Why Do People Always 3D Print That Little Boat? Benchmarking Your 3D Printer.
For anybody who has spent time researching 3D printing, there's a good chance they have come across many examples of this tiny boat model. If you're new to 3D printing you might see this and not think it's significant, but there's a reason that you see this tiny ship so often. (If you'd like the model, check it out on Thingiverse here: https://www.thingiverse.com/thing:763622).
This little boat is called Benchy, and printing this model is a great way to test settings and the quality of your 3D printer. It is printed so often because the various features of the model make it a great benchmarking tool, hence the name, Benchy. There are several factors about your printer and settings that printing this model will tell you. The goal of this article is to shed some light on why you may want this model readily available for 3D printing. If nothing else, it might at least give you some good reasons to print Benchy for yourself!
Why Benchmark?
Regular benchmarking is an important part of maintaining the quality of your prints. Before going in to specifics about Benchy, I'd like to cover general reasons why it's nice to have a benchmark model saved to easily be printed when needed.
First, to cover the general concept of a benchmark. A benchmark is a baseline for quality. It is something that can easily be compared to other examples of that thing so you can verify the level of quality or success vs a standard. Companies might use a benchmark number value to measure sales growth within their industry; or a factory might create a few 'perfect' benchmark examples of a piece of hardware to keep on hand and regularly check against newly manufactured pieces to ensure the quality stays consistent over time.
For example, a company that manufactures nut & bolt hardware might keep a few "perfect" examples on hand. They would occasionally check newly manufactured items against these perfect examples to ensure standard quality over time.
Benchmarks are important for maintaining consistency and if the quality of your 3D prints is important to you, then it's a good idea to set a benchmark for yourself.
Benchmarks in 3D Printing
Now to apply benchmarks to 3D prints in the home. Personally, I view these benchmarks in two different groups.
Benchmark Group 1: Self Benchmarks
I'm the type of person who competes with themselves. I like to try and improve at a steady pace, so a self benchmark is an important thing for me to have. Basically what I mean by "self" benchmark is that I print a model with my current settings, and then see where there might be areas to improve. The next time I print something, I will make a subtle change to the temperature, print speed, or retraction speed; and I can compare it to the first model I made. (We'll discuss these specific comparisons in the "Why Benchy?" section of this article.)
If the new model is better, I keep those settings. If the new model is lower quality, then I go back to my old settings or try to change something else. By using this iterative process with myself, I can steadily improve my 3D print quality and enhance how my 3D prints look over time.
Benchmark Group 2: External Benchmarks
External benchmarking is one of the reasons Benchy is so great. To me, an external benchmark is only useful if there are lots of good quality examples. As I write this article, the Benchy page on Thingiverse has over 3,000 "makes", with photos to compare your own Benchy to. This makes that page a super valuable resource. Once you print your own first Benchy, you can go to that page and flip through all of the different images and compare your quality to the quality of others.
Not only is the Thingiverse page a great resource, but posting your own picture of a Benchy on nearly any 3D printing forum with your printer settings and asking for feedback can also yield great results. Even if there isn't a current forum thread running about Benchy, there is nearly a guarantee that several people in that forum have printed their own Benchy (or multiples) and can give you some great, direct feedback on how to fix issues if you have them.
This outside help and comparison is a good resource to improve the quality of your prints, and to get specific feedback on how to do so.
Reasons to Benchmark Your 3D Printer
After many successful prints You might be thinking, "My settings are perfect! Why mess with what isn't broken?" Well, to an extent you may be right. If you've spent any significant time with your printer and regularly get high-quality prints, you're probably in good shape, for now. Consistency of print can change over time, even with the same settings. So here are a few scenarios that might be a good time to benchmark.
Filament Changes: This is the most common reason I like to have some kind of a benchmark model on hand and ready to go. Generally, the same type of filament from a brand will maintain good print quality with the same settings no matter which color you choose. A purple Hatchbox PLA filament will probably print nicely with the same settings you used for a a yellow Hatchbox PLA filament. It's still nice to have a standard 'test' model around though to check for yourself with each new color. The bigger difference comes when you swap between brands of filament or material types. I often use Hatchbox, 3D Solutech, ProtoPasta, and AIO Robotics (among other brands) filaments depending on the price and the colors I need. I find that differences in brands often require different settings. Also, if you are changing materials; for example from a PLA to ABS, or PLA to a Wood-fill PLA; those most likely will require different settings. So having a test model on-hand like Benchy that doesn't take long to print and that you are familiar with makes filament changes easy.
