Curving Hammer

1 May

Week9 and Week10 Mechanical Design; Group project; useless machine

In the group work, I mainly designed a curved hammer, a cap for the button and the top for the box.

The group page is: ultimate Useless Machine

The hammer is used to hit the button to its original place. One side of it is tied to the servo and it rotates with it. Another side is used to knock the button. I designed it in a 2D form then I lazer cut it. We tried it on both acrylic and wood. The challenge is to minimize its weight so that the servo would have enough power to drive it. However when the material is too thing, it breaks easily. In the original design, I used a paper clip to get a rough shape of the hammer. When I laser cut the first ones I tweaked a bit either to the head design or the length of the arm. After decades of tries, we got a final one that fit the machine perfectly.

Here's a screenshot of hammer designs with different angles that I tried laser cutting to get the best angle and size.

The design file can be found here: hammer_adjustedsize7.ai

Button Cap

The cap is used to enlarge the surface for the hammer to hit upon. I designed it with a hole so that it can be capped onto the button. We want to 3D print it. The challenge is to make the hole fit and do not move or rotate. The diameter of the button is 4mm. Considering the measurement error and the shrinkage of a 3D-printed product, I tried different design from 3.3mm to 4.5mm. Finally the 4.2mm ones fit.

The STL file can be found here: button4mm.stl

The designL file can be fetched here: button-cap.f3d

Box Top

I designed the top of the box according to my colleagues' design for the sides. I took the length for each tooth as the edge on top and took into account of the range of positions that the servo moves.

Here's what my colleague had designed.

This is my design of the top. It was based on my colleague's design of the sides. To match each gap on his design on top which was not parametric was a challenge in this task

The 2D design can be found here: usedbox_top.ai