Slicer Comparison

Probably the most important step in 3D printing is the slicing- the conversion of a 3D mesh into a set of toolpaths for the extruder in the form of gcode.  There are several options for software to do this, and they will all create gcode a little differently, giving slightly different results for the same model.

I wanted to do a survey of a few different slicers and really get a definitive feel for how they differ.  My choices were-

Slic3r 0.9.7-, the latest version.  It was released after I started printing, so I also used-

Slic3r 0.9.5/6-  Though one release back from 097 there were distinct differences.  Slic3r is the most configurable of the slicers, at least in the settings that are more widely understood by printer users.  For instance you can set different speeds for outer perimeters, inner perimeters, small perimeters, infill, etc to find the balance between quality and speed.

Slic3r 0.7.2b- After this version, Slic3r had a total rewrite, which many consider a step back in quality.  Many users continue to use this version, though it lacks some of the newer features and is prone to running out of memory when slicing medium to large models at .1mm resolution.

Skeinforge 39- This is the version of Skeinforge that Solidoodle includes in their installation.  The biggest difference from 50 is that the flow rate is not calculated automatically and must be set by the user.  It is written in Python, and can take an hour or more to slice what Slic3r will process in minutes.

Cura- Developed by an Ultimaker user, this is a front end for Skeinforge 50.  SF50 has some more features such as Skirt, and the calculation of flow rate by filament diameter.  Cura runs it under PyPy, which is a more optimized, faster version of Python.

KISSlicer- developed by a user of Bits from Bytes printers, this slicer is faster even than Slic3r.  I don’t think I’ve seen it ever take more than a minute.

I configured all of these to use the same settings, as closely as possible.  Not all have as many speed variables as Slic3r, so I set all the speeds to 50.  The flow rate modifiers (ie Slic3r’s Extrusion Multiplier) were tuned to output at .42mm thick single wall.  There are some differences in cooling, since Slic3r and Cura could run a fan for small layers, but Skeinforge 39 could not. KISSlicer has fan control, but it runs on all perimeters rather than activating for layers that take less than a minimum time.

The first print I did was Make Magazine’s Torture Test, which they used to review printers. I used Tinkercad to add some extra torture to it.

There are some vertical holes one on side to see how the overhangs are handled at the top, as well as roundness.

1_TinkercadThe arch is a test for overhangs and gradual curves.  The overhanging corner is impossible to do cleanly, but we can see how cleanly they manage.  There are tiny columns and a wedge that tapers to a fine edge.  Also there are interior holes to check for dimensions, and a recessed slot to see how solid top layers midway up the print are handled.

2_TinkercadThere is an array of columns, two of them turned into tubes one of which has a wall thin enough to require a single thread.  Another column has a 45 degree chamfer to the outside and a gradual fillet on the top edge which can create gaps.  The array of columns is a test for retraction, to see if there is stringing as the extruder moves from one column to the other. I also added a bar across the top of the cube to test bridging.

3_TinkercadThe pattern of rectangles on the other side is a test for horizontal detail, which are 90 degree overhangs at various distances.

4_TinkercadA couple of the cube walls are very thin to test the filling of narrow areas.  There is a wide cylinder inside with a chamfered edge.  The underside of that cylinder also has a chamfer, which is a 45 degree overhanging curve to the inside, in contrast to the outside chamfer on that column on the corner.

5_Tinkercad7_TinkercadIn the next post we will get started looking at the results of this print.


5 thoughts on “Slicer Comparison

  1. Hi Ian,

    I have been playing around( extensively ) with Skeinforge and Scli3er using all the settings that have been provided by yourself and others…Thru all my prints I still was not happy about the quality of the prints. I went to and Expo which happen to have the UP Printer there. As soon as I saw this printer in action I realised what my problem, and probably many others, are finding.
    To me the secret to achieve good prints is speed, especially on the perimeters. I adjust my speeds so the Perimeters were running no more than 20~25( sometimes as low as 15 ). This vastly improves the final print.
    I then also have a look at KISSlicer…it is a nice interface, easy to use…and FAST.
    After configuring for the Solidoodle 2 Printer and ran a couple of test pieces…the results were…AMAZING.
    The difference between KISSlicer and the other Slicers is like Night and Day…
    Once you start using KISSlicer you understand how it achieves such quality prints..
    The way it achieves this is in the way it prints the perimeters…for eg if you have a 0.8mm wall thickness, the way it constructs the perimeters is quite clever.
    The outside perimeter is printed the slowest…then the next inside perimeter is slighty quickier and the last inside perimeter is almost twice as fast as the outside perimeter…This all results in very very good prints…
    KISSlicer is way out in front when producing good quality prints…

    Also on another matter, a while ago when printing jobs I was experiencing ridges in the side walls of my prints…external and internal…I spent hours on this trying to work out what the problem was.
    For eg if my print was 10mm high, there would be 6 ridges in the side walls( a log cabin effect )
    This is what the problem is and this could effect anybody with the Solidoodle Printer…
    The Z Axis Leadscrew is purely a piece of threaded rod. If the Z-Axis carriage sticks as it is feed down then because there is so much backlash in the threaded rod, the carriage does not come down uniformly…I took the whole carriage out…regreased the guides cleaned everything and reinstalled…the same problem reoccured…So…how to get rid of this problem…You probably also noticed that the leadscrew rotates of center…Poorly put together…
    The FIX…I intalled an 8mm Ballscrew…Yes that is correct Ballscrew…found a supplier in China and bought 1…cost me about about $60~$70US…it is well worth it…accuracy is great.

    Anyway lots to mull over…I will be interested to see you results…

  2. Regarding slicing times, what CPU are you crunching these through? My system is a rendering rig so my numbers are a bit askew.

  3. I am just finishing up building my printer (im a novice). I am planing on printing some large files build detentions 12x12x48″ is there one that handles larger files better then the rest?

  4. Pingback: 3D Printing – Part 1 | Plaid Spots

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