A simple parallel gripper designed for easy integration with either a sg90 or mg90s servo. Its being used in my bachelor project, which is about attaching a small robotic arm to a drone. The parallel grib isn’t truly parallel, since the projects aims to handle objects that are 25-35mm in size, so the grib opens a up until 35mm and then insnares afterwards, properly gripping the object.

You can use the 20x20mm pad in the back to attach the gripper to whatever you want. the holes are all 5mm from the edge and are designed for m2 screws to slot right through for easy attachment.

For assembly m2 18mm nylon screws was utilized, since it mixed well with the filament, but it can make it hard to see the screws properly in the images.

Printables:

• 1x ServoGripperv2nut (0,2mm layer height) strength
• 2x Gripperjointv2 (0,2mm layer height) strength
• 1x gear1(servo) (0,12mm layer height) fine
• 1x gear2(screw) (0,12mm layer height) fine
• 1x gripper-arm_nut (0,12mm layer height) Gyroid infil
• 1x |mirrored y| gripper-arm_nut (0,12mm layer height) Gyroid infil

Parts:

• 9x m2 nuts
• 7x m2 screws with at least 18mm length.
• 2x m2 screws with at least 8mm length. (for attaching servo).
• Sg90 or mg90s servo (with included screws)

Assembly:

• Place m2 nuts in all the m2 slots of the main body of the gripper and the “fingers”. This can be done easily my pressing the in against a flat surface like a table and then pushing them further in with a screwdriver or something similar.
• Attach your servo using m2 screws.
• If your servo is position based and not “continuous”, I would highly recommend you setting it to its 0-position using whatever controller you’re using.
• Attach gear1(servo) to the servo at a wide angle compared to the main body, see images for reference.
• Attach gear2(screw) to the pillar opposite the servo with the same but inverse angle as the one attached to the servo, see images for reference.
• Attach the gripper joints too the remaining 2 “pillars” as seen on the pictures.
• Final attach the gripper fingers and you’re done.

After finishing you can manually test what the limits of the grib should be. If you’re using Arduino use the servo-sweep example but start out with changing both instances of 180 are changed to something like 50 and slowly increase it until you get the required grib profile. And remember to use a proper power supply and not the Arduino’s power supply, you can destroy your Arduino if you draw too much current.