Task 15

Mechanical design

In this week, I was given a task to have a group assignment. The group assignment was to Design a machine that includes mechanism+actuation+automation, build the mechanical parts and operate it manually and document the group project and your individual contribution

Group Task

For this week, I did the group work with Micheal, Alok, Sahan and Jobin. A brief Introduction was being given by our local Instructor, also last year project videos were being domostrated to get an idea of what kind of week this is gonna be in terms of Mechanical Design.

Fig.1 - Team (Writing Bot), Jobin took the picture
Fig.2 - Rough Sketch of the Wrting Bot

We all gathered around and discussed about the possiblities of projects that we can think. Plenty of ideas came and as per initial discussion we though to make an Automated Elevator but as per further discussion and due to its limited practical applications we abandoned the idea. The Next Idea was to make a writing bot that writes something it can draw shape or write a text. All of us agreed to endorse this idea starting giving input interms of design. Our Initial thought about this design was to have 2-axis movement that moving in x and y direction that required two movement mechanism that will use two motors but inorder to provide better stablity we decided to use two movement mechanism i.e x-axis and the y-axis movement mechanism shall be place on top inorder to acquire better stablity for the pen that will be placed on the y-axis mechanism. More details can be found on the group page

Fig.3 - Linear Motion Mechanism from last year to understand the sketch demonstration

My Contribution

We all were taking step by step approach in the design process. Initially the first thing to do was a proper 3D Design of the Writing Bot. Sahan was given the responsiblity to do that with an input of a rough sketch from all of us. After the 3D design done on Fusion 360, the next step was to laser cut the parts individual parts to make a press fit constructions. Since the design made on Fusion 360 was not a pressfit. I took the responsiblity to measure each Linear box of X and Y Axis in fusion 360 and convert them into 2D Inkspace pressfit Environment so that the we can laser cut that.

Fig.4 - Writing Bot 3D Model Mechanisms involved
Fig.5 - Using Inspect-->Measure in Fusion 360
Fig.6 - Taking Measurement of all blocks Involved
Fig.7 - Taking Measurement of all blocks Involved

I used Inspect-->Measure Tool in Fusion 360, to measure all the Linear Motion Mechanism involved and replicated them in Inkspace Environment. In Inkscape, I installed Tabbed Box Maker extension, by simply copying the files to inkscape/shares/extensions folder. Under extension, laser tools, selected tabbed box maker.From opening windows I could select dimensions, tab width, kerf, joint clearance etc. We used the MDF Material 3mm, and the kerf value was 0.145 for pressfit.

Fig.8 - Using Inkscape Tabbed boxes Extension to create pressfit boxes in Inkscape.

Inkspace Pressfit Design : Linear Mechanism 01 (X-Axis)

Fig.9 - Inkspace Pressfit Design : Linear Mechanism 01 (X-Axis)

Inkspace Pressfit Design : Linear Mechanism 02 (X-Axis)

Fig.10 - Inkspace Pressfit Design : Linear Mechanism 02 (X-Axis)

Inkspace Pressfit Design : Linear Mechanism 03 (Y-Axis) and Side Support

Fig.11 - Inkspace Pressfit Design : Linear Mechanism 03(Y-Axis) and Side Support

After the Tabbed Boxes were made and the files got ready, the next step was to Laser cut, the other group members were given the responsiblity to take over and process to the next stage.

Technical Problem: Fixing Y-Axis on top of the two X-Axis

Well inorder to fix the Y-Axis, we decided to fix the Y-Axis on top of the X-Axis with a screw or glue but that doesn't seemed to be a good idea thereby inorder to fix this problem I decided to 3D Design and Print an L joint which shall be used to fix the Y Axis on top of the X-Axis.

Fig.12 - Y-Axis on top of the X-Axis
Fig.13 - L joint Designing
Fig.14 - L joint 3D Design
Fig.15 - 3D Printed L joint fixing Y Axis on top of the X-Axis

Resources Utilized