Gripper with Larger Flat Ends

thingiverse

This is my remix of the excellent Mantis Gripper, designed to automate the tedious task of testing cash dispensers at work using scrap and off-the-shelf parts. A video showcasing this project can be found here: https://youtu.be/ED8kZkMuPWg. To accommodate a larger flat gripping area than the original Gripper, I modified both the large and small grippers, retaining everything else from the original Mantis design. I added screw-on sensor brackets to the ends of the two grippers to house an infrared emitter/sensor combo. A custom stand was designed to attach the gripper to a motorized slide base. Various motor mounts, sensor mounts, belt grips, and other components were also designed. These parts can be used as-is or customized using the 123D design files in the attached ZIP file. The gripper itself is controlled by an Arduino, while the moving slide it's mounted on is run by an Adafruit Motor Shield. The assembly functions to sense when bills are presented into the open gripper, closing it and then moving the gripper rearward on a track before opening it to drop the bills into a bin below. A running bill counter is incremented, and the assembly then moves forward until it hits the limit switch to wait for more bills. This repetitive process takes the place of a tech having to sit and perform this task for 30 minutes at a time. EDIT: On June 2nd, 2017, the first grabber received was so well-received that the techs commissioned another one. I printed it entirely in "Watermelon" PETG from MakerGeeks. A picture of it can be seen in #5. The rubber has held up exceptionally well; no signs of wear are visible after daily use. EDIT: On April 20th, 2018, both grippers have been in daily use for almost a year now with zero problems. The Mantis Gripper is indeed a well-designed beast! EDIT: In November 2019, after two and a half years, the rubber on the first grabber began to show signs of wear, and I'll need to replace it soon. Additionally, one of the Hitec HS-645MG servos locked up after two years but was replaced without any issues. For the gripper, I used a Hitec HS-645MG Servo from Servocity, which has lived up to its reputation as "durable high-torque servo." Although it is a bit pricey, I've had no issues with it running all day long. Print Settings: Printer Brand: Printrbot Printer: Printrbot Plus Rafts: No Supports: No Resolution: .2064 Infill: 100% Notes: I printed all components with PETG for its durability and ease of printing. Post-Printing: I knew that the screws in the pulley stand needed to be adjusted occasionally to tension the drive belt, so I used brass screw inserts. Grainger.com # 4ZU26 7mm insert was used. The inserts were pushed into the holes of the stand using a soldering iron, and it worked perfectly. How I Designed This: I used Autodesk's 123D Design to modify the original gripper files and design the other components required for this project.