Strum Hardware Screws
Gather the following hardware for creating the strum mechanism.
- 4x M3 x 10mm pan head screws
- 4x M3 hex nuts
Insert a screw through the bottom of the pick-mount.stl part. Place one of the pick-hinge.stl parts on top of the standoffs. Insert and fasten an M3 hex nut onto the thread of the screw.
Secure Hex Nuts
Repeat the process for all four standoffs. A pair of needle nose pilers can assist in grasping the hex nuts for a secure fitting.
Install Joints to Pick
Install the two pick-joint.stl parts into the pick-base.stl by inserting them from the inside. The flange should be flush with the inner wall of the pick-base.stl.
Hot Glue Joints to Pick
Apply a moderate amount of hot glue to the inside of the pick-base.stl. This will prevent the pick-joint.stl from being pushed in and secured in place.
Install Pick to Base
Begin to install the pick-base.stl part into the pick-mount.stl. Fit one of the ends into one of the pick-hinge.stl parts. Flex the pick-mount.stl slightly to allow the second pick-joint.stl part to fit into the second pick-hinge.stl.
Double check both ends are installed properly. The pick-base.stl should rotate freely.
Parts for Micro Switches
The two micro switches need 4x M3 x 16mm long machine screws and 4x M3 hex nuts. The switches will be mounted to the pick-plate-sw-left.stl and pick-plate-sw-left.stl parts.
Secure Switches to Plate
Place one of the micro switch onto either of the pick-plate-sw parts. Orient the micro switch so the mounting holes are lined up with the plate. Insert one of M3 x 16mm long screws through the micro switch and plate. Insert and fasten an M3 hex nut to secure the switch to the plate.
Repeat this process for the second micro switch. Double check the orientation of the switches are matching with the photo.
Wires for Micro Switches
Use the following wires for connecting the micro switches.
- 2-pin JST female cable – 114mm long
- 4-wire ribbon cable – 180mm long
- 2x 2-pin JST male connectors
Separate the 4-wire ribbon cable so there's 2x 2-wire cables. Use wire strippers to remove a bit of insulation from the tips of each wire. Tin the ends using a bit of solder – This will prevent the strands of wires from fraying. Third helping hands can help assist while soldering.
Wire JST Connectors
Solder up the 2-wire ribbon cables to the male 2-pin JST connectors. Don't forget to add heat shrink tubing before soldering – This will insulate the exposed wires and prevents connections from shorting out.
Micro Switch Ground Wire
Solder one of the wires from either 2-wire ribbon cable to the common ground on one of the micro switches. The ground is labeled on the side of the micro switch "COM". Tinning the pin of the micro switch can help solder adhere to the wire.
Wired Micro Switches
Repeat this process for the second micro switch. Double check the wires are connecting to the correct pins and have solid connections.
Get the parts for the strum assembly. The mounting plate, micro switches and pick base. This will need 4x M3 x 6mm long screws and 4x M3 hex nuts.
Install Strum Mounting Plate
Insert 4x M3 x 6mm long screws through the back of the guitar body. Use the four mounting holes in the center near the middle of the body. While holding screws in, place the pick-mount.stl part over the screws so the threads go through the four mounting holes.
Install Micro Switches
Place the two (pick-plate-sw-left.stl and pick-plate-sw-right.stl) micro switches over the threads of the screws. Reference for the photo for correct placement.
Secure Strum Parts
Insert 4x M3 hex nuts onto the screws and fasten tightly to secure the strum assembly to the body of the guitar.
Install Pick to Hinges
Fit the joints on the end of the pick-base.stl to the hinges on the pick-mount.stl. Start by fitting one end and then the other end. The parts can flex slightly to offer more clearance for the joints to be fitted into the hinges.
Test Strum Pick
Test out the micro switches by rocking the pick back and forth. The levers should easily be pressed. The pick should stay in the center when idle.