The Illusionist Heart Locket

This is my approach at the illusionist heart locket, as a gift for my girlfriend. Many have already made attempts at this, and you can find some here on instructables, and even more on Google, but this one is made completely by me, i have designed and made every single piece of it myself. Because i used whatever tools i had at hand, some features might not be the optimal choice, so feel free to alter the specifications and features as you please. 

I have seen some designs, that required very very tiny parts, that had to be extremely precisely made, but since i do not have access to neither laser cutters nor CNC machinery, i decided to make a simple design, that i would be able to make, without having to invest in additional tools or materials. I am pretty tight on my economy, so basically anything expensive was ruled out. I also set the criteria that the picture had to be centered, not on either half of the heart, which actually later lead to accidentally figuring out how to put 2 images in the locket. 

Again because of my limited selection of tools, i decided to not make this a necklace pendant, but a 5*10 cm box instead. This was the only way so far that i could get the dimension relations as a wanted, and still have a decent size picture in the middle. It is still small, and has a nice size, fits nicely in the hand, and after several steps in finishing it up, it ended up having a bold and soft surface that i am very satisfied with. 

I have uploaded this in the Valentine's Day contest, so if you like the project please vote for me :)

I spent many many hours designing this locket in solidworks, a program that i legally use as part of my school. 
The locket consists of 4 primary layers, each with 2 slices, an axle, with 2 "sleeves" a custom made pin, and 18 tiny magnets, as seen in the picture (the magnets are not in the picture). Each of the 8 slices are different, and individually made. I have included some screenshots of my working drawings, but more on those later. The complete set of drawings that i used, is attached in a zip as .pdf, and they are all 1:1 if printed on A4 paper. 

To be able to keep track of the slides, i decided a way of numbering them, which also can be seen in one of the pictures. It is made so that when you view the locket from the front, the 4 upper layers are labeled 1.x, where x is 1-4, starting at 1 for the front layer. The lower 4 parts is the same, only 2.x instead of 1.x. This is very useful, when making the parts, to keep track of them, and make sure everything gets done right, and none two are mixed up.

I will try to explain how it works, but please take a close look at the pictures, they might help understand it. 
The pin, that has a orb at one end, and a corner at the other end, is the axle that the entire lower part turns about. The round end can turn freely inside the two middle layers 1.2 and 1.3, which are glued together, whereas the corner end cannot turn inside the layer, forcing the pin to turn around, together with the lower middle layers, 2.2 and 2.3. On the large circle in the middle of the pin, an image can be glued on either side, and thus in one position the first picture will show, and in the second position, the second picture. The magnets are there to secure the parts in the positions that we want. 

If the pictures i have attached is not enough to fully understand how it works, please let me know, and i will provide some more. 

For this project, my most used tool was my dremel multitool. It can probably be made without one, but i am quite sure that it will be a very very long process. Additionally i have used 
- Bandsaw (not essential, but faster)
- Rotary sander (anything that can remove material at a 90 degree angle)
- Drill press (You need to be able to make fairly accurate holes)
- Stuff for silver soldering (Not essential, that is just the way i made it)
- Waterbased wood glue (very important)
- Superglue
- Appropriate size drills


For materials you can either decide what to use and buy that, or you can see what you have lying around. I, because of my very tight budget, went with latter. The wood i used is teak and birch, but that was just because it was what i had. When you choose wood for this project, make sure it is some hard wood, ceder is for example not hard enough (I'm guessing). This is because of the amount and size of detailing. The axle is made of birch as well, and the sleeves are some carbonfibre tubing i had in my basement. The custom pin that serves as an axle as well is 1mm silver wire. I had it lying around, and since i know how to silver solder, i decided to make it that way. Silver is not at all optimal, because it is so soft, and there is a way to big risk that bends or breaks. If you can find another way of making the pin, i would advise that. Please let me know if you have any ideas. 
I also ordered 20 disc magnets from supermagnete.de in the dimension Ø3x1mm. 
And of course our friend, the sandpaper. 

The first thing that i did, was to get my blanks. I only had some rough blanks, so i had to plane them down to the right thickness first. In my project, they are 5mm thick, so the assembled locket will be 20mm in total. The edges are not so important, as they will be worked over later. Make sure you have enough of your blanks to fit at least 8 (it's nice to have a little extra, if somethings goes haywire) slides on to them. 

To make the slides, i printed out all my drawings 1:1, and cut them out. Make sure you keep track of the numbers of them, it is very important that they are not mixed up. My drawing show the slide from the front, back, and from the face that are going to be the plane in witch it turns to switch between oval box and heart. I now glued (with waterbased woodglue) the pieces of paper to my blanks, so i could start shaping them. I only glued the paper drawing to one side, and i used for each piece the side that would be the front of the slide. This is a little tricky to explain, i hope you get where I'm heading. Remember to also consider how the lines in the wood will align when they are turned around. 

