Design projects | Re-Engineering Labs

The Kayak Tech Survey Outcome

Posted on June 30, 2018 by Julian Chua

Almost 6 months ago, I wrote a short post about (what I thought was) a lack of technologies for monitoring training in flatwater or sprint kayaking. To make sure that it wasn’t just me thinking that way, I created a survey and sent it to a couple of kayaking friends who graciously helped spread the word. I also posted a link to the survey on social media (i.e. Twitter) which I think wasn’t quite as effective. Overall, I didn’t get a big response but it still gave me a peek into things. So let’s dive into it and see what it’s telling us.

Key Stats

So here are some key stats as captured by Typeform:

There were a total of 120 visits, of which 101 were unique and out of the 101, there were 37 responses. This means a 36.6% response rate. Among the 37 responses, 14 were done on Laptops, 23 on Smartphones, and none on Tablets.

Screenshot of Typeform Key stats

Some Details

Then onto the 6 questions:

Training frequency per week – 30 out of the 37 responses said they train at least 2 times a week or more.
Yes/No to use of technology during training – 30 out of 37 use some form of technology to track their training
Regarding the type of technologies they use – 29 use a GPS watch, 19 use a heart rate strap, 8 use a smartphone app, 3 use Motionize, 3 use Vaaka Cadence, 2 use a SmartWatch, and 1 uses a GPS + IMU unit. (note that some people use more than 1 piece of technology)
The number who do not use technology – 5 responded that they do not use any technology and the most popular reason is that they have not tried them
What they liked about their current technologies – Being able to track Heart Rate (n=18) is the top thing that people liked. This is followed by Pace (14), Speed (11), Distance (8) and Stroke Rate (4) (or cadence).
Regarding improvements they would like to see, everyone had slightly different preferences. But in essence, 9 said they would like a kayaking specific device or app, 6 wanted stroke rate available in their existing devices, 6 wants some form of power monitoring (that is affordable), 4 would like to see stroke/technique analysis, 3 wants greater accuracy and reliability in their tracking, and 2 would like a better visual of their data.

[If you would like to see it on Typeform, here’s an overview of responses to the first 4 questions: link]

Even though I only had 37 responses, there was a good mix of opinions; and I take away 3 key things out of the above data:

The GPS watch is the most commonly used tech. It makes sense because it is a multi-functional device – it can be used for running, riding, swimming or just for everyday use as a watch.
More than half (19) of the people use a heart rate strap and it seems most of them value the heart rate data.
Although there are technologies out there that can be used/adapted, 23 out of the 30 still wants some form of improvement to their devices. The most common feedback is there isn’t a kayak specific device or app.

I reckon most people would have a similar setup as the athlete in his Instagram image below – wearing a heart rate strap and with a GPS watch mounted onto the kayak in front of the cockpit.

Tom Liebscher’s Instagram photo (link to original photo)

Additional Info

Also from the few conversations I had with some of the kind people who did the survey, most (if not all) GPS watches don’t track stroke rate, and the accuracy of the speed measurement during short distances/sprints/intervals are not very good.

What I didn’t get a lot of information or feedback about are those kayak specific technologies that are actually in the market like Vaaka Cadence, Motionize and Kayak Power Meter. It seems like not many people have used them. This could be because of the price or a lack of opportunity to try it. I will be digging a little bit deeper into that.

What next

The main outcome I took out of this little exercise is that my initial hypothesis has its merits, and it’s worth pursuing this further. The few options that I am exploring further going forward are (in that order):

Smartphone app (likely iOS)
A kayak specific device like a kayak computer
Garmin Connect app

As this is really just a side project here at ReEngineering Labs, the progress might not be as quick. Nevertheless, it will be moving forward and I will be posting updates every 3 months.

If you are reading this for the first time, please do check out the earlier post here, and have a go at the survey here. If you would like to give your input on kayak technologies or even be part of this project, drop me a message here. To get notifications about this project, simply subscribe on the right.

With that, thanks for reading!

Designing an iPad Cooling Case

Posted on November 10, 2013 by Julian Chua

A while back, I was referred to someone who had an issue with overheating iPads (the 3rd gen one). Due to the nature of his work (coaching/sports science), he often uses the iPad under the sun, which contributes a fair amount of heat to the iPad, and it was overheating to the extent that it would shut down. The shutting down was meant to be a safety feature to prevent it from blowing up, but this became a huge inconvenience for him. So the challenge for me was to come up with a solution to cool down the iPad so that he can continue using it under the sun.

RESEARCH

First I did a bit of research on the internet, and found that the new iPad (3rd gen) did have an issue with overheating. An article from Reuters even found that the iPad racked up temperatures of up to 47 deg Celsius after 45 minutes of running an intense action game. It didn’t bother most people (from what I read on the forums) because they will just stop using the iPad when it got too warm and let it cool down, or use it on the table instead of holding it with their hands. But for someone who needs to use the iPad as a sports training tool under the sun, it was a problem.

DESIGN RESEARCH

Next I explored the possible options for cooling the iPad:

Cooling with water – People who overclock their PCs are usually the ones who would try using a water cooling system. You could build one on your own, or buy a system off the shelf. It will work for a PC, but an iPad? I am not too sure. I think one thing for sure is it will make the iPad way too bulky.
Using an ice pack – Anything that is zero degrees should cool things down. But, the thing is, it will also cause condensation. There will be water droplets everywhere, your hands gets slippery and oops, you drop the iPad on the ground. Not a good idea.
Heat sink – Heat sinks are only effective if there is complete contact between the hot surface and the heat sink; and typically that is achieved by applying heat sink compound or thermal paste between the surfaces. Also sticking a couple of heat sinks at the back of the iPad might make it less ergonomic to carry.
Cooling fans – Now this might work. All we need is somewhere to mount the fans, allow the air to move around the back of the iPad and carry the heat off the surface.

FEASIBILITY TEST

Out of the 4 options, I picked the cooling fans since it seemed the most feasible solution. My initial plan was to build a 3D model and run a CFD simulation to test out the concept. But when I started to draft something on SolidWorks, I ended up designing an iPad case which could house two 10mm fans and with channels for directing air across the back of an iPad. Then since I had access to 3D printing, I decided to just build the prototype, get two 10mm fans and ran an actual test with the iPad.

1st prototype with fans

On one of the few sunny days in autumn, I borrowed a 3rd gen iPad and subjected it to some ‘heating’. I turned on the iPad, stuck a thermocouple on it’s back and left it under the sun. It was about 30 deg C that day. Once the thermocouple reading reached 45 deg C, I inserted the iPad into the prototype case and turned on the fans, while leaving it under direct sunlight. The good news was that the temperature dropped by 5 deg only after a minute or two with the fans on. But rate of cooling slowed down after that and it dropped to 34 deg C after 20 minutes. 34 deg C is still quite warm but since this is still under direct sunlight, and it was a 30 deg C day, I would say it was quite effective.

DESIGN IMPROVEMENTS

In my opinion, the concept worked. The design just needs a bit of tweaking. Firstly, I didn’t get the dimensions of the iPad right so the case didn’t really fit that well. Secondly, I picked the wrong fans – they were a little too big and they needed a 12V supply. Thirdly, the fans had to be switched on manually – it would be better if there was a temperature controlled switch.

So I got all those sorted out:

Improved the case design. Even added a slot to mount a wide angle lens for the rear camera.
Found smaller fans that