Welcome to the hardware assembly section!

In this section we will guide you to put together all the components to make the Simple Thimble!


The project mechanics has been designed to be self produced with low-cost FDM (fused deposition modeling) 3D printing


To obtain properly working 3D printed mechanical parts, you may need to file some parts to make them fit together. Moreover, soldering parts is needed to make this project. Always wear the proper safety equipment. This includes safety glasses to protect your eyes from flying debris, a face mask to protect your lungs from fumes, and gloves to protect your hands from heat and sharp edges. Additionally, it is important to work in a well-ventilated area to reduce the risk of inhaling toxic fumes.

Tools Required

  • Soldering Iron

  • Solder

  • Wire Strippers

Assembly Instructions


Some assembly instructions can be swapped without affecting the final result. This is because the order of instructions does not always matter. For example, if two instructions are independent of each other, they can be swapped without changing the outcome.

Step 1: Create the servomotor-pinion assembly - cut and place the servo adapter to the pinion

The first step to build our thimble is to attach the pinion to the servomotor shaft. First, cut the excess extremities of the servo plastic adapter and press-fit it into the pinion.


Step 2: Create the servomotor-pinion assembly - mount the pinion-adapter assembly to the motor

This passage is straightforward, you just need to use the pinion as a modified servo adapter.


Step 3: Insert the rack and assamble with the servomotor-pinion assembly

Once you have the servo-pinion assembly, you can mount the rack in the main box. Then, keeping the rack to its final position (thimble to maximum compression), instert the servo-pinion assembly making sure to engage the pinion as low as possible on the rack.


Step 4: Mount the main cover on

Now you can mount the main cover on top of the main box by press fitting it in place.


Step 5: Secure the servomotor connection

Cheap servomotors such as the SG-90, do not offer quality cabling, so to increase the life of such servomotors it is strongly recommended to glue the cable coming out from the servo chassis to the chassis itself


Step 6: insert the back cover

Now you can insert the connector of the servomotor in the hole of the back cover. You can insert the back cover on the servo but not completely, we need some space for the next step.


Step 7: Insert the velcro strip and the neoprene tape

In the gap we left in the previous step we can now insert the suitably cut velcro strip necessary to secure the thimble to the finger. After that we can add the neoprene tape to the lower part of the thimble.


Step 8: Wear the SimpleThimble!

Now you can wear the SimpleThimble and test if the servomotor works, or with a servo tester, or by programming our microcontroller.


Step 9: Solder connectors to the microcontroller

Our final step is to solder two male dupont connectors to our D1 mini ESP8266 board. Specifically the Ground cable (usually black or brown) and the Power pin (usually red) respectively to the pin G (GND or Ground) and the pin 5V of the D1 mini ESP8266 board. The control cable of the two servomotors must be soldered to IO pins D5 (GPIO 14) and D6 (GPIO 12) of the D1 mini ESP8266 board.


Another important thing to solder is a connector for the battery. The fastest way to go is to cut a piece of stripboard and solder both the battery connector and the power cables of the servomotors to the power pins of the D1 mini board.

battery connector soldered