With the paper in place, i started cutting the pieces, first roughly on the bandsaw, then a little closer on the bandsaw again, but with more easy to handle pieces, and finally on the rotary flap sander. On the flap sander i sanded them down, until i just hit the paper. (remember, you still only have paper one one side of the wood). As you can see in the picture, i have a piece of plastic under my slide when I'm sanding it. This is to avoid scratches and smudge from the metal base it is lying on. 

When that was done, i had 8 almost identical pieces, except for the paper of course. 
To make sure the diagonal surface was very flat, and would fit its counterpart i set up a little jig, to sand them down to a nice flat line. It was really just a piece of sandpaper on a flat table, and a box with a 90 degree angle on top of the sandpaper. Then i just held the slide to the side of the box, and sanded the diagonal surface. 

Now i was able to glue on the rest of the drawings, because the slide had the final outer shape. I cannot stress enough that you need to keep track of the number if the slide! That was why i numbered them all in the first place. The last image is a little ahead, because as you can see, i already started working on the internal detailing. 

The pin i made is, as said before, made of silver wire. This is not ideal, because the silver is so soft, but it was what i could find. 

To make it, i started our by soldering a ring, with an external diameter that just exactly fit inside the orb shaped hole that we will make in the next step. (18mm outer diameter, 16mm inner dia). Then i soldered up a ring that fit inside the bigger ring, and soldered those two together. This was to add a little strength to the pin, because if it breaks, it is back to scratch. 

With the two rings soldered together, i took a piece of wire, and put it on top of one of the 2.2 or 2.3 layers, where you can see the wire has to have an angle. Then i bent and cut it, so that it would fit in the grove that we will later make. The opposite end has to have a little ball at the end, but before we can make that, it has to be soldered in place first. Otherwise the ball would burn when soldering, so just cut a piece of wire to size, and solder the two to the rings. 

Afterwards i cleaned it up, and polished it a little. When done you will not be able to see it anyway, but just for good measure. 

To make the ball, i took a pushpin with a round end, and pulled off the little ball. Then i drilled the hole up to 1mm, and glued it on to the pin with superglue. 

When the paper is glued on, so that is matches the opposite side as close as possible, it is time for the internal details. By that, I mean the orb shaped hole the pin turns inside, and the groves in the two middle layers that sandwich the pin. I made everything with my dremel, and a selection of different router and sanding bits. When doing this be patient. If you need to change routerbits to make something better, do it. Even if it means changing every other minute. It is not worth it to try and do it with wrong tools, because you are too lazy to change them, you are very likely to either break or damage it, so be patient and make every detail as good as possible. The better you do it now, the better it will look as a final product. 

When making the inner detail i constantly checked the fit with the pin, to make sure i didn't either cut off to much or too little. When you have a snug fit, you can just continue from here, but note that when the paper is removed, you maybe need to make the groves and holes a tiny bit larger. 

For the axle it would probably be easiest to find something that already is the 3mm you are shooting for. However i couldn't find anything, so i had to make one. To do this, i put my drillpress on the side, and used it as an improvised lathe. I found a piece of fairly straight wood, and started turning it down with a wood chisel. When i was close to the 3mm, i got my caliper and fixed it at 3mm. Then i slid it down over the axle, removing the last bits and making the axle a nice uniform thickness all the way through. Make sure that you end up having more than 20mm axle, the excess will be cut off later. 

The sleeves that go over the axle in both ends is made from a carbon fibre tube, that i had from an old kite, and it happened to fit perfectly. Make sure these also are more than the 3mm tall that it is going to end up as, it is way easier to remove that create material. 

It is also a good idea to drill the holes in the slides that the axle are going to sit in by now. That way you can test the fit, and make sure you don't make a too small axle. You want a close but free running fit. 

The magnets i used is from supermagnete.de, a German website dedicated to magnets. I am very satisfied with them, and can highly recommend them. 
The magnets are small discs, 3mm in diameter and 1mm tall. You need 18, but it is nice to have some extras if you loose one or two.
To set them in place, i took a 3mm drill (surprise :) ) and drilled very small holes where it said so on the paper. I tested the depth for every hole, to make sure it would end in the best possible depth, 1mm of course. The middle layers were tricky, because the magnets are going to sit in both 1.2 and 1.3, and 2.2 and 2.3 at the same time. To make those holes, i sandwiched them together, with the pin in between, to make sure the were properly aligned. Make sure when drilling that, if your vise or whatever you use to hold it together applies pressure all the way up to the edge of the two layers, where you are drilling the hole. It is important, because otherwise the two layers might be pushed a little apart, and the magnet will not fit in afterwards. 

