New Tools Added to the Stretch Tool Share

Hello Stretch Community!

I am a masters student with Northwestern’s MS in Robotics program, and I had the incredible opportunity to intern with Hello Robot this summer working on a case study with the University of Illinois at Urbana-Champaign, the University of Washington, and Robots for Humanity where we brought Stretch into the home of Henry Evans, a quadriplegic, and his wife and primary care partner, Jane Evans. Armed with a 3D Printer, Dycem, velcro, and miscellaneous materials otherwise destined for the recycling bin I teamed up with our occupational therapist, Vy Nguyen, to deploy Stretch and empower Henry to perform daily living tasks independently.

The first tool I designed was a tray to clip onto Stretch’s arm. We used this to help carry kitchen items to set-up for dinner and save Jane from making several trips to the kitchen, but it is also great for holding your XBox controller, mast clamp, and anything else taking up space on your workbench. You can print your very own arm mounted tray from the STL files provided on the Stretch Tool Share.

For moving larger items, we added a magnetic tow hitch on Stretch’s shoulder, which pairs with magnets we attached to a laundry basket on 4 caster wheels. We constructed the tow hitch from a few layers of packing foam between the magnets and Stretch’s plastic shell, held together by painter’s tape. The magnets make it easy for a user to mount and dismount from the payload by raising or lowering the arm, and the strength of the magnets along with the flexibility of the laundry basket allow for surprisingly easy turns and driving in tight spaces.


Another task we practiced was playing card games. A spinning wheel constructed from printed parts and packing foam organized cards so Henry could finally play without a teammate, and Stretch could be used to spin cards into optimal positions for grasping or signaling which card an opponent should take. More details on the tool share.

Finally, in collaboration with Henry himself, we designed a tool for pressing buttons. After trying this task a few different times with other tools, we found that tools obstructing the teleop gripper camera was a major hindrance so Henry sketched out a new idea that he wanted to try. I turned his sketch into a CAD model and after printing the newest iteration, he nailed the button on the first try. This was one of our favorite creations of the summer, and I loved that the end user was directly involved in the design process. This tool is also posted to the tool share.

One thing I especially enjoy about working with Stretch is how creative you can be. With the APIs and open source software, you can hit the ground running prototyping new features and testing out various levels of customization. On the hardware itself, there are threaded mounting points all over the robot and plenty of flat surfaces to velcro or tape attachments. I would love to see what others have added to their Stretch!

Happy tinkering!

Anna Garverick