Door Hold-Open - Remix

Door Hold-Open - Remix

This is a wall-mounted hold-open device for an interior door. It folds flat against the wall when not in use.

This is a remix of...

Folding wall hook

...posted by iqjocke on April 18, 2020 at...

https://www.thingiverse.com/thing:4296210

The OP's design was for a folding wall hook with the fixed hook end pointed up. In order to adapt this model for my intended purpose I extended the shank length and separated the hook portion giving it the ability to rotate in 90 degree increments, with detents. The base halves and the part of the shank captured by them is unchanged from the OP's design, which is very nice.

With this shank size, the hook engages the door face at about 17 cm (~ 6-3/4") from the wall.

I found a parts box spring that worked for me so I don't know the source nor the exact specs. It is stainless steel and is quite stiff. the spring has about a 7.5 mm OD and fits easily over the M5 threaded rod. The free length is 12 mm. The spring pocket in the shank part is sized for that (8 mm ID, 6 mm deep). Hopefully anyone intending to build this can find a suitable spring.

The M5 rod should be a minimum of about 50 mm long but there's around 50 mm of extra hole length in the shank so anything up to around 100 mm will fit. There are half-hex pockets in the hook and shank to capture the nuts and keep them from turning.

The M5 rod needs to be threaded completely into the Nylock nut in the hook part before assembling that to the shank. I put the hook in a vise and double-nutted the exposed rod to allow using a wrench to drive the rod into the Nylock nut. When assembling the hook portion into the shank, thread it in until the spring compression provides a positive detent action at the interface between hook and shank.

The detents on the mating faces of hook and shank hold the hook in position at 90 degree increments and hold the hook in the desired position securely, either engaging the door face or folded flat against the wall.

I'm pretty pleased with the mechanism for placing the hook at different positions and will keep that in mind for future projects. The detents could easily be made to work at other angles and the positioning is positive and reliable. I think the blind hog found an acorn on this one.

Bill of Materials:

Printed Parts:

- Hook

- Shank

- Wall Hook

- Base (unchanged from OP's design)

- Wall Hook - Top (unchanged from OP's design)

Purchased or Parts Box:

- SS Spring, ~ 7.5 mm OD X 12 mm free length, ID => 5 mm

- M5 Hex nut

- M5 Nylock nut

- M5 threaded rod, 50 - 100 mm long

Printing Notes:

- Material: PLA

- Nozzle: 0.4 mm

- Layer Height: 0.15 mm

- Infill: 16%

- Shells: 1 mm

- Supports: Yes for shank; no for all else.

Design and description by allardjd , licensed CC-BY-SA.