Chris Lloyd

MAS.863/4.140/6.943
How To Make (almost) Anything
2019

Week 12: mechanical machine design

For machine week, you can look at the team's collective work on this page. I was on “Team Claw” that designed and fabricated the actuator for the device, a claw that grabs and pops balloons.

I was unfortunately out of town the weekend we got started, so I contributed a framework for brainstorming immediately after class to get the architecture shop managers to contribute ideas and help us decide which machine we wanted to make quickly.

Upon my return, the team had determined the general design of the claw and spool for z-axis movement, which had been prototyped with cardboard.

The next step was to create the next version of the device using laser-cut acrylic with an actual servo to test if it worked.

We had a version with a string and dowel that actuated the claw, but we had some issues with the size of servo that we could use on the claw where it didn't extend far enough.

So we made a new version with a rack and pinion. A rack and pinion is a type of linear actuator that combines a regular circular gear (pinion) and a linear gear (the rack). This gave use the desired grip of the claw and added more control to the release of the claw.

When the part was integrated with the design, it worked! We still had some issues actually popping the balloons. Potentially just making the claw bigger might solve this problem.

You can see the full details of the project here.