Originally shared by Richard Horne
A New year #3DPrinting #tutorial for you - we take a look at the benefits of manually adjusting the width of perimeters in Slic3r.
I’m not sure exactly how I feel about this one. Normally, I agree 100% with basically everything Rich says. On this one, I feel like this one isn’t so much a proper method to be using, but rather a stop-gap or hack in order to get around bad slic3r planning.
Especially given how slow Slic3r is compared to others (KISS, Cura, Simplify) - having to slice your object over and over again just to get a “proper” path seems hacky. Though I guess on small mechanical parts like this it probably wouldn’t be too terrible.
Sure, incremental slicing certainly helps, but I’d rather see smarter planning on behalf of the slicer. And all of this also looks to be without “Avoid Crossing Perimeters” turned on?
@ThantiK Do you feel 60% ? 
- Let me answer a few points, this is also for anyone else that is wondering, why bother? -
S) - Yes, it is a little bit of a hack, but the entire point is really for people to be looking at their generated gcode. I see so many people who slice with only automatic settings, then fully print, and then try to work out why they have poor quality from just looking at the printed part. You can spot a few things, but it’s still so important to know what the gcode tool-path-planning (and slicing settings) are actually doing (I think a lot of new users are not learning, some even give up).
L) - The other main point is print time and appropriate settings for a specific model. This is also where people put all sorts of different parts onto one plate and print them with exactly the same settings, that’s not ideal and in many cases can produce poor quality or weaker parts.
I) - I often select similar parts for a print plate and have different settings for each type of plate.
C) - People often fit a smaller nozzle (~0.4mm) in the hope of getting better quality prints, but they use ‘automatic’ settings all the time and then wonder why it takes 11+ hours to print things. With a few tweaks to fatten the printed line widths you can reduce print time by hours and still get perfectly good quality prints even with small nozzles.
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- I’m always unsure about sharing odd tricks and techniques because a lot of people just want to click-and-print. But I still see the reality of good 3D printing as understanding what’s happening and knowing what setting actually change the tool-path. Often just to work out if it’s a bug or bad model causing the ‘issue’.
R) - I have also seen many people abandon Slic3r or Cura because they don’t understand what the settings do, maybe a bit more advice and sharing tricks and tips in the community will help? - got any?
And for this model and many like it, the ‘Avoid Crossing Perimeters’ setting in Slic3r does not actually stop crossing of the gear teeth. With the automatic model ‘0’ the output gcode for a 0.58mm perimeter is almost identical with avoid on or off. (It is also really slow with ‘Avoid’ on, so I just don’t tend to use it)
Back in the old days when Skeinforge was king, you had to set everything manually, so people started to understand what things mattered and how to set or manipulate width over height etc. We all want smarter Slicing - Until ‘Automatic’ is more intelligent it’s still a good idea to be prepared to do some manual setting occasionally.
Did any of that get the agreeing percentage up
For me, after seeing those gaps in the gear teeth, and getting over seeing gaps in the gear teeth 
it raises another good point viz:
How much plastic do we need to put into an object? Are many of us making the mistake of thinking that more plastic (i.e. denser infill) is better?
@Richard_Horne I’m not saying to avoid using this trick at all! It’s an awesome hint and a lot of people would do good to use it. But wasn’t there a branch of slic3r in the past that used “variable line widths” in order to squeeze into tight spaces, and was meant to basically solve the problems that you’re solving now? Did that get scrapped?
The problem with your reference to Skeinforge is with the exception of a very select handful of people, most people didn’t really learn or know any better with what was going on at the time. Most were just confused and often times changed the wrong settings in order to get the effect they were looking for. Like changing their e-steps to get fatter extrudate in order to fill gaps. Or similar silly things.
I think that it’s up to those of us who do understand these problem domains to solve them in a way that the user of the slicing software won’t need all of this extra stuff. About 1/3rd of my support emails are slicing questions right now. I want less of them.
Thank you Rich, this is a fantastic tutorial, really opened my eyes.