Sustainability Tips for 3D Printing

Since I started 3D printing, reducing waste has been a key focus for me. It's beneficial for the environment and cost-effective, making it a win-win situation. In this post, I'll share some practical tips that I've gathered for reducing filament usage in both the printing and design processes. Additionally, I'll highlight areas where I'm seeking further advice and invite the community to share their insights.

Printing Tips 

As much as I want 3D printing to be the sustainable solution to reducing waste in manufacturing, the reality is 3D printing can be very wasteful. There are a number of necessary evils. Skirts, supports, purge lines, wipe towers. Not to mention failed prints, poorly designed prints, or unnecessary prints. 

Here are a few strategies I've been using for reducing the waste during the printing process and a few areas that I'd love some feedback on.

Skirts and Purge Lines: 

While skirts and purge lines can seem wasteful, they often prevent failed prints. For example, with my Ender 3v2, I've often realized halfway through a skirt that I've used the wrong temperature profile, failed to level the bed properly, not properly cleaned my nozzle, etc. 

Although I haven't found a way to avoid them completely, the tip here might be to "measure twice, print once" – double-check your settings before starting a print.

Color Changes and Wipe Towers: 

Those of us with the capability and inclination to do multi color prints may be working with wipe towers to purge the lines and get consistent layer colors after a color change. Frankly I've never dealt with this so I'd love some input from the community for tips on how to minimize waste. 

My current tactic, only having a single extruder, is to initiate the color change (M600 for me) and then just purge until it looks like I'm getting pure correct color. 

This takes anywhere between 50 and 200 mm of extrusion for me and my Bowden tube setup and stock Ender3v2 hot end, so I welcome some feedback for how to reduce this. 

Presumably an upgrade to a direct drive extruder would be one way to reduce, so that's something I'll need to look into. 

Supports: 

Supports are often necessary but can be wasteful and difficult to remove. To minimize the need for supports, thoroughly examine your models and visualize them in the slicer before even downloading the file. Browsing through Printables and Thingiverse, I always try to picture it in the slicer and think of how I'm actually going to pull this print off. 

I can't tell you how many models of Sci-Fi ships my friends have sent me and asked me to print. Mostly I've had to responded with "Too many overhangs!". This went on to the point where one buddy of mine actually bought me a resin printer. Stand by for more trials and tribulations when I get into that, but I digress.  

My first design, the water bottle cap, required supports. Lots of them. To the point where most of the post processing was just digging them out. After that, out of sheer laziness, I started designing to minimize supports.

When supports are unavoidable, I've found tree supports to be significantly better and less wasteful. I used them for the wall shelf model and it turned out great. Since then I've designed for zero supports, so any further tips on supports would be greatly appreciated. 

Fitting parts: 

One thing I've discovered the hard way when printing a part that fits onto or into something, avoid printing the whole part. 

When testing the tolerances for the various containers I've designed I had to come up with a process to reduce the waste. My daughter now has a brand-new unopenable box because I did not follow my own advice. 

Here's my process: 

    1. Import the parts into the slicer

    2. Cut ~5-10mm from the top of each part

    3. Remove the bottom parts

    4. Print

    5. Test tolerance, repeat if necessary. 

While the test parts are still considered waste, it's a lot less waste than having to print the whole thing multiple times. 

Plus if you have a 2 year old and a 4 year old, assuming the fitting parts aren't a choking hazard, the "wasted" parts become inexplicably fun toys!

Failed prints: 

Being the proud owner of a moderately modded Ender3v2, let me tell you a thing or two about failed prints. From experience. Great starter printer, I've learned worlds about the mechanics, the electronics, and the chemistry behind 3D printing out of sheer necessity. 

I see a lot of posts out there about upgrading the Ender so far beyond its original capacity that it's barely recognizable. Frankly I'm fairly proud of what I've been able to get out of the printer with a moderate amount of modding. 

I could do an entire post on what I've done to the thing to get consistent prints, and would be happy to if there's any interest, but I feel the best upgrade I did was the PEI print bed.  

From this experience, I've learned a few things. Level, level, level. Check your settings twice, print once. Calibrate new filament. Ensure your printer is in good working order. Clean your bed and your nozzle. Be cautious before long prints. 

