Loading

Hinged Chest with Working Lock and Wood Texture

by DrLex, published

Hinged Chest with Working Lock and Wood Texture by DrLex Feb 22, 2018
11 Share
Download All Files

Thing Apps Enabled

Order This Printed View All Apps

Design Tools

Blender

A part of these Groups

View All

Liked By

View All

Give a Shout Out

If you print this Thing and display it in public proudly give attribution by printing and displaying this tag.

Print Thing Tag

Thing Statistics

7572Views 2207Downloads Found in Containers

Summary

My godson has some kind of obsession with collecting small things in small chests, and he wanted a chest with a working lock. So, for his next birthday I took athey's Small Hinged Treasure Chest and designed a lock mechanism for it. Of course it is the most basic lock possible with only one possible key, and picking it is trivial, but it is functional.
I also spiffed up the overall looks of the chest with extra details, like the excellent wood texture from the OpenForge Wooden Floors by devonjones.
The hinge has been made slightly beefier to reduce the risk of it breaking.

To unlock the chest, rotate the key counter-clockwise and open the lid while keeping the key turned. The lock cannot be left in the open position, closing the chest automatically locks it. This video demonstrates how the chest works.

I made three different key designs, although the skull key will probably be the most popular with little (and big) children by far :)

Assembly is rather straightforward, but the parts must be printed and mounted accurately for the lock to neither fail to close, nor be sloppy. See the images for instructions. On a well-calibrated printer, the parts should only require minimal post-processing to make them fit. If your prints tend to be sloppy, some extra sanding and scraping may be required. See the post-printing section for more details.

The dimensions are 76 × 46 × 57 mm for the bulk of the chest, and 76 × 51 × 58 mm with the hinges and details included. It should be possible to scale up the model, but you may need to scale up the latches a tiny bit more in two of the three dimensions to keep them a tight fit.

Print Settings

Printer Brand:

FlashForge

Printer:

Rafts:

No

Supports:

No

Resolution:

0.1 mm and 0.2 mm

Infill:

20%


Notes:

Supports should not be needed. Even though the dome of the lid has overhangs that go beyond 45°, those overhangs are actually printed as bridges, therefore if your printer passes the bridge torture test, you do not need supports.

The chest and lid were printed with 0.2 mm layers in rigid.ink ‘Pearl Red’ ABS. I used a brim to avoid warping.
The latches and keys were printed with 0.1 mm layers and 3 perimeters. It is important to print these parts with thin layers, to ensure they have an accurate thickness. You should also print them slowly to ensure the latches have an accurate shape.

If you print this with a rather flexible filament like PETG, the lower latch may be too flexible, and you may need to print it in PLA or ABS instead for it to be stiff enough.

Post-Printing

Make sure to remove any traces of a ‘squashed’ first layer (elephant's foot syndrome) on the latches and hole in the lid, through sanding or scraping with a knife. Try hooking the latches into each other with your hands: they shouldn't easily slip out of each other. If they get unhooked easily, try to adjust the hook shape with a knife.

The lower latch (long piece) must be mounted in the chest with the hook pointing to the right, and the top perfectly flush with the edge (simply pushing it in on a flat table should do the trick). If you cannot push it deep enough, scrape off some material from the bottom end.
The latch in the lid must have its hook pointing to the left, and ideally the edges of the square part should be flush with the bottom edge of the lid. If the lock doesn't catch, you either need to pull this latch out again by a fraction of a millimeter, or shave off a bit of material with an X-acto knife.

If the lid doesn't close easily due to the latch bumping against the top edge of the chest, try sanding or scraping a bit of material from the front edge of the latch.

When printed accurately, the parts should fit tightly enough that no glue is required. The advantage of not using glue, is that the latches will pop out of their sockets if the chest is pulled open with excessive force, instead of breaking and leaving bits behind that are impossible to repair. In other words, you need to make a choice between a chest that is harder to open without a key, but will be broken if someone does manage to open it; or a chest that is easier to open but can be repaired if needed. After all, this is just a toy, not a secure storage device!

If you do want to use glue, do not use cyanoacrylate (super glue) unless you are skilled in using it. It tends to solidify in a fraction of a second, causing the parts to become stuck before they can be inserted deep enough, making the lock unusable.

More from Containers

view more

All Apps

Auto-magically prepare your 3D models for 3D printing. A cloud based 3D models Preparing and Healing solution for 3D Printing, MakePrintable provides features for model repairing, wall thickness...

App Info Launch App

Kiri:Moto is an integrated cloud-based slicer and tool-path generator for 3D Printing, CAM / CNC and Laser cutting. *** 3D printing mode provides model slicing and GCode output using built-in...

App Info Launch App
KiriMoto Thing App

With 3D Slash, you can edit 3d models like a stonecutter. A unique interface: as fun as a building game! The perfect tool for non-designers and children to create in 3D.

App Info Launch App

Print through a distributed network of 3D printing enthusiasts from across the US, at a fraction of the cost of the competitors. We want to change the world for the better through technology, an...

App Info Launch App

Treatstock is an online platform that offers decentralized manufacturing services such as 3D printing and CNC machining for clients all over the world. We offer free and instant access to comparati...

App Info Launch App

3D print your favourite design with NinjaPrototype, a professional 3D manufacture with consistent quality and speed.

App Info Launch App
Comments deleted.

Looking at the lid, if there are no supports used, it would be printed open end up. Since the top is rounded will this cause problems for bed adherence? it seems like it might cause printing problems. if printed flat side down it would appear to be more stable but would need supports for the dome. Suggestions? Cute design. i will try to print it in brown or black. Jolly Roger would be a cool touch.

I don't recommend trying to print the lid with the open end up. The result will likely be ugly unless you're using soluble support material. Moreover, you would need about as much support material as when printing flat side down anyway.
You should be able to print this flat side down without supports, even though the top of the dome violates the typical 45° rule and every automatic overhang detection will try to convince you that you need supports. Supports are not needed because the contours are anchored at both sides, which means they are actually bridges. Therefore if you have passed the bridge torture test, you should be able to print this without any supports, like I did. A cooling fan will help a lot to print these bridges/overhangs correctly. I only saw some minor curling up of the middle of those bridged contours in the very last layers before the top of the dome was sealed, but it was not problematic at all.
If you're in doubt whether you can print this without supports, you can slice the upper section of the lid in a mesh editor of your choice, and print that part.

Bridge Torture Test

The base came out fine. I printed the top, with the flat part on the bed. After about the first 1/3 it has a more "weathered look to it. The very top spline on the inside was the most difficult fro my printer to handle. It is very rough and the filament did not lay flat. i sort of figured this would be an issue. It will take a lot of support material to give it stability, probably more than the actual lid. The little hinges are perfect and snap together well. So is the area for the latch and key. Maybe I will try support material.

I agree. Should not need support to print the top.

Top