Crescent Moon Lamp/Nightlight

Introduction

Thankyou for taking a look at what is my first published 3D print design, I hope you like it and it's of use to you, my Daughter was really happy with it and I hope it brings you and your family as much happiness as-well.
 

It is a shell, and as-such some assembly is required before you can use it fully, but you can do as I did and just buy a really cheap set of white low-voltage LEDs (for more details, see Electronics below).

A Soldering Iron will be required and some heat-glue.
 

Printing

The design comes in several pieces to ensure you can produce the design as cleanly and simply as possible, I provide suggested orientations for printing each part below:

1. Shell

Print this side-on with the shorter-side facing the print-bed, you can use some supports to support this edge - I printed this in PLA with 15mm layers.

2. Front

This goes inside the shell, on the edge with the deeper inset - use this to determine which side faces up - the side facing the print bed should end up on the inside of the shell - this can be printed with relatively wide layers.

3. Battery Box

This is printed with the floor of the box facing the print-bed - I printed this with 15mm layers to ensure dimensional accuracy of the holes for the battery lid - I would also recommend NO supports (otherwise it's a bit of a pain to remove the support generated in the hole for the wires in the bottom corner).

4. Back

This is printed with the inside edge facing the print-bed (there is a 0.4mm recess around the inside edge of the battery box, to allow it to locate for gluing - you could use supports, but with them being so shallow, I'm not sure it'd come off that well - if you have a good print-bed surface, you may opt to print the other way up with no supports - again 15mm will allow for nice crisp locating grooves for the battery box).

5. Bulbs

You will need to print 8 of these - I managed to print these without a brim or supports, despite Prusaslicer suggesting they were needed - but try a brim if you have issues.  Again, print as thin a layers as possible, as the backlighting shows the layer lines if you look closely - Print these in a white PLA - ideally if you know of a more translucent white - use that (look at cheaper white PLA's, I had a brilliant one which while would not typically be treated as a good filament, it was great for this ONE particular application (printing LED diffusers)).

6. Battery Lid

Print this outside face to the print-bed, this is because the inside tabs can print with relatively few supports this way.  I printed with supports turned on, but they're relatively easily removed for this part.  Take care with the supports on the tab side of the battery lid - removing them could snap the deformable catch.

7. Battery Holder

Print one copy of the battery holder - I used no supports and a relatively low layer height to maintain detail around the holes. (Note I include the STL for this - it is licenced separately and I also include attribution to the original creator of THIS STL: Heinz Speiss as-per the terms of his licence (CC BY-SA 3.0) which allows redistribution with attribution)

Assembly

Tips:

• I suggest using Cyanoacrylate glue (Superglue) to assemble the parts.
• Heat Glue is suggested for attaching the Switch and ensuring the LEDs remain in the bulbs.
• While heat-gluing - remember too much heat for too long WILL deform the PLA, keep it to a minimum, be VERY careful with the gluegun tip.

Steps:

1. Check the front by offering it up to the deeper side of the shell - glue in all 8 bulbs into the front piece.
2. Glue the front into the deeper side of the shell using a thin line of superglue around the shell (you may have to hold it against the support until set).
3. Check the location of the battery-box against the back piece, test fit it with the lid, you should see it can catch into all the slots, if it's slightly misaligned, it may not catch properly.  Once happy, glue the battery-box in place.
4. Do not put the battery holder into the battery box until it's properly wired up and verified as delivering a voltage to the plus and minus wires.  Wire the battery box (and ideally test the circuit before going further! - NOTE don't solder the switch or leds on yet).
5. Push the battery wires through the small hole in the battery box, using a small dab of heat-glue underneath if required to hold the battery holder into the box.
6. Flip the back/battery box over, mount the switch, using a blob of heat-glue - I would suggest wiring the switch before gluing into place (but check wiring lengths).
7. Solder the LEDs onto the switch and battery positive wire, Slot the LEDs into the bulb-holes behind the front piece - you can get them to rest in the holes if you have normal 5mm LEDs, but if-not, use a blob of heat-glue on each one so that they can't fall out.
8. Temporarily turn the front over, switch it on and make sure you're happy.
9. Glue the back to the shell - Tuck all the wires inside, run a thin bead of Superglue around the edge of the shell, locate the back part and press down until set.
10. The support currently doesn't lock into the crescent, but a little bit of blu-tack (or heat-glue) will allow you to position the crescent at whatever angle you think looks best.
     

Electronics

I don't profess to be an expert in electronics, but I muddled through re-soldering a small set of white low voltage LEDs inside my light - I've included steps below - but obviously check these with someone who actually knows more about electronics.  However given that the voltages used in this are limited to 2 AA batteries, I think you'll be safe if you mess up (it just won't work) just test each step and after each solder joint and you should be ok! :).

Required Parts:

• 8x Low Forward Voltage White LEDs (it's probably simplest to just buy a cheap set of White Christmas LEDs and reuse them - just ensure they're powered by 2 AA batteries!)
• A Switch that fits the hole in the back.
• Bell Wire (or similar) for wrapping the terminals in the battery holder and/or connecting the LEDs in serial.

Steps:

1. Wire the battery holder
   1. Wrap the first positive terminal with about 3-4 turns of wire - I found it easiest to strip quite a length, push it through and using pliers, bend and drag it back through, before repeating - you're looking to make contact with the positive terminal with at least one of them.  I twisted the remaining stub against the outgoing wire to ensure it couldn't come apart, then ran the wire down and out under the spring of the top terminal.
   2. Wire the first negative terminal - same process for this one, but run the wire from the terminal back in the right-hand side hole of the battery bay, up to the top and out of the other side, this wire needs to connect to the second positive terminal.
   3. Wire the second positive terminal
   4. Wire the second negative terminal - again, route the final wire up to the top of the battery bay, the end goal is to have the battery holder positive and negative wires finish at the top right of the box with plenty of spare wire.
   5. Add batteries, check you can see current between the positive and negative wires - if not, check each connection.
2. Seat the battery holder 
   Feed the wires through the battery box hole inside the shell.
3. Add a Switch 
   Solder the negative terminal to the switch - check that the positive wire and the switch provide a current when switched on, and not when off.
4. Add the LEDs 
   Remove any existing battery box, take note of the positive and negative wires - solder the positive terminal to the positive lead of the LEDs - if you have too many LEDs on a prebought set, you may need to remove a few (ensure you reconnect the circuit at the far end!) and then solder the negative lead to the switch.
5. Fix the switch to the back
   Pop a blob of heat glue on each side of the switch and glue it into the back.
6. Fix the LEDs into the front 
   use blobs of heat glue to stick the LEDs into the "bulbs" in the front panel.