How to Design a "Hole Shape" for 3D printing

Today, we will share some tips that users need to know when designing hole shapes for 3D printing with accurate dimensions and positions.


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Great to have you back.

In this post, we will take the time to learn how to design a hole shape when using a 3D printer. 


Droplet or Rhombus Shape (Instead of a perfect circle)

It's recommended to print the part lying down on the print bed when the user needs very accurate dimensions of the hole shape.

However, in case the part needs to be printed with an upright position, we have listed possible options that users can consider:


1. Droplet shape

As shown in the below figure, if you print it out in a perfect circle shape, the overhang angle decreases as the nozzle goes up in the height direction, which results in deflection.

fabWeaver sample printout design with circle shape

Printout designed with perfect circle shape


In order to prevent this, it is recommended to design parts with a droplet shape instead of a circular shape.

As the print gets closer to the Z-axis, the overhang angle will be greater, preventing deflection.

fabWeaver sample printout design with droplet shape

Printout designed with droplet shape


2. Rhombus shape

If the user designs a printout that will be assembled into other 3D printouts, it is better to design the hole in a rhombus shape.

The rhombus shape can be printed with an inclined plane at a 45-degree angle overhang without deflection.

Therefore, it can be accurately assembled under properly given tolerances.

fabWeaver sample printout design with rhombus shape

Printout designed with rhombus shape


Consideration when designing tapping holes

When the user designs and prints by tapping the hole to couple the screw, a too-small diameter screw thread can cause failure while printing, and even support can be generated between the screw threads overhang.

fabWeaver sample printout design with screw thread shape

In this case, it is recommended, to design the hole with a droplet or rhombus shape first and print, proceeding by making a tapping hole with a tool.

In the process of designing this, the slicer setting needs to be considered, especially wall thickness.

FFF 3D printers fill the inside of the printout with a predefined infill pattern, but a low infill density can cause damage or breaking on the printout while making a tapping hole.

On the other hand, an increased density can result in more material consumption and extended printing time which is negative for productivity.

Adjusting the wall thickness or wall line count setting of the slicer can resolve this issue easily.


fabWeaver Weaver 3 Studio slicer wall setting

Wall setting items of Weaver 3 Studio slicer

As shown in below sample design, an increasing number of wall lines on the slicer will increase the density around the hole, allowing for stable tooling to make screw threads.

fabWeaver sample printout design with wall 2 lines setting

Setting 2 for wall line count value (default setting)

fabWeaver sample printout design with wall 8 lines setting

Setting 8 for wall line count value


Different printing settings can be adjusted and applicable through the Weaver 3 Studio, we hope you have a chance to check it out!



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