Temperature Changes: You may or may not experience this issue where you live, but the area where I keep my printer in the home is susceptible to temperature fluctuations. Because of these changes, I often have slightly different temperature settings in the summer than I do in the winter. There can sometimes be a difference of 10 degrees C in my "ideal" printing temperature based on how the air temperature around the printer changes. Having a Benchy available for me to print lets me get a good start at the beginning of a new season.
Moving: Several years ago I moved entirely across the country. This required disassembling my 3D printer, packing it on a moving truck, and then re-assembling it when I arrived at my new home. That is an extreme case, but it doesn't require a cross-country move to cause potential issues with print quality. Even shuffling your printer setup from one room to another within your home can cause print quality issues. Again, here comes Benchy to the rescue! If your first print in the new location is a Benchy, you can test it against another Benchy benchmark you made prior to the move to see where the quality might have changed, and where adjustments have to be made to either settings or physically to the printer itself.
Why Benchy?
Now, to get to why Benchy is such a cool little model. I'm going to cover a few specific areas that you can look at after it's printed that you can use to determine the quality of your print.
Overhang Tests:
The wheelhouse in particular has some overhang sections that can show you a couple things. If you see that these areas look rough or droopy, there's a good chance it means your printing temperature is a little high, or that your cooling fan could be improved. The front of the wheelhouse in particular is great to check this out, since it's a long, straight section where the printer has to print in mid-air to complete the top of the window.
Basically, a droopy overhang means the plastic isn't getting enough time to cool and set before gravity takes hold of it. But a more effective fan or that cooler temperature to start with can help alleviate your overhang problems. In my example print, the top of the front window is a little droopy, as well as the top of the arch on the side door. This means I should probably look in to finding a way to improve my cooling or adjust temperatures for better results in these areas.
Infill Testing:
The fat, tugboat-style base of the Benchy requires infill to make sure the top deck of the ship and the wheelhouse can be printed. As your printer is going, take a look at it before the deck of the boat starts printing to get an idea of the quality.
Is the infill looking consistent and solid? Are there gaps or does it make a nice looking grid? Those are the types of things you want to determine at this stage in the process. In my example print pictured below, the infill looks reasonably good. It's solid, plastic is evenly distributed, and it will provide an excellent base for the top deck.
There is a little bit of "stringing" in between the squares that looks a little messy. I could probably adjust retraction settings a little to reduce the amount of excess filament, but that's aesthetic. Overall, the quality of the structure is high and i'm happy with the result.
Small Detail Testing
The 3D Benchy boat has a few small details on various parts of the model that you can look to to make sure that small things can print well.
There are several detail features to look at. The ridges of the ship's wheel, the small hole at the rear of the boat, the edges around the window, and the smokestack at the top are a few. These small details will seem a little 'mushy' if the printer isn't getting enough cooling, or if the print temperature is too high.
Alternately, if your printer is changing direction too fast to accommodate these small details, you will see some wavy lines throughout the model. For example, I can see in the below print around the edges of the windows & doors has an odd but consistent pattern laid in to the plastic. I might want to consider printing more slowly, or even double-checking all of the screws on the frame of my printer to make sure it's rigid and not vibrating as the print nozzle changes direction
Bottom and Top Layer Testing:
These are some of the things that can be most frustrating to me even as a fairly experienced 3D print hobbyist.
First, and most frustratingly, we will talk about the bottom layer. I say frustrating because it can take some serious effort to overcome a bottom layer that doesn't stick well. For the most part, the Benchy model has a nice flat base so you can make sure that the plastic on the first layer looks even. Secondly there are letters inset into the Benchy just slightly. These letters add an extra level of detail and while they might be annoying when your printer isn't running well, if you are able to get a good quality first layer including these letters then you know you're on the right track to an excellent overall print.
Finally we will talk about top layer testing. The Benchy has a few opportunities for you to check out the quality of your top layer. The first opportunity comes with the small well in the top of the boat that is just behind the wheelhouse. This small section helps you determine if your infill setting is good because it prints without being attached to any of the edges of the boat. If you had zero infill it would just be floating there. The next top layer the Benchy comes to is the deck of the boat. As this prints you can check out the quality of a larger area of top layer. If you have some problems with it and the layer has holes or is bumpy then you know there is an adjustment to make either in the number of top layers or better infill for the top deck too lay across.
Summary
Hopefully this article gave you some solid insight as to why you might want to not only print a Benchy, but also have one saved to your computer as a standard model to print any time a change is made. A change in filament, room temperature, or mechanical changes to the printer (among other things) can all affect the quality of prints. Having a benchmark like Benchy available means that you can make steady improvements to your prints over time, and that you can easily detect any changes in print quality when a change is made to the printer. The popularity of Benchy also means that you can go online and see plenty of other examples of the Benchy to compare yours to, giving an excellent external benchmark to determine your level of quality vs. other 3D printers.