How to Embed Nuts in 3d Printed Objects

Welcome! In this quick and short Instructable I will show you how to easily embed nuts in your 3d prints.

Embedding is much safer then melting inserts, is much cheaper and gives strong parts too!

1.) A 3d printer and a design

2.) Nuts

3.) Bolt/Machine Screw (optional)

4.) Rubbing alcohol and cotton swabs/balls (optional)

You will need to create gaps in your design of the appropriate size for the size of the nuts you want to embed.

Ensure that you design with appropriate tolerances for your printer. Otherwise the nut bay damage the print/not go in at all.

E.g I want to embed M3 nuts in my design. I will create the design with the tolerances as well as a correctly sized hole for the screw. Look at the image above. Or the video.

(I use Fusion 360(Education License) to design my projects)

Now this is the important part. You will have to make the printer pause at a certain layer so and put your nut in. Then the printer will continue printing over the nut, capturing and 'trapping' it in the print.

To find out which layer you want to pause at, you will have to use the preview in your slicer. You want to stop at the layer that comes just before the roof of the nut cavity. For example if the first Top layer (of the nut cavity) starts at layer 25, you want to pause after printing layer 24. If you are using Cura then you can just use the Pause at Height plugin in Post Processing Scripts to easily pause at the required layer. If you are using Simplify3D then again you can easily modify the G-code file after exporting it or you can use Post Processing scripts.

To modify a Simplify3D Gcode File:

1.) Find the layer number at which you want to stop using slice preview.

2.) Open the exported GCode file in a text editor.

3.) Find "layer x" (x is the layer before which you want to pause)

4.) Insert the following just below/above it:

M25

G28 X Y

E.g If I want to pause after layer 24 and before layer 25:

;layer 25

M25
G28 X Y

OR

M25
G28 X Y

;layer 25

Now save your Gcode file and start printing!

You want to clean the nuts to remove all the grease and dust which would prevent the extrusion to sticking to the nut.

Just dab a cotton swab in some rubbing alcohol and use it to clean the nut. Then thread the nut onto a machine screw so that its surfaces remain clean.

When the print pauses, the head should home (in X&Y axes). If it doesn't, home it manually (only the X & Y axes) and disable the steppers. Move the bed to a comfortable position.

Bring the nuts that you threaded onto the machine screw to its bottom. then using the machine screw as a guide, insert the nuts into the nut cavity and then slowly unscrew the machine screw and remove it, leaving the nut in the cavity. This way, you can insert the nuts without having to touch them directly which would otherwise make them dirty.

You're done! just home the head (X & Y axes) and resume the print.

Just let the print finish.