What You Need to Know for 3D Printing Large Objects
3D printers come in all sorts of shapes and sizes from desktop printers to huge industrial printers. If you’re using a desktop 3D printer, chances are you might want to print something that is larger than the build volume of your 3D printer. When this happens, you’ll have to split up your model into multiple parts for printing and assemble it after printing. In this guide, we’ll cover some the techniques for splitting parts, and go over some of the methods for combining each of your pieces together.
How to Split Parts for 3D Printing Large Objects
One of the primary reasons people decide to split their models is to make things larger than their printer’s build platform. By cutting up parts into bite sized pieces, you’re able to print things many times larger than your machine would normally allow.
People also split parts to make them easier to print. The Eiffel Tower for example, has a number of different overhangs and requires support structures if printed all in one piece. By splitting up the tower, parts can be printed individually and oriented in such a way as to have fewer overhangs and require no supports. The pieces are attached together at the end to make the full tower which ends up being faster than printing it all in one piece!
Splitting 3D Objects with Meshmixer
We’re going to be using a free and Open-Source program called meshmixer to split up our parts. You can download it here. This is great for basic cuts but more advanced users might use something like Blender to make complex adjustments.
We’re going to be using the plane cut feature. Import your model into meshmixer and select “edit” from the side menu. Next select Plane Cut and choose the “Slice (keep both)” option from the dropdown. Now you can draw a line with your cursor selecting where you’d like the model to be cut. Select “Accept” and although it may not look like much, your model is now made of two parts.
To save the parts individually, we’ll be using the Object Browser. Press “Shift-Y” on your keyboard to bring up the object browser. Select the half you’d like to export and then go to “File -> Export” and use your file format of choice.
Attaching your parts together
There are a few different adhesives used for attaching parts together. One of the most popular is super glue. Make sure that the main ingredient in cyanoacrylate as this works especially well for 3D printed parts. Many FDM materials like PLA and ABS work well with super glue as do most SLA resins.
Certain materials don’t bond well with super glues. The most common include flexible materials and nylons. The adhesives for these are usually more specialized – Taulman makes a nylon specific glue for example. A high strength epoxy may perform better in cases where super glue isn’t effective.
Even after gluing, you might notice that there’s a small seam between your parts. A good tool for removing these seams is a plastic filler material called bondo. This is especially useful if you’re going to paint your part afterwards. Bondo is applied in thin layers and then sanded to match the contours of your model. This creates a smooth uniform surface that fills in gaps and prepares your part for painting!
The R2D2 pictured above, is made up of of over 100 parts all attached together!
Check out some of our favourite models that make use of printing in multiple pieces to create things much larger than your typical 3D printer can:
Sci-Fi Gun Prop by Doodle_Monkey
Wearable EP7 Stormtrooper Helmet by ducampv
For a closer look at how to create 3D printed objects larger than your build platform, check out this detailed tutorial.