SwitchHook (V3.1)

Update: 4/15/2020: A new version has been published
https://www.thingiverse.com/thing:4287635

This is a hook tool to assist in opening doors
(inspired by Coolioiglesias' Savegrabber , though it uses no part of its design)

It is modeled with a manual flip-open action, similar to a swiss army knife.
When closed, the hook is mostly enclosed to minimize chance of transferring contamination.

Features

Measures 106mm x 55mm x 23mm (4.2" x 2.2" x 0.9") when closed.

The hook accomodates:

• Round handles up to 33mm in diameter
• Keypads with keys as small as ~6mm
• Lever handles, in general.
• Those push-flap and push-bars things on doors, using the V-groove on the tip.

Hook is not designed for round doorknobs.

Press the button to unlock the hook, which can be flipped open with a flick of the wrist. Do the same to close. Button locks the hook in the open or closed position when released.

Has some non-slip texturing to help pull open heavy doors.

Does not require hardware; center peg is printed and driven in with hammered in. However,a #8 machine screw of 1" or two #8 machine screws of 0.5" may be used instead for smoother flip action.

Print multiple sizes of pegs.

Multiple center-peg sizes are supplied...
Since all printers have different tolerance specs, it is recommended to print them all and pick one that fits.

The intended hole diameter is 4.0mm, and the pegs are supplied in 3.3-4.0mm (does not include 0.4mm increase in flaring diameter). For me, the 3.9mm diameter one worked. Most printers will probably do fine between 3.6mm and 3.9mm. But more are included just in case.

They have flared ends on purpose and are supposed to be a tight fit.The peg not only acts as an axle for hook rotation, the flares are to keep the 2 flat faces of the enclosure apart. Otherwise, they pinch the hook during rotation if you squeeze too hard, and it becomes hard to flip out the hook. Hook should flip out freely with a flick of the wrist while holding down button. If the two enclosure sides are too close and contact the hook, try sticking a screwdriver between hook and enclosure wall to introduce a thin gap.

Warning
Pins, once hammered in, and appropriately sized, cannot be removed. Start with the smallest pin and work your way up, otherwise you will risk a pin that is partially inserted and stuck.

Know issues/areas of improvement for next version.

• requires a support to be cut out of the area between the button cantilever and the rest of enclosure. this can be eliminated with a slight tweak.
• A spacer (in the form of sticking a screwdriver tip or folded paper between hook and enclosure wall may be required to prevent hammering down of the center peg from squeezing the enclosure walls together on the hook, thus locking it together while contacting and making too much friction for the hook to flip open freely. Can be fixed by making center pin flanges (and enclosure holes) and adding spacing piece to be used while hammering.
• Hook lower C of hook is obsolete and doesn't serve a purpose. Can be eliminated to also eliminate need for support while printing this part.
• Walls of enclosure could probably be thinner.

Disclaimer regarding "switch-" name

Sorry, people familiar with knife terminology. this is technically not a switchblade, since that would require it to be powered by a spring. This is closer to a flip-open folding knife in design.

Let me know if there are any mistakes in design. This is a work in progress which I thought is better to be "out there" than perfect.