Repairing a screwdriver with 3D printing + torque test

In this video I am repairing a screwdriver but not because I desperately need it, but because of the challenge, I would like to see how big torque can be transmitted between metallic and 3D printed part. I will 3D print a test probes and measure the torque and based on those results I will create a final version. This information will be useful to me, when I am designing other 3D printed parts for attaching to metallic objects (like gears to DC motor shafts).
Contents of the video:
0:00 In this video
0:08 Introduction
0:33 About torque
2:58 How will I measure the torque
3:32 Aim of this project
5:25 Designing the test object(s)
9:23 Measuring the torque
11:00 Designing the final screwdriver
13:54 Testing and using it
16:10 Conclusions

Materials and methods:
3D Printed on Prusa MK3 using PrusaSlicer and Prusament PLA filament. Layer heights, infill variable, shown in video. Designed in Fusion360.
Measured with simple kitchen- and 40 kg hanging scale.

My Patreon page:

[JohnJones-oymd]

Very useful info. I love your methodical approach to testing.

[oecypher]

This was very helpful thank you my friend

[ignacioasiain]

Que buen video amigo. Saludos desde Argentina

[TheOomen]

Try heating the old screw driver with a blowtorch. and design the insert in the 3d printed part a few mm smaller. When you insert the shaft of the old screwdriver the, shaft will melt the inside of the printed part and make a secure fit. This is easier than your method, but I think your method will be more secure

[partsdave]

Here also. Prusaslicer will put filament changes in for you in the Slice preview screen. The plus + button on the slider.
Just reslice after.

[Spartacusse]

According to CNC Kitchen's findings, you'll get a much stronger part as well as print a lot faster, if you reduce to infill to say 20% and increase the perimeters (walls).

[brawndo]

7:20 I invented a trick to strategically increase the number of walls on a model. If you cut a 0.1mm slot offset by [line-width * perimeters] you can trick the slicer into giving you extra walls anywhere inside your model. I used this to increase torque of a critical embedded hex nut.

[avejst]

Interesting. I would love you to test the finished screwdriver in your torque tester
Thanks for sharing :-)