3D Printing is a complex and versatile activity in which you can customize almost anything about an object, including its weight. However, it might be challenging to figure out how to make a print lighter or heavier without making too many changes to your design or affecting your print’s quality. Don’t worry, though — it’s easy to add a bit of weight to your objects.
There are several ways to do this, namely:
- Make a solid print, not a hollow one.
- Increase the infill density.
- Fill hollow spaces with heavy materials.
- Print with dense materials.
Let’s go through these methods for adding gravity to your 3D printed objects and talk more about when each one might be more appropriate than another. I’ll give you all the details and help ensure that your prints come out just how you want them to.
1. Make a Solid Print, Not a Hollow One
3D Printing a hollow print is less time-consuming, uses less material and is cheaper than creating a solid object.
However, if weight and density are what you’re after, producing solid prints instead of hollow ones is a good option.
If you opt for this route, ensure that your printer’s nozzle extrudes enough filament. Under extrusion happens when the nozzle isn’t releasing enough filament onto the bed or if the filament isn’t hot enough to bond with the rest of the layers. Your solid print may become brittle and break under pressure if this occurs.
You should also ensure that your first layer is thick enough. A thin first layer can lead to gaps in the infill, rendering your print not solid.
Keep in mind that printing a solid 3D model is an extremely lengthy process. Setting your printer too fast to shorten the process can lead to gaps in the print.
There are many factors to consider when committing to a solid print, so make sure you know your stuff beforehand. This video explains the process of Fused Deposition Modeling (FDM), the most common kind of 3D printing.
2. Increase the Infill Density
If you feel that a solid print takes too long, uses too much material, or isn’t as strong as you’d like, you should consider increasing the infill.
Since the infill makes up your model’s internal structure, you will not be able to see it after you pull your object off of the bed. So, making your infill denser, more complicated, and thicker is a covert way to add more weight to a light print.
Adding denser infill means that, although your print won’t be completely solid, it will have a thicker and more complex internal structure, adding to the overall weight.
Different infill patterns influence the strength and flexibility of a build, but they can also affect the weight.
Commonly used infill patterns are:
- Lines: Lines essentially print one direction across the build. It’s the fastest option but doesn’t add much weight.
- Grid: These are just lines printed in a criss-cross formation. It’s a more substantial option than lines while still being minimal effort and lightweight.
- Triangles: Triangles are the most durable infill shape, and they are also one of the heaviest.
- Tri-hexagon: Hexagons are sturdy in shape and avoid bowing due to their shorter connecting lines. Hexagons are a suitable option for adding more weight to your model.
- Cubic or cubic subdivision: Cubic infill consists of a stacked cube pattern that uses minimal material.
- Octet: The stacked pyramid shapes are aesthetically appealing and a sign of strength and additional weight.
- Honeycomb: This is a practical option. It uses minimal material while ensuring adequate strength and flexibility. However, it won’t make your model too much heavier.
- Gyroid: Gyroid infill is the balance between density, print time, and materials used.
- Concentric: This infill mimics the pattern of the build’s external walls and is an excellent solution to the density issue without using too much material.
To make your prints heavier, you’ll want to use the infill patterns that use the most material and set your object for a high infill density.
3. Fill Hollow Spaces With Heavy Materials
You may feel that printing a solid model or even a model with a denser or more complex infill is too time-consuming and expensive. If this is the case, you should consider filling your prints with other materials post-print to increase their weight.
The way to do this is by printing the outer walls of your model and creating a hollow print or one with cavities. Typically, you would fill these cavities during the printing process with more of whatever material you use to print.
However, in this case, you will leave these cavities open to fill them with a material of your choice. Once you have filled them, you place the model back onto the printer bed and cover the holes with a final layer. If that sounds too complicated, you can also glue your print together.
Here are some materials you can use to add density and weight to your 3D prints:
- Sand: Sand is widely available and easily accessible. Filling your print with sand will add weight, but never get the sand wet before putting it inside the model. Damp sand will work as an abrasive and might damage your object, while dry sand will not do any harm.
- Clay: Relatively inexpensive, simple to work with, and sufficiently weighted, clay is an excellent choice to fill gaps in a print.
- Lead or other metals: Inserting metal into your print is exceedingly simple. For the simple method, you can use metal marbles, coins, scrap metal, nails, coiled wire, or anything else you have to fill in the model.
- Plaster: This material is cheap and easy to find. All you have to do is follow the instructions on your plaster container, fill your model, and let it dry.
- Resin: Resin is a bit tricky to work with, and potentially filling your print with it is a messy job. Additionally, it can become quite expensive, depending on the resin you use.
If you choose to experiment with other materials, it would be best to research how each material may react with your printing medium beforehand to avoid damaging equipment or ruining your objects.
To better understand how reactions can make or break a model, read up on the chemical and temperature-related factors that influence a polymer print.
4. Print With Dense Materials
If you want a heavier print, the simplest solution might be to use a denser material rather than fill a lighter one with other stuff later.
Poly Lactic Acid (PLA) is the most commonly used 3D printing filament, but it’s also lightweight. Denser materials that could yield a heftier print are nylon, semi-flexible plastic (FPE), resin, or even metal.
Still, your printer will limit the materials that you can print with. Most printers can only print a handful of filaments due to the limited maximum temperature range for a printer’s parts.
The main things you can do to increase the weight of a print are to:
- Experiment with different infill patterns and percentages. You may even consider printing a solid model.
- Choose a material that you feel is dense or heavy enough to fill cavities in your prints.
- Research how different materials react with each other and get creative!