Posts Tagged ‘ slicer

A comparison of Simplify3D and Slic3r Prusa Edition


I printed so many 3dBenchies for this comparison….


I’ve been a 3d printing hobbyist for right around five years now:  I purchased my first printer, a Makerbot Replicator 1 (which I still own, still prints great) in March of 2012.  Since then I’ve used multiple slicers to generate my gcode, but mainly (and in order):  ReplicatorG, MakerWare (now MakerBot Print), and Simplify3D.  And for the time I used them, they’ve all been great.  I’ve also built my own printer a few years ago.

However, and as much as I like Simplify3D:

  • Despite it does so many things so well…
  • The fact that I paid cash money for it.
  • And that their updates are so few and far between…
  • And the updates don’t include fixes to some major issues I feel it has…

I thought I should revisit what slicer software 2017 has available.

I know that slicer software is like religion, politics, and CAD software:  People can get very attached to them.  And there’s a good chance someone out there is going to disagree with my findings : That’s great, I’d like to hear your perspective, leave a comment below.  Everyone uses the software differently, and the things I find important (or not) could be polar opposite of someone else.

Based on a general poll I posted, it looks like these slicers are out in the wild and commonly used.  Yes, there are more, but these seem to be popular:

After reviewing all of them, and for reasons listed below, I decided to investigate Slic3r Prusa Edition.  And mainly that edition over vanilla Slic3r because vanilla Slic3r hasn’t been updated since mid 2015, while the Prusa edition is being actively developed (+ extra fancy features).  I know vanilla Slic3r is still being developed, it’s just been a while since an official release has gone out.

Update:  As it turns out, dev releases of vanilla Slic3r are generated often, so it’s pretty easy to be on the cutting edge, find downloads here.

This is not a post designed to bash Simplify3D and espouse the values of some other slicer:  My goal is to make it an honest comparison of the two software.  It should be noted however, I have over two years of experience with S3D, and only a few weeks on Slic3r, but so many of the concepts of the software overlap, I feel I have a pretty good grasp of it.

Finally, why am I writing this? It’s taken quite a while to do all the research!  Mainly for myself actually:  I wanted to get all my research down on paper to see if I should make a slicer switch or not.  There are so many facets to all of this, I wanted to get it in one place to make sure I wasn’t missing anything.

I will continue to update it over time, see bold “Update” text below.

What I used for testing

  • 3D printer hardware:
    • My custom core-xy C-Bot : It has a 12x12x21″ build volume, auto-leveled on a heated, removable, mic6 aluminum bed covered in a PEI sheet.
    • Runs RepRapFirmware on 32-bit RADDS/Due electronic.
    • All steppers set to 1/128 microstepping using SD6128 drivers.
    • I currently print mainly MakerGeeks PLA out of a .6mm E3D-v6 Volcano nozzle at 230 degrees on a 60 deg bed, with active PLA cooling from a ducted 24cfm fan.
  • 3D Model:  I used the good’ol 3dBenchy as my test model for all comparisons, except the thin-wall compare, it’s linked to below.

So let’s get into it…


Version Tested: 3.1.1

Unique things it does well

These are things I’ve found it to do, that other slicers may not.  Or it does better.

