Tensioned all belts
-Re-leveled platform with the springs more tightly compressed

My next steps are:
-Test the extruder with another set of gears to make sure they aren't wonky (looking for periodic errors)
-Mount the heated bed pcb onto an aluminum or glass plate (I don't like the little bit of flex it has)]]> tsb4k Slic3r Mon, 23 Jan 2012 18:42:16 -0500 https://reprap.org/forum/read.php?263,114104,114581#msg-114581 https://reprap.org/forum/read.php?263,114104,114581#msg-114581 tinyenormous Slic3r Thu, 19 Jan 2012 09:29:52 -0500 https://reprap.org/forum/read.php?263,114104,114367#msg-114367 https://reprap.org/forum/read.php?263,114104,114367#msg-114367
I'm not being very systematic about this but my next hunch is the z-axis. Since the effect seems to go all the way around the affected layer (not just the beginning which I would expect if the filament was just lagging) I wonder if I have inconsistent layer height.

Now that I think about it, I didn't install the springs in the x-ends on the threaded rods..]]> tsb4k Slic3r Tue, 17 Jan 2012 22:57:02 -0500 https://reprap.org/forum/read.php?263,114104,114357#msg-114357 https://reprap.org/forum/read.php?263,114104,114357#msg-114357 Right now I have perimeters at 30mm/s and infill at 60mm/s. I'll try turning all the speeds down.]]> tsb4k Slic3r Tue, 17 Jan 2012 19:35:05 -0500 https://reprap.org/forum/read.php?263,114104,114259#msg-114259 https://reprap.org/forum/read.php?263,114104,114259#msg-114259
Are you trying to bridge faster than the solid infill speed?]]> richrap Slic3r Tue, 17 Jan 2012 05:53:47 -0500 https://reprap.org/forum/read.php?263,114104,114230#msg-114230 https://reprap.org/forum/read.php?263,114104,114230#msg-114230 -------------------------------------------------------
> More Heat !
>
>
>
>
> Michael

I tried bumping the temperature quite a bit and I'm still getting the same effect.
I should probably have posted this in the printing forum, I don't think it's a slic3r issue so much now.

I noticed that when it starts doing bridges the extruder can't keep up at first. The problem probably lies there (not with bridges but with the extruder)]]> tsb4k Slic3r Mon, 16 Jan 2012 23:01:13 -0500 https://reprap.org/forum/read.php?263,114104,114215#msg-114215 https://reprap.org/forum/read.php?263,114104,114215#msg-114215



Michael]]> Hardwarekiller Slic3r Mon, 16 Jan 2012 20:55:52 -0500 https://reprap.org/forum/read.php?263,114104,114104#msg-114104 https://reprap.org/forum/read.php?263,114104,114104#msg-114104 It looks like for thicker layer heights, the perimeters are not adhering to the previous layer correctly. By bringing the layer down to 0.2mm (keeping everything else the same) I've managed to get what I'd consider a good print. (see attached image) It seems to happen on layers with sparse infill (solid top and bottom layers look fine). I think my steps/mm is dialed in pretty good (did a number of tests).

My guess is that it is either
1. For thicker layer heights the extruder runs faster and occassionally strips. I've adjusted the idler tension and stepper current as high as I can and it doesn't seem to help.
2. Sparse layers are calculated differently? Do I need to force the extrusion width on the advanced tab?

In the attached image, the prints are (left to right) 0.2mm, 0.25mm, 0.30mm.

I'm able to get good prints at 0.3mm with the same nozzle (different extruder) on my cupcake (using skeinforge) so I know it's possible!]]> tsb4k Slic3r Sun, 15 Jan 2012 23:51:47 -0500