Mechanical design

Objectives of the week

  • Group assignment
    • Design a machine that includes mechanism + actuation + automation
    • Build the mechanical parts and operate it manually
    • Document the group project and your individual contribution

What I did

  • Used Gitlab's issue tracker
  • Adapted an open-source syringe pump

What I learned

  • Good practice for open source project documentation and mechanical design

If I had the time to go further...

  • Our machine will already be finished :)

Files and resources

Step 1: Planning and organising the work

This weeks work is fully documented on the fab lab’s page.

The first part of this week’s job was to plan the work! We already decided that we would adapt the 4xiDraw machine for sherification (this is documented on the group pagepage). We are 5 doing the fab academy, and 4 instructors, the first task was to plan and separate the work! After a little bit of whiteboard brainstorming, we agreed to share the work with our strength: a group working on the 4xiDraw, and the other one on the syringe pump. Concerning the repartition of the tasks, we used the issue tracker of gitlab, a great tool for project management! Each task is an issue, and they can be visualized multiple ways: including my favourite: trello-style:

Step 2: making the machine

This weeks work is fully documented on the fab lab’s page. I focused on the physics behind spherification and on the design and assembly of the syringe pump.

Testing the physics

The idea is to make droplets of a specific fluid (sodium + water/ethanol) in a spherification solution (calcium + water / silicone oil) using a syringe. This can be used for cooking or… for soft robotics!

We tested several mix configurations, and here is the kind of results that can be obtained:

Of course, this is more completely described on the fab lab’s page.

Design of the needle holder

I made a syringe holder that can be easily integrated with the 4xiDraw.

Below is illustrated the (very simple) assembly process for the needle holder:

Design and assembly of the syringe pump

The syringe pump assembly process is well documented here and quite simple. Here is an image of the assembled syringe pump: