Specifications and Constraints: Cargo Kite

Specs: Large/Heavy-Lift, Rigid, Stable in Flight, Minimalist but Interesting, Unthreatening but Visible

Constraints: TIME, man all those materials were expensive, Shop Availability, Sewing Ability, Headspace?

One of the biggest goals of this design is to be large! This comes from both its ultimate purpose – being a kite that lifts things – and from my personal interests. The common perception of a kite is a small thing, probably diamond-shaped. Thus, it may be a bit of a surprise to hear the word ‘kite’ and instead be faced with something that comes up to your chest. In short; I find it cool! Further, the kite being large naturally lends itself to a heavier payload – I’m not sure what I intend to lift, but I’m confident that this massive kite will give me enough lift to work with.

Another goal is for the kite to be rigid. As I mentioned in a previous post, I designed a sled kite in high school. It was perpetually plagued with issues. It would collapse and fall if flown poorly (it was impossible to fly well, due to other design issues, but that’s neither here nor there). As such, I wanted a rigid kite this go around; the stiff truss design of my box kite should take care of that. While I haven’t done a thorough analysis on the mechanics on this kite, I’m confident that the 8 large fiberglass spars will be enough to prevent the kite bending.

Another result of my high school kite’s poor performance is my want for this kite to be very stable in flight. Acrobatic or fighting kites are very interesting, don’t get me wrong, but I don’t want to fight the kite to make it stay still. Plus, if I’m going to be lifting payloads with this kite, it would probably be best for whatever it ends up carrying to fly calmly.

In regards to the design, I wanted this kite to be ‘minimalist, but interesting’. I could have very easily designed this kite with no aesthetic considerations in mind and made a final product that visually relied on its bare-bone required structures alone. However, I’d prefer if this kite didn’t look like a flying brick, and was genuinely pleasing to the eye, if still simplistic. This is why I put effort into pointedly choosing dimensions, colors, and shapes within my design.

Some of these design choices also factor into my desire for a look that is highly visible but non-threatening. Part of the reason I chose to round the edges of the sails is to imply that this kite is trustworthy and safe (per Contour Bias). However, this is being tempered by part of the sails being fluorescent orange – it’ll stand out against the sky, allow me to easily see the kite’s orientation, and give the kite a very test dummy / aerospace look – hopefully, it won’t make the kite too striking.

Easily the largest constraint is time. Over the next month, I have a major design project and exam in thermodynamics, a large literature review in mechanics of snow, and so, so much to do for senior design. (I tried to make this semester easy on me, and look how far that got me!) Luckily, materials are starting to arrive, so I’m fairly confident I’ll be ready to present on time.

Cost is a constraint that, while passed now, still hurt in the moment. I ended up shrinking my kite by a factor of 1.2 in order to get better costs on fiberglass tube spars, but even after all that, I’m $150 in and not quite done. It’s to be expected, for a large custom kite.

I worry that manufacture will be limited by shop access. I plan on using the ITLL, which is a lot quieter than the IdeaForge in my experience, but I may still run into times where I’m significantly delayed by the volume of students in the shop. I’ll be trying to go at odd hours that I’m free in the hopes of missing the ‘rush’, if there is one.

I have my own sewing machine that I would prefer to use for its availability, but it’s a small thing that may not be up to the task of stitching these relatively large nylon sheets together. In that case, I’ll have to use the machines in the IdeaForge, or perhaps the BTU Lab. I know how to sew; I’m just concerned that I’ll have to schedule a workshop to gain access and they may not be available.

Lastly, and more somberly, I might be held back by my headspace. To avoid going into too much detail, I’ve had a rough two years, and I’ve been burning at both ends for too long now.