I got my inspiration from LasVegas and his instructable for Real Thumb Drives https://www.instructables.com/id/Real-Thumb-Drives!/
My usb bluetooth dongles case broke and I needed something to cover it up.
I decided to make cast of my finger so I could merge it with the usb. Here is the tutorial how to make yourself a thumb usb.
Difference in making this finger is that this one doesn't require instaMOLD which is very easy molding substance. This will also be expensive because you need to get a lot of supplies.

Step 1: Getting Supplies!

Things I needed for this instructable:
- Quickform molding substance
- Plaster
- Silcolan NV (kind of silicon mold)
- 2-component epoxy glue
- Red, green and blue acrylic paint or skin color paint
- Disposable plastic cups
- For example a cardboard box (size of your finger)
-Usb memory stick or similar

You might find these supplies in any hobby or hardware store.

Step 2: Making a Cast of Your Thumb

For the cast I used quickform. Pros in using quickform is that it dries fast and it's toxic free, con would be that you can use the same cast only one or two times because the casting result gets worse every time.
First you need to take out your plastic cup. Divide the cup to four pieces and pour one part of quickform and 3 parts of water to the cup. Mix it for about five minutes. Apply some of the mixture to your thumb before you stick it into the cup .
Now take a good position on the chair, stick your thumb into the cup and try not to move it for 5-10 minutes. [picture 2] Try to poke the surface to see if it has dried. When you feel ready, waggle your thumb out of the cup and the cast is ready!
If your not going to continue straight away, wrap the cup in cellophane

Step 3: Casting - the Fun Part

Simply take a plastic cup, fill it with plaster materials (1 part water, 3 parts plaster), mix well and pour into the thumb hole.

Watch it dry and take out the thumb. Wrap it towel and let it dry for a day.

Step 4: Making a Cardboard Box

Cardboard box should be so big that it fits the plaster finger inside and leaves room couple centimeters in horazontally and vertically.
I think hot glue is the best option for this.
NOTE (look picture): When all the other walls are glued except WALL1 glue the plastic thumb to the opposite WALL2. After that finish the box.

Step 5: Silicone Part

Now this is important part of this instructable.

Ok then take again a new plastic cup in which you put the silcolan NV. I needed 100g of silcolan. It really depends on how small box you made. Silcolan needs only 2% of the hardener so 100g of silcolan needs 2g of hardener ( 2g is about 80-90 drops).
Mix the materials in the cup.
Important note: You should drizzle the thumb with vaseline before you pour the silcolan into the box.

Fill the box to halfway of the thumb and let it dry. The silcolan dries between couple of days to eternity depending on how much hardener you used.

Once it's dry make another 100g of silcolan and fill the box.

After it is fully dried remove the box by tearing it apart. If you'r lucky and you did the vaseline part well you should be able to detach two sides of the mold and the thumb from each other. I wasn't so lucky so I had to break the thumb into pieces and it ripped some of my mold with it.

Step 6: Fill the Hole

Gratz! You have now created a mold of your finger.

For this step you'll need the usb device. You need to take the usb part out of the case so it can fit into the mold.
Once you have the bare usb stick you'll need to look at the pic 2. You need:
-the mold in step 5
-two wooden pieces
-construction clamp and a wooden clamp or similar

The two wooden pieces and construction clamp keeps the mold together and you use the wooden clamp to keep the usb on its position.

Now you have to make the colour and glue mix for the filling. For the colour I have in the cup is the following:
-40 drops of yellow
-12 drops of white
-1 drop of red
After you mix the right colour mix the 5 min epoxy with the color. Once you have the sticky substance pour it into the mold. Watch out so it doesn't go over the edge,

Step 7: The Final Touch

Now the glue has dried so you can remove the clamps and depart the mold pieces. Some of the mold may have stuck to the finger so you need to wash it under water.

You could leave it to this stage but a severed finger doesn't come without blood. Just tape the usb part and paint it red. After the paint dries, remove tapes and paint some runoffs so it looks cool and awesome.

Now amaze your friends and hope you liked my first instructable. Commentz plz!