Note! Do not glue any magnets in place yet! Drill the holes, and then see next step before gluing the magnets in. 

Now for a lovely messy part. Cleaning it up. Remember how i went off about waterbased woodglue? Here's why. 

To get the paper off the wood, simply grab a small clean sponge or towel (it will be a one-time use), dip it in water, and start rubbing. The waterbased glue will dissolve, and you will be left with some water, paper and glue mixture that can be wiped off. Remember to clean it well, so that there is not a layer of glue when you are done. Also don't use too much water, just enough to dissolve the glue. 
After cleaning them, you need to revisit your internal details. They might need to be redone a little, because the paper is removed, but also because the wood has been wet, and it might effect it. Same thing goes for the holes you have drilled, both for the magnets and the axle. 
Remember that before redoing anything, make sure the slides are completely dry first! 

In this step we are setting the magnet in the holes we made. I used superglue to hold them in place.

To get them all the way down i the hole, without using my fingertips (nasty superglue..) i used the backend of a 6mm drill. This enabled me to set them perfectly flush to the surface. 

Here's a little hint......
KEEP TRACK OF POLARITY!! this is very very important! The way i did that was to have all magnets in one line, and then picking them as i needed them. It is a little hard to explain, but easy to understand why it is important, so find whatever way that is easiest for you. 

(Wait with the 4 magnets that are going to sit in the middle layers, facing their upper or lower counterpart until after the next 2 steps)

Now it's time to decide which pictures you want to have in the locket, if you haven't already done that. I picked my girlfriends favorite picture of me, and my favorite picture of us together. I would advise to pick some meaningful pictures. This project, given the amount of time and effort you put in it, is worth it, and deserves it. 

Printing them was for me difficult. I had a lot of difficulties getting them out in the right size (18mm diameter), and ended up just printing one, measure it, adjust, print, adjust, print and so on. The final images are printed on photo paper, to get the best quality possible. 

When printed, cut them out and glue them on the pin. I used superglue again here. Make sure you angle them right, so they aren't off when you view then in the finished locket. 

Now for the exciting part.
It can be tricky to assemble the pieces, because if you get it wrong, it might not be able to turn around. I had to be especially careful since my pin is made of silver. If something gets stuck, it might very easily bend the pin and the whole thing is ruined.

The 4 middle pieces, 1.2 1.3 2.2 and 2.3 are going to sandwich the pin, so those have to be glued. I decided to glue piece 1.4 to 1.3 also, to avoid the possibility of viewing the wrong photo. The pieces 1.1, 2.1 and 2.4 may absolutely not be glued to anything! They are the parts that are going to swivel to reveal the pictures. Also remember to put the pin in! That would really suck to forget :)
Before gluing them together, I treated the wood with mineral spirits and linseed oil with a swab, but only on the sides that are not going to be glued later! This is just a first-treatment, because some areas might be difficult to reach later, and you have to be careful treating it when the pictures are in. I used a 1:1 mixture approximately, the linseed oil makes it look neat, and the mineral spirits allows it to be absorbed better in the wood. You are going to finish the locket with sandpaper later, so this is not a final treatment.
When gluing it, I used a swab to spread a thin layer of waterbased woodglue on the sides that were going to be glued. Apply glue to both sides, but keep in mind that it will flow a little when pressed together, so make it a nice thin layer. I put the axle in to match alignment, but took it out when the layers were set away to cure. When the pin is in and the sides glued, check that it can spin as you want it to, and that it is aligned properly, before setting it away under pressure for at least a few hours.

When the 5 slides that are glued together are done, it is time to insert the axle and the sleeves. This was a tricky part as well, because you don't want to glue it all together so it cant open. My way to do this was to spread a layer of superglue inside a sleeve, and gluing it on one end of the axle. When completely dry, i inserted it in the 4 layers. Then i put a drop of glue in the other side of the stack, where the axle is sticking out, and put the sleeve in place. This fixes the whole thing in one side, but it is still able to turn, because the other sleeve is only fixed to the axle. It's tricky, so be careful. 

By now you should be left with an almost finished locket. To finish it off, I first cut the axle and sleeves down, and filed them down to sit flush to the surface. Then I sanded the outer corners, (only the outer!) with some 220 grit sandpaper. When I was satisfied with the shape, I polished it with 600 grit sandpaper, and gave the outer surface a final treatment of mineral spirits and linseed oil. It, apart from improving looks, also gives it a soft and comfortable feel, and I personally think it smells fantastic.
And that’s it! You’re done! All that’s left is to give it to whoever you made it for. I am thinking of making a nice box to put it in, but time might not be on my side.
Once again please vote for me in the Valentine’s Day contest, if you like the project. Also please leave a comment, if you have any questions, or just feel like commenting. I am open for suggestions of improvements, and I am always happy to learn.