PRUSA Nextruder thumb Hexagonal Key with TORQUE LIMITER

Introduction

This accessory will be used in one of my projects currently being developed for the PRUSA Mk4.

What is this for?

This serves to limit the tightening force on the nozzle when it's being changed. However, please so use it with caution, this is a plastic part, 3d Printed and force may vary (Material, print setting, calibration of the printer, etc... 

I am not responsible for any damage that may occur.

• The torque limitation only applies to tighten the nozzle (clockwise); for loosen screw there is not torque limitation.

In terms of quantifying torque, I have not conducted a controlled assessment. Although it's a straightforward task, I simply haven't had the time, or the tool to complete it yet. I'm currently occupied with the Storage Leaf for my Mk4. 

If anyone happens to have a wrench with a torque limiter and could provide me with the values for the two configurations, that would be greatly appreciated. 

Alternatively, another approach would involve creating an arm extending from the center of the hexagon to a length of 250mm. For this arm, we would need to apply a weight of 6 Newton, roughly equivalent to 610 grams.

How to use

The usage is simple: 

• Unload the filament. 
• Increase the temperature of the nozzle to 250ºC to clean any material remains. 
  • You may want to clean the nozzle with a metallic small brush (Danger: Very hot nozzle, don't touch it)! 
    • If you have a silicon sock, be careful, it will be better to remove it first with the nozzle cold.
• With the nozzle cold (below the glass transition temperature of the material you will use for printing the key) and ensuring not to burn yourself; use the key to remove the nozzle.
  • This should be done following the instructions provided by PRUSA.

Printing

There is a part that need supports, in my experience they where extremely easy to remove, but you shouldn't rush this process; it should be done calmly and with some patience. A pair of fine-tipped pliers will help.

Assemblage

To assembly the 2 part, just snap-fit it together, after they fit it won't be easy to disassemble…

Already available for PRUSA…

Storage Tree - Leaf for PRUSA Tools

Storage Tree - Leaf for PRUSA Mk4

What is already available?

Modular Storage Tree	PRUSA Mk2.5 to Mk4 Flexible steel sheets - Project Leaf
PRUSA Nextruder thumb Hexagonal Key	Storage leaf for Prusa Mk4 on its way…

ChangeLog

• (20-03-2024) - Initial release
• (20-03-2024) - Change to the tip of the key to better work with the silicon sock still inserte (smaller diameter on the tipo of the grey part)
• (09-04-2024) - Version with only 1 arm was removed for the description, but still available on the 3mf and gcode for a couple of days.