HookOn system for SKÅDIS

Introducing the versatile SKÅDIS HookOn system 

– featuring locking slide-on hooks to achieve supportless printing, stealth appearance (completely hidden!) and tiny footprint to ensure they fit in almost any project.

Usage and background

The SKÅDIS HookOn system was borne from a need: a stealth mounting system that is completely invisible when mounted, is solid, and that has replaceable hooks. It is heavily inspired by the Ultimount by @davidmakes, borrowing the main functioning principle from it with these main changes:

1. Easy to use: provided with the HookOn are tested sizes of hooks to get a good fit on your particular printer
2. Easy to incorporate: provided are .step files of everything, together with a positive and negative tool to incorporate the slot into your projects
3. Strong and optimized: the hook itself is perfectly sized to the slot all-around and devoid of any stress risers, ensuring maximum strength and good printing orientation.
4. Simple: the locking geometry is simply a chamfered button: easy to replicate, easy to adjust and optimally strong.

Included in the print files you will find a .3mf test print that will help you find the optimal fit for your printer or a sample container if you'd rather print something useful from the get-go. There are three sizes of hooks available:

• Standard: the recommended starting point for most printers and materials
• Tight: good for more optimized printers and/or for slippery materials like PETG
• Extratight: only if you find the above two too loose!

The test print incorporates all of these into one file, which I suggest to print with your normal settings/whatever you would use for your finished SKÅDIS accessory.

When you have figured out your optimal Hook size, you can simply use the provided Slot and Slot Negative Stamp files to Boolean the receptacle into your mounts. The depth of the slot is about 3mm, therefore the recommended wall thickness is around 5mm, though 4mm will still work. You need about 30mm of height to incorporate the entire slot, however it is possible to leave the bottom of the slot open if you so choose – diminishing the required height to only 15mm or so.


Print everything in the suggested (per the file) orientation!

Limitations

This system was designed over some weeks and a bunch of iterating on my printers, with my filaments, with my profiles and on my white SKÅDIS board. While the Hook/Slot interface has been confirmed working by another user, I cannot guarantee a perfect fit for your particular usecase. It is my understanding that the unpainted SKÅDIS has different dimensions and as such, the current iteration of the hooks might not be perfect for it. I'd urge you to let me know how it fits and help me provide a version of the hook for the unpainted boards!

In all other cases – the .step files are there and available for your convenience. Tweaking the Hook/Slot interface fit is mostly done by changing the width of the hook: 

Summary and thoughts on other systems

I set out to create a system that would allow me to replace hooks when needed/broken, print them unsupported, that would be invisible when mounted, and that would be solid when on the wall, and I feel like I achieved all of these. To my knowledge, there isn't any other SKÅDIS attachment system out there that accomplishes all of these tasks:

• T-clips by @LineArcLine: Very visible when mounted, very secure.
• T-nuts by @6d6178: Visible when mounted, needs extra hardware, super secure.
• Ultimount by @davidmakes: Difficult to incorporate due to complicated geometry and lack of files provided.
• Universal hook by CSD_Salzburg: Simply an adapter: loose hook that takes up a lot of thickness out from the board, and doesn't hold mounts very securely.
• Secure Clip System by @mkingery: Very visible, very bulky. Super secure.
• Universal peg by @GabC: Visible, bulky.
• Universal French Cleat Peg by @izzie_394103: Improvement on the Universal Hook as less space is taken, but doesn't hold mounts securely.

…and probably a dozen more that I couldn't find when doing my research.

Regardless, I hope to add to these excellent options with another that hopefully provides value to someone else as well!

And one last note!

If you do end up using this on your uploaded design, I would appreciate if you linked back to this page for the hooks instead of incorporating them directly into your upload. The reasoning is entirely selfish: this helps me accrue Prusameters. Thank you for your cooperation!