  • Multiple ‘Processes’:
    • A process in S3D is basically a print preset.  And you always need at least one.  The power comes into play however, that you can assign them per mesh to print (if there are multiple being printed), or by layer height.  You can even ‘group’ processes so as to link their similar parameters together, so changing one changes all others (see how this works here).  This is extremely powerful, and arguably one of the best parts of the software.  And when I need it, it’s great.  But honestly 95% of the time I don’t need it.
    • Not that it effects me so much, but it has pre-configured profiles for many printers, allowing a larger market-share to have success with the software sooner.
    • I should note that I’ve found no other slicer that treats “processes” as well as S3D.  This is a major selling point, and brings much power and convenience when needed.
  • Print options:
    • In its ‘Advanced Mode’, there’s a knob to tune just about every aspect of your print.
  • Post processing of gcode:
    • You can modify the output of the gcode via S3D’s own custom syntax.  You can see this post on an example of how to do it.
  • Printer communication & machine control panel
    • S3D has a robust “machine control panel” for operting your printer, issuing gcode, printing gcode either over USB, or via SD.  It also allows you to make your own macro’s that show up in the UI.
  • Manual supports:
    • An area where S3D really shines, is how easy it allows you to place and generate your own support material (vertical columns).
    • Even in ‘manual’ mode, you can place them ‘automatically’, then add/remove them as you need.  A nice feature is you can toggle on/off ‘from built platform only’, so you can generate automatic supports for everything touching the bed, the later add in manual supports as needed elsewhere.
    • Support removal has always been great.
  • Technical support:
    • Yes, they actually get back with you if you email them with a problem.
  • Active forums:
    • Linked above:  A very active community.
  • Gcode previewer:
    • Does a great job displaying gcode through a variety of filters (print speed, feature type, etc).
  • Slicing speed:
    • Fastest slicer I’ve ever used, 3DBenchy sliced in 1 second.
  • Print results:
    • There’s no question that once you get your settings tuned right, S3D produces great results.
  • Object transformation:
    • In addition to translation\rotation\scale of parts on the build platter (either via a manip, of numeric entry), you can also specify dimensions, and it will scale to match.  Handy.
  • Multi OS support:
    • I’ve used it on powerful PC’s, and pretty old Mac’s, and it’s never had a problem.

Things it does not do well

This list is the main reason I started looking for other slicer options.  The “Major Issues” are things that I personally feel really, really need to be addressed.

  • Thin wall detection:
    • Major issue“: If you have a wall that’s .5mm thick, but you’re printing with a .6mm nozzle (or extrusion width), S3D won’t print it.  This drives me (and many others) nuts, considering old slicers like Makerware handled this just fine.  Simply having the ability to ‘opt in’ would be great.  Since I print with large (.6 -> 1.2mm) volcano nozzles, it means many files are simply unprintable.
  • Automatic supports:
    • Major issue“: S3D does a great job with manual supports (that you place by hand, which can be accurate but time consuming), but it’s automatic supports (most commonly used) are some of the worst I’ve seen, because… it doesn’t support any type of stalactite (or icicle) like feature.  While the supports it creates are fantastic, and remove great (better than any other slicer I’ve used), when it fails to create them at all where it should ‘automatically’, that’s a major failure.   I have an ongoing thread here with plenty of pics showing this problem.  This is a straight up bug that other slicers don’t have any problem with.  In fact, Simplify3D, KISSlicer, (Update:) CraftWare and ideaMaker have this problem:  Cura, Makerware, Slic3r, and ReplicatorG all handle this just fine .  Here’s an informative pic with the problem.  Just imagine how this can make your prints fail, I’ve had many wreck because of it:
    • overhangCompare
  • Cost, no trial version:
    • That about says it all.  I’ve been told they’ll refund you if you don’t like it after you buy it.  But seriously, there should be a trial for software like this for new people
  • Timely updates
    • They have maybe one update a year… and since it’s closed source software, you have no idea when its going to be released, or what will be in it.  And the last update was pretty lackluster as far as major bugfixes (anything on this list) or improvements.
  • Listening to their community:
    • While they do have tech support (that does respond), they seem to be completely absent from the forum.  Which I personally find quite questionable, since it gives the impression they don’t care about their user base.   There can be a certain topic that has 5 pages of people voting it up, but you never hear if the developers know, or care.
  • Toolpath simplification of high res mesh:
    • Major issue“: This is another major gripe of mine I’ve talked with tech support about, and they seem to have no want to address:  If you pass in a very high-res mesh from zbrush (for example), that may have a much higher poly density that what can actually be printed, the software will do no sort of simplification on the tool path.  The result is that it still tries to print all the detail, and the fallout is your print having a surface quality of oatmeal.  I have example prints that show this off pretty well, as they transition from low-poly to highres mesh.  Their suggested fix is that you manually decimate all your models.  But this means any time I scale a model, I have to re-decimate it for that particular scale (and how do I know how much to decimate it?).  That’s horrible.  Considering other slicers, like ancient Makerware or Slic3r do this for you.\
    • UpdateThis post of mine talks about the problem more, but here are some pics showing it off.  If you enlarge the pic on the right the quality difference is pretty clear.
    • resCompare_s3d_web foot_web
  • Lumping printer settings, print settings, and filament settings into the same preset/Process.
    • Not the end of the world, but since all these things are saved together, it means I need to have… a lot of processes for every speed, resolution, and filament type combo.  Splitting these settings up (like Slic3r) would only make data management easier.
  • Process Storage:
    • Even though S3D does a great job with it’s ‘processes’, it took a step backwards with it’s v3 release:  Up until then, when you’d save a process, it would save on your hard drive, allowing for multiple people to easily share process values.  But with v3, all process are saved “internally” in the software, making it very hard to do any sort of distributed process sharing between employees.  Yes, you can export them out to your HD, but this creates an extra, unnecessary step.  The issue is discussed here.
    • Update:  In addition, if you ever ‘reset S3D to factory settings’, it will wipe all your custom process and firmware setups without warning.  Which would be a non-issue if theses were stored on disk.  I’ve been bit by this in the past, its painful.

Slic3r Prusa Edition

Version Tested: 1.33.8-prusa3d-win64

Unique things it does well

These are things I’ve found it to do, that other slicers may not.  Or it does better.

  • Splitting printer settings, print settings, and filament settings into different presets.
    • slic3r_printsettings_tabs
    • I love this feature.  I can mix and match printer settings, print settings, and filament settings as needed.  Cuts way down on the number of ‘profiles’ needed vs say, S3D.  Plus they’re all saved on disk, easily shareable.
  • Toolpath simplification of highres mesh:
    • You can specify a ‘minimum detail resolution’ that will help it print higres mesh better.  Great feature.
  • Thin wall detection
    • If two walls are close together, they can be collapsed into one, so as to not cause an overextrusion problem in that area.  In addition, within reason (and discussed below in more detail), it will print a collapsed single wall much thinner than your nozzle width, which is desirable.
  • Variable layer height
    • Powerful new feature allowing you to smoothly adjust the print resolution over height.  See an informative post here.
  • Unique infill:
    • In addition to what you’d expect out of a slicer (hexagona, triangluar, grid, etc) Slic3d has additionl types like cubic and 3d honeycomb.
  • Unique top layer infill:
    • Whoe doesn’t love a hilbert curve for their top layer, eh?
  • Notes
    • Simple, but handy:  There’s a notes page for your prefs, to jot down extra info.
  • Max volumetric speed:
    • A handy way, mainly when dealing with bigger volcano nozzles, to limit how much material you extrude.  Based on resarch, the common thought is a volcano heater can melt about 30 mm3/sec, so you can actually enter that in, to make sure you don’t try to extrude more material than you can actually melt.  Which I’ve done before, it’s not good.
  • Verbose cooling description:
    • A little thing, but they have a human-readable paragraph describing how your print cooling fan is going to work, based on the values you set.
  • gcode postprocessing via scripting language of your choice:
    • This is pretty great:  You can pass in code from any scripting language (Python, Perl, JavaScript, etc) to postprocess your gcode.  I found this valuable when I had to modify the gcode output to support my RepRap Firmwares, by writing a custom pos-tprocesser in Python.
  • Slicing speed:
    • Not as fast as S3D, but still pretty fast.  3dBenchy sliced in 4 seconds.
    • Update:  Based on the v1.34 release, which the release notes state moved to a parallelized slicing system, dropped the benchy to a 2 second slice time.  Nice!
  • Print options:
    • In its ‘Advanced Mode’, there’s a knob to tune just about every aspect of your print.
  • Update: Octoprint connection:
    • It can connect to, and upload gcode directly to Octoprint.
  • Update:  Run it from the command line.
    • Fully scriptable from the commandline, no window needed!  That’s great for custom toolchains.

Things it does not do well

  • Printer communication
    • Vanilla Slic3r  doesn’t have this option at all (yet, I hear it’s in the works).  It just means you need some other sender software like Printrun or Repetier Host (or, ironically, Simplify3D).
    • The Prusa edition has the option to connect directly to your printer over a serial/usb connection, but I’ve been unable to get it to work.
    • The current dev (non-release) version of vanilla Slic3r does have this option however, and I’d tested it successfully.
  • Thin wall detection:
    • This is a pro above, but I also found it to be a con:  There were issues on my 3dBenchy tests (mainly the flag-pole hole on the stern) where it would collapse thin walls, but not replace them, causing gaps to form in the walls.  Disabling this option caused noticeable over-extrusion in some areas.
    • Update:  You can track this issue here.
  • Mac support:  It crashes a lot on my (old) mac.  No problem on my PC.
  • Update : Adjusting settings per layer height:
    • Simplify3D’s process are great for this, and while Slic3r does allow you to modify ‘print settings’ per model, I’ve not found a way to vary it by layer height.  Sometimes I want to vary the filament temp over a z-height to see the effects:  Easy in S3D, I’ve yet to find a way to do it in Slic3r at all.  Finally, Slic3r only lets you modify the ‘print settings’ per model, you can’t adjust printer or filament settings, which would help greatly.
  • Update : x3g support:
    • This only matters if you have a Makerbot printer (like myself), but while you can export a Makerbot-flavored gcode, you’ll still need some external tool (like gpx) to convert the gcode to x3G.  Technically since Slic3r supports postprocessing of gcode, it could call out to a x3g converter via a scripting language of your choice as well.
  • Update:  Saving/loading ‘scenes’:
    • It seems a bit awkward to save and load a ‘scene’.  To me, a ‘scene’ is  the current 3d mesh on the platter, plus all the current machine, print, and, printer configuration states.  You can do it, but (instead of the File menu) via “Platter -> Export Plate as AMF…” (Additive Manufacturing File Format).  you can later “Add” the xml file that process generates, which has the effect I’m after, it’s just a weird/clunky process.
    • Update:  I’ve read that per v1.34.1 it now supports a .prusa format that should handle this… but I can’t actually find that functionality in the software.

Comparing Simplify3D & Slic3r’s successes & failures

  • Print Quality
    • They both print great, in my opinion, see the below section with all the pretty pictures.  After setting up similar profiles in both slicers and printing 3dBenchies, the results look different, but great.
  • Overall level of print settings:
    • They both provide a similar level of knobs to twist for designing your print settings.  A wash.
  • Setting organization:
    • While Simplify 3D’s ‘processes’ are great, based on the fact that I use multiple ones so infrequently, I give Slic3r the win here, since it allows you to split you printer settings, print settings, and filament settings to separate presets, while Simply3D lumps them all into one.  Plus Slic3r’s are saved on disk, while S3D hides them inside the software.
  • Gcode previewer:
    • S3d’s better than slic3r for the fact it has more ways to preview the gcode.  However, both of them physically render the gcode about the same.
  • Gcode postprocessing:
    • Slic3r wins here, with it’s ability to use any scripting language.
  • Printer Communication:
    • S3D does a great job with its Machine Control panel.  Update:  Slic3r’s only seems to currently work in a dev branch.
  • Supports:
    • The supports that S3D actually creates (manual or automatic) are fantastic, but when it completely fails to ‘automatically’ support certain features that cause print failure, it’s just sad.  Slic3r’s supports are pretty standard, but don’t fail when they shouldn’t, so it gets a win for just being status-quo.  Both software could learn from the other.
  • Object Transformations:
    • S3D wins here, providing more tools that are easier to use.
  • Tech support & forums : S3D for the win, just a bigger community (or better communication platform) it seems.  It’s not that Slic3r doesn’t have that, S3D’s just seems more active.
  • Thin wall detection : Even though Slic3r has some problems, the fact that it recognizes them at all (compared to S3d) is a win.
  • Cost : You can’t beat free, Slic3r FTW.
  • Software Updates:  The Prusa Edition of Slic3r seems very actively developed… who knows when S3D will get another update, or what it will even have.
  • Highres mesh toolpath simplification:  Slic3r clearly wins here, realizing this is an important aspect of any highres model.
  • Setting storage:  Slic3r for the win here:  All if it’s printer, print, and filament settings are stored on desk in ini files, easily accessed by others, while S3D hides all the settings in the software itself.
  • Update: x3g support:  S3D wins, supporting it natively, with no extra steps needed for export.
  • Update : Slicing speed:  S3D wins, but with the latest Slic3r release I tested, the gap got a lot smaller.
  • Update : Scene saving/loading : S3D wins, it behaves like you’d expect any software too.  While you can do it in Slic3r, it’s just a bit clunkier.
  • Update : Overall experience:  S3D feels like a more polished piece of software, while Slic3r sill gives me that ‘shareware’ vibe from the 90’s.
  • Update: Setting customization per model / height:  S3D clearly wins here with it’s processes, assignable per model, and per z-height.  Slic3r has some nice options, but they’re not nearly as robust.
  • Update:  Command line api access:  Slic3r has it, S3D does not.

Things I didn’t test

  • Supports : Since I did this entire test with the 3dBenchy, which requires no supports, I didn’t feel it was important to test them.  But I’ve used plenty of supports generated by S3D in the past, and they were always easily better than the older slicers I used like Makerware or ReplicatorG.  I’ve actually not ever printed supports in Slic3r, just looked at the gcode output.
  • Other slicers :  I was considering mixing ideaMaker, Craftware and Cura into this test… but I’d probably never have finished it.

3dPrint Comparison

I should be noted that all prints have had zero cleanup work done to them.  This is to show all possible flaws.

Print Stats

I did most of my testing with the 3dBenchy model, trying to make sure both slicers had similar values.  This is what I printed with:

  • 280 micron z layer heights (‘medium res’ for a nozzle this size, set to full z-stepper steps).
  • .6mm E3d-v6 volcano nozzle, extruding at .72mm.
  • 2 shells, 3 top and bottom layers.
  • Triangualr infill @ 30%.
  • MakerGeeks Urban Camo PLA extruded at 230 deg, with a .97 extrusion multiplier.
  • Printed at 60mm/sec with active filament cooling, and slowing layers down for details like the smoke stacks.
  • The gcode for both slicers were sent over USB, via S3D.

Printer issues:

  • It should be noted my bot has a slight z-wobble I’ve been working on addressing.
  • Even though I think I have it tuned in for that filament, I feel like my tests were slightly over-extruding.

Print time and weight:

  • Both slicers generated prints weighting 15g.
  • Both prints took exactly 41 minutes.

Visual Gcode Comparison

On the left is Simplify3D, on the right is Slic3r

s3d_bency_gcode slic3r_bency_gcode

You can note the nice on-screen legend that S3D provides, not to mention it has many other display modes.  With Slic3r, on the right is what you get.  Visually, they’re about the same aside from the colors used.

Poll Results

I know I’m biased about what I think are good/bad print results.  I though it would be interesting to see what others thought, that really have no experience with 3d printing.  I did a poll at work where I brought in benchies sliced in both software(shown in the pics below), put it in the kitchen, and over the course of the day let people vote on which they thought was ‘better’.

I had a total of 57 people vote, and by 2:1, they chose the Slic3r version over S3D.  I didn’t tell them anything about how they were made other than “I’m comparing two different prints, what do you think is better?”.  I should also note that a number of people abstained saying “I don’t see any difference”.

Do I feel Slic3r’s visual results outweigh S3D’s by 2:1?  Not at all.  But I still find the results interesting.  Take them for what you will.

Visual Print quality comparison

Click on images to expand.

Side By Side

Beauty shot, side by side, S3D on the left, Slic3r on the right:


Pretty darn close!  Slic3r has slightly more stringing, but at a glance they look like twins.

Individual Simplify3D & Slic3r closeups:

s3d_closeup_web slic3r_closeup_web

Thin wall comparison

Since the bencny wasn’t the best test for this, I down laded a “thin wall test” from Thingiverse, and ran them through both slicers.  I didn’t print these, but I didn’t need to:  The gcode preview tells enough.

FYI, the walls on the top start at .05mm (on the left), and end at 1.0mm (on the right).  The walls on the bottom start at 1.0mm (on the left) and end at 3.0mm (on the right).

Again, I generated this gcode with a .6mm nozzle, but with an extrusion width of .72mm (20% over).


Did not do well at all.  It didn’t start printing until the wall with was greater than my extrusion width, so it left out all walls under .75mm.  Kind of hard to print anything architectural related at scale with this limitation.



Did great:  It was able to detect and deal with walls almost 1/3 the width of my nozzle, the first one being .25 mm wide.  Note, this was with “Detect thin walls” turned on in the settings.  With it turned off, it had the exact same results as S3D.


Slic3r ‘Detect thin walls’ issues

Interesting findings:  As mentioned above, Slic3r allows for thing wall detection and collapse, S3D does not.  The above benchy pics of Slic3r have the “Detect thing walls” feature turned on.  But I figured out, it was collapsing more than it should, in the case of the flagpole : There’s a small hole in it, which is also shown in the gcode itself:

slic3r_thinwall2_web slic3r_flagpole_hole

Turning this feature off fixed the flagpole, but caused a slight over-extrusion in other places, like where the bow meets the sidewalls, visualized in this comparison:


Note on the right benchy, the line running parallel to the bow, below it.  But also go look at the top/first pic of the S3D/Slic3r compare above:  You can see the same artifact in the S3D print as well.

The thin wall collapse does help give better definition to features though, compare the portholes in these to Slic3r prints:


Note how the porthole on the left has better definition.  It looks better than S3D’s as well.

In Conclusion

They’re both great pieces of software, and they both a have many features in my ‘pro’ sections.  But based on the cost involved, how Slic3r has matured, and how few cons Slic3r has in comparisons to S3D’s cons, I’d have a hard time recommending S3D off the bat to someone new to this:  Give the free software a shot.

For myself, I’m definitively going to give Slic3r Prusa Edition a look:  Considering how it addresses all my ‘major con’ issues with S3D (correct automatic supports, properly handles highres mesh, deals with thin edges), I’m going to invest some serious time in it.  I think sometime in the next few months S3D should have another release if they follow years past, I definitively look forward to that will bring.

Finally, I’d like to give some suggestions to the S3D dev’s if they ever end up reading this:

  • Regularly comment on the forums.
  • Expose upcoming features & bug-fixes that are in development:  If I knew all the problems I discussed above would be fixed in an upcoming release, I’d be far less likely to spend the hours I have looking at other slicers.
  • Release more than once a year.
  • Basically, stop being such a black box.
  • Charge a reoccurring fee rather than a single upfront lump-sum:  I’d happily pay, say 5$ a month for an ongoing subscription where the above issues were met.  The OctoPrint Patreon subscription model (that I contribute to on a montly basis) is a great example of this.


Note:  I’ve updated this post to reflect the most recent 3.0 release, in June 2015

I started 3d printing in March of  2012 on my Makerbot Replicator (1).  I used ReplicatorG as my slicer, since that was the primary option at the time.  When Makerware (now Makerbot Desktop) was released I switched to it, and never looked back.  I’ve found success with it, and really only have a few complaints.  Namely that it slices very slowly (can take hours in some cases), and while you can make custom profiles (which I use), it’s clunky editing a text file (I shouldn’t really complain about that, considering how much programming work I do).  I eventually got Sailfish firmware loaded on my Replicator 1 as well.

Christmas 2014 I decided to gift myself with Simplify3D (S3D below): I’d read a lot of good about it online, and decided to give it a shot.  $140 isn’t cheap for a dedicated slicer with no trial version, but bit the bullet anyway (well, after testing it for a few weeks at work first).

In July of 2015 I finished building a new Core-XY bot running Marlin, and now use S3D for its slicing as well.

This blog post will be a continuing repository of my thoughts as I continue to learn and work with it:  S3D does a lot of good, and up until the release of 3.0 there were several areas that rubbed me the wrong way.  Note I started working with version 2.2.0, which sounded like a pretty major update, and have been pleased with many bug fixes in 3.0.  Also know that the bulk of the “Cons” (many of which have been fixed in 3.0) discussed below have already presented directly to the S3D developers.

This will be organized into three main sections:

  • Pros : Things I really like about it.
  • Cons/Bugs : Things that could be done better.
  • Workarounds : Cons that I’ve found solutions for.
  • Fixes : These are past cons/bugs that later updates have addressed.
  • Conclusions : Overall thoughts

My setups:

  • Home:
    • Makerbot Replicator 1 with Sailfish Firmware.
    • Custom-built Core-XY rig running Repetier firmware & RADDS electronics.
    • Simplify3D 3.0.0 on OS X 10.10.1
  • Work:
    • Makerbot Replicator 2X with Sailfish Firmware.
    • Simplify 3D 3.0.0, Windows 7


There are more things than this I consider “pros”, these are just some of the stand out ones I’ve encountered.

  • Really Fast Slicer : I’ve played with Cura and I’ know how fast it is. I’ve not compared S3D’s speeds to it.  But compared to Makerware, it’s exponentially faster.  Minutes in Makerware are seconds in S3D.
  • Good quality output : At minimum, prints just as good as the best stuff I got out of Makerware.
  • Great GCode Previewer : Being able to preview every layer of the slice, and to visualize the speed in which it will be printed is invaluable.  That coupled with the slicing speed turns this into an actual iterative process:  Change a few settings, preview.  Change a few settings, preview. Etc.
  • Cross Section View : Allows you to visualize any cross section of your model, or GCode.  So handy!
  • Many Knobs To Twist :  Each “Process” is organized into multiple tabs giving you complete control over just about every setting imaginable.
  • Tooltips : A little thing, but every setting in a Process has a tool tip telling you about it.  Which is really important, considering there’s no official documentation.
  • Adjust Settings Per Layer : Great option:  You can set each “Process” to a layer range, completely adjusting all the settings as needed.
  • Different Settings Per Model : Not only can you split settings based on layer, each individual model can get its own Process with individual settings.
  • User Support : Getting feedback/support/help from the developers seems prompt.
  • Forums : Active forums.
  • Supports many printers:  You can take your knowledge with you as you change hardware:  When I built my new machine, even though it has completely different firmware than my previous printers, I was able to roll all my exiting S3D knowledge right into it.
  • Tethered Printing : If printing tethered, can adjusting settings (speed, extrusion, temp) on the fly while printing, issue live GCode commands + get a live play-by-play in the GCode previewer.
  • Great Support Material Creation : Create it automatically or by hand, either way it prints well and removes easily.
  • Successfully prints intersecting models : This is a big one:  I’ve had issue in the past (Makerware) where two models were brought into the build platform and made to intersect (on purpose) : Makerware didn’t always like this. As a test I brought in 1500 separate obj files, all intersection in different ways, and it sliced perfectly, combining mesh were appropriate so there was no intersecting extrusions.
  • Fantastic Support Generation:
    • Not only does it create create great auto-generated support (except a bug mentioned below), it allows you to place your own.  In addition, it allows the support to become more complex as it approaches the surface, to speed support printing and provided better support overall.  Plus, it tears free amazingly well:  In the below pic, S3d is on the left, Makerware is on the right (painted white), they both took around 25 hours to print (they’re the size of big grapefruits):  The makerware supports required pliers to remove, and there is still much cleanup needed.  The sS3d support easily removed just using my fingers, and left minimal scarring on the print.
    • support_compare(click to zoom)
  • Great infill options (new in 3.0)  : A variety of different infill for both strength and speed.


  • No (official) Online Documentation : While there are tooltips for all the settings, there should be a more detailed overview of all the setting online.  Their support is really responsive, but I can’t see a downside to providing real documentation.
  • The “Center And Arrange” option only moves things, won’t rotate them : The tool could use a better packing algorithm that not only moves stuff around, but can intelligently rotate them as well.
  • The Estimated Print Time can be wildly off :
    • Makerware is pretty consistent when estimating time:  It always over-estimates by about 20% in my experience.  S3D however is all over the place:  I’ve had a print estimated at 3.5 hours take close to 7.  Most of the time though, it appears to underestimate the print times, but it can vary from 50%-10%.  Can’t make much rhyme or reason out of it, other than it’s a pretty useless number :(
    • After working with the software, it looks like print times on Makerbot machines (Sailfish firmware) are way off, but on machines with Marlin firmware, it’s pretty accurate.  I’m wondering if it has to do with the Makerbot x3g conversion?
  • No Trial Version : Since this is paid software, make a trial version so more people can try before they buy.  Maybe it disables save, but even giving access to the GCode previewer & process settings could sway more people its direction.
  • Auto-generated support can completely miss ‘floating features’  : Picture a stalactite hanging from a cave ceiling:  S3D won’t auto-place support under it’s tip:  It’ll let it hang free in space, completely unsupported, failing the print.  It’s up to you to check over you model completely, making sure support has been placed correctly.  I have a thread on the forum here illustrating this.  I really hoped this would be fixed in 3.0, but it has not :(
  • It does no toolpath simplification for highres mesh:  This means high-res small stuff will print poorly, since you get super-small toolpaths that make your machine do a dance.  S3D argues you should give it good mesh.  I argue that I shouldn’t have to auto-decimate every mesh I throw at it (since auto-decimation can screw up fine features)… makes printing scaled stuff far more of a hassle that it should be.  I show this issue visibly via this post, under the “High Res – Low Quality” section.
  • Thin wall printing isn’t supported.  Say you have a 1.0mm volcano nozzle, and the wall you’re trying to print is .5mm thick : The slicer will just disregard it.  This is a hot topic in the forums.  If a slicer like Makerware supports it (they call them spurs, or single-thickness walls) S3D should.  Otherwise you have to generate new models for new nozzles, what a nighmare.
  • Black box:  They tend to release a new version once a year, but you don’t know when, nor what features will be in it.   I’ve asked them if there was any sort of known list of improvements, and none was provided.


  • Holes In The Roof :
    • I had a continual problem when printing at 100 micron where there would be holes towards the top of the roofs in my prints.  Driving me crazy.
    • I finally tracked down the problem: I would create my 100 micron profile by duplicating a 200 micron profile.  In the 200 micron file, I’d have 3 roof layers set:  That’s a roof .6mm thick.  But I wouldn’t adjust it in the new profile (since I’m used Makerware, which allows you to define a fixed roof thickness, rather than number of roof layers).  So when it would print its roof, it would print 3 layers at .1mm:  A total of .3mm thick.  The equivalent of one and a half .2mm layers.  Not nearly enough for coverage.
    • The lesson learned is:  When you change your layer height, you also need to change your roof layers (and floor) to match.  I’d print 6-8 roof layers at 100 micron to get adequate coverage.


  • Weak Infill : Addressed in v3.0
  • Only One Type Of Infill : Addressed in 3.0
  • Not Ready For Dual Extrusion Yet : While I haven’t tested this yet, it looks like 3.0 addresses many dual-extrusion issues.
  • No Undo : Addressed in 3.0
  • When translating mesh, it always snaps to a top view : Addressed in 3.0
  • Unable to fully translate\rotate\scale on all axes interactively with the mouse : Addressed in 3.0
  • No Option to “Scale to Max Print Size” : Addressed in 3.0
  • When in GCode preview mode, you can still accidentally move mesh : Addressed in 3.0
  • No Orthographic Cameras : Fixed in 3.0.  But it’s sort of hidden in the preferences window, so it’s easy to toggle.
  • Model Settings Window” related :  All fixed in 3.0
    • When changing values via the spinners, it’s a fixed (large) step amount.  These should be user configurable for precise control.
    • Can’t change “Object Size Dimensions” : You can change the scale of an object, but you can’t set it’s absolute size.  C’mon, Makerware does it…
    • Changing the Trans\Rot\Scale values don’t effect anything in the “Calculated Properties” section until you reopen the window: It should be a bi-directional connection allowing either to be edited.
    • It’s a modal dialog, meaning you can’t do any interaction with the rest of the software while working with it.  Like say, change the camera view, since this dialog is blocking the view of your model…
    • I takes up a lot of screen real-estate:  On my laptop it obscures a quarter of the screen, making it a dance to move it to some location where it won’t obscure the model I’m trying to transform (see the above issue).
    • The transform values aren’t saved between sessions.  Meaning, if you translate, rotate and scale an object to specific values, after you save, close, and reopen the scene, the model will be in your transformed position, but those settings will be set back to zero:  Makes it hard to later make precise adjustments based on the original size of the model
  • Strange behavior when changing the default hotkeys : I’ve not tested this, since the new hotkeys are pretty good, but I’m guessing this is fixed in 3.0


  • Is S3D worth the money?
    • This is really a personal questions, based on your needs.  For myself, especially since the release of 3.0, I’d give it an easy yes.
    • If you were going to make a business out of 3d printing, I’d give it a resounding yes:  While I’m no expert in all the slicers out there, I’m not aware of any other slicer that provides you with the features S3D has.
  • With v2.2, it felt close to greatness, but fell a bit short.  With the release of 3.0 though, addressing so many issues, it really feels like a full-featured piece of software now.