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Read articleLearn how to design and 3D print interlocking joints (e.g. finger-, dovetail- and puzzle joints) to assemble your 3D printed parts.
Interlocking joints are a common method for connecting components that are regularly assembled and disassembled. The use of interlocking joints allows:
This article will discuss the common applications of interlocking connections used in 3D printing, and recommend the 3D printing processes most suited to interlocking joint production.
The table below provides a quick overview of the most common 3D printing technologies and whether they are appropriate for printing interlocking joints:
Process | Description |
---|---|
FDM | Low cost and effective way of manufacturing interlocking joints but lower accuracy than other printing methods. ABS better suited than PLA due to its improved ductility |
SLA | High accuracy but can be very brittle unless using a “tough resin” |
SLS | Good for interlocking parts as parts have high print accuracy and good strength |
Material Jetting | Good strength and elasticity combined with high resolution details makes material jetting ideal for interlocking applications |
Binder Jetting | Not suited for interlocking connections |
There are 3 forces to consider when designing interlocking joints:
Friction - the critical force that holds the joint together. The tighter the joint is, the higher the friction and the more difficult it will be to pull apart
Tension - the force that acts to pull the joint apart
Shear - the force perpendicular to tension that pulls the joint sideways (a tearing force)
When interlocking joints are manufactured in injection molding, a tolerance of 0.1mm is applied. For 3D printing, tolerances vary between technologies as summarized in the table below.
Process | Interlocking parts tolerances |
---|---|
FDM | 0.5 mm |
SLA | 0.2 mm |
SLS | 0.2 mm |
Material Jetting | 0.1 mm |