Week 1: Grow Chamber

Goal: Ideate a grow chamber for my final project
Tools: Sketchpad, Inkscape

Overview

In an attempt to learn something new and prepare for my final project, I decided to use Inkscape to ideate. My original plan was to create a grow chamber for both terrestrial and aquatic organisms.

I usually sketch out my projects on paper to roughly figure out the dimensions, main parts and then focus on the details. For example, I roughly know how I want the heating and cooling systems to be like; in this case, if I want to use thermoelectric devices, I’ll need heatsinks and some method of physically contacting the growing enclosure. With this in mind, I can begin fleshing out the details here of how to interface with the growing enclosure and keep things sealed; this is especially important if I want to raise aquatic organisms in the chamber.

This time around, I used an online sketching app called Sketchpad and began ideating.

Ideation

To start, I focused on the actuation that I wanted to achieve in this system. In Sketchpad, I drew up approximately which systems I would need and how they would be oriented in the grand scheme of things.

Additional hardware could be added for more specific situations:

• A humidification and dehumidifier combo could be added for terrestrial systems.
• For reef tanks, maybe an external filter or doser that can replace elements being consumed.
• Or even better, an automatic water changing system to periodically replace the water inside the tank.

These would all run off of a main panel that has additional power outputs and MCU control.

Going Deeper

With a rough sketch in place, I wanted to try drawing in 2D. I used Inkscape this time around, and first familiarized myself to the tools available to me. I had a lot of trouble in the beginning, since drawing and connecting lines were actually a lot more difficult than I imagined. The nodes need to correctly connect, and even drawing specific angles needs a keyboard shortcut. I spent some time online watching tutorial videos, and then outlined my learning process as I tried to draw different shapes.

Once I had figured out how to draw simple shapes and layer my objects, I began drafting out my sketch ideas. It took me surprisingly long to draw a cube and then to sketch out the rest of the thermoelectric system.

• Layers: One thing that I realized I liked was using different layers for different distinct subsystems. I could use this to separate each module into its own series of shapes. It felt like it was also a lot easier to keep my drawing organized and to edit specific parts of the drawing by using this, since you can toggle drawing visibility.
• Fills: Filling up the shapes I was drawing was tedious because I wanted to make the drawing look 3D. For example, for a 3D cube, I had to click through a collection of edges and then fill, and then do that for each side so 6 times.

Once I finished messing around with the layers, I moved onto a more final draft.

Final Draft

I used the parts I had already drafted as a baseline, which you thankfully can just copy and paste. Then, I added:

• Heatsinks: the actual details for the thermoelectric system.
• Contact plate: As a contact piece for the other side of the thermoelectric modules, I drew out a piece of metal plate with a couple of sides, folded into the right shape.
• Stirrer: Next, I wanted to try adding a movement generator like a stirrer at the bottom of the tank. This came with a stirbar and also a rough sketch of the actual stirrer, which would be some small DC motor with magnets. This I just represented as a rectangle with a circular cutout.
• LED panel: The last thing from my sketch I wanted to try implementing was the LED panel. This took me the longest, since I tried drawing out the LED lens and also the chip with 4 different colors (like a RGBW). This also came with the rest of the panel, and then a little knob that could be the intensity adjustment.

Finally, the only thing I needed to do was order the parts I had drawn in such a way that a viewer looking at my system would see everything in the right order. Luckily this is also very easy with layers! I just needed to swap the order of layers around since this changed the order that they were rendered in.

base	heaters	stirrer
heat plate	tank	lighting
stir bar

Thoughts

I’m happy to say that I feel much more comfortable with Inkscape and Sketchpad. And that I at least am aware of the free tools that are at my fingertips. I will be fairly honest, I think I’ll stay with using my paper and pencil for sketching. In my experience, I usually don’t like to get too deep into the 2D drawing process since I go straight to CAD.

• It was more controlled and structured than just sketching, so I feel like my final drawing and the layers were actually pretty useful from a design standpoint, since I could flesh out exactly where went what, and what subsystems might look like.
• It also forced me to think a little more about all of these details before committing to CAD.
• Without a stylus and a touchscreen, sketching is actually pretty tedious using a mouse and keyboard.
• I wasn’t a huge fan of how my sketches came out and additionally, it took longer to make sure everything looked somewhat legible.
• Inkscape was also slightly unnecessary I think for my use cases.
• I didn’t like how long it took in comparison to CAD. Especially since it was just an additional step I had to do before going to CAD, and because CAD can also be used to design and then display a model once you’ve finished it. At more angles too!

Sources

• Introduction to Inkscape by Gavin Corley, Inkscape Wiki