Invest in functional upgrades that focus on getting the job done right the first time, like automatic bed leveling, filament within acceptable tolerance for your machine, and a bed that is best for the job. 

Infill and Walls: 

I prefer to use more walls and less infill for structural stability. I read somewhere (probably Reddit) that walls provide more strength than infill. I've found this to be true in my parts. 

The magic wand I printed for my daughter is just a tall cylinder. I decided to print it vertically because I'm a sucker for aesthetics. 

I upped the walls from the default (4 I believe) to 8. This resulted in the sliced figure to have no infill, just concentric circles as part of the wall. 

This wand is two years old now. It survived the Terrible Twos, Threenager Stage, and her little brother. Granted, using ABS had a lot to do with that, but I think it helps illustrate the point.  

Design Tips

I admit I am not an expert 3D modeler. Far from it, in fact. But I'm my short time I've come up with a few tips to reduce waste. I've been doing 3D design for about two years. I am self-taught and have no formal training at all, so take these tips with a grain of salt and I'd love to hear some tips from the pros. 

Avoid Overhangs: 

Taking a cue from the parts I saw designed by the Voron community I began avoiding overhangs in my designs as much as possible. I chamfer anything facing the build plate at a 60° or 65° angle. This, for me, seemed to be a good balance between aesthetics and functionality.

In the grill knob pictured above I incorporated this inside the knob to prevent overhangs and increase strength, but at the expense of material. 

Factor In Bridging:

One thing I learned quickly when designing a slotted piece, say the tent foot extension, was that you're absolutely not going to get the precise measurements in your print that you painstakingly replicated in your CAD software. If you're designing something to slot on to a 2mm thick piece, you're going to need to account for bridging. 

The bigger the bridge, the more likely you'll have to increase your offset. With the above model, I went with a 0.5mm offset between the lighter blue face of the tent foot and the upper face of the extension highlighted in a darker blue. 

Usually for pieces that fit together I go with about a 0.15mm-0.25mm offset, so this is a significant increase. The good news was, I was able to fit the tent foot into the extension, and the bridging helped keep it secure. Even still, it was a pretty tight fit. 

Minimize: 

One of the things I struggle with is over-built parts. I am neither a mechanical engineer nor a materials scientist. I know, somewhere out there, people way smarter than I have dedicated their careers to determining the minimum amount of material necessary to achieve the desired part strength. 

I have a habit of wildly overestimating. Sure, this makes good sturdy parts, but it is definitely wasteful and something I need to work on and read further into. So, for now, the tip, for me at least, is "you probably don't need it as thick as you think." 

Parametric Design:

This may be more of a time saving tip than a sustainability tip, but one of the things I've done in my designs since I've discovered parametric modeling is setting the offset on faces that are meant to fit to other parts. 

Say my daughter demands a box. A star shaped box. I go through the process of sketching, extruding, splitting bodies, shelling, creating offsets, etc. 

Eventually I've got two parts that have to fit together that have zero distance between the parts. Great if my printer could print with absolute precision but that's simply not going to happen. 

Every printer has different tolerances, so I select one face, usually the lower face that fits on the inside, and offset it. 

Generally, what works for me is -0.15mm of offset. I say generally because the star box required a -0.25mm offset while most everything else seems to require -0.15mm.

Creating a parameter for that offset saved me a ton of time. Again, laziness is my motivator, that's what I'm aiming to do with the site, reduce time and waste. I try to include that tolerance as a parameter with instructions and guidance for every model on this site. 

Overview 

Overall, this is a learning process. 3D printing is a relatively new manufacturing process and in an interesting position of having a wide and diverse community from consumers to industry leaders learning together. In my opinion hobbyists and professionals alike should be concerned with minimizing waste. Let's face it, money is a big factor here. 

Efficiency, waste reduction, and parts that are designed and printed to be stronger with less material used reduces costs, reduces material used, and help us push toward a more sustainable world. Think globally, act locally, they say. It's true, every bit helps. 

I'm certain I've missed a lot. I'd love to hear some more tips for reducing waste in 3D printing. I'd love to hear some comments on my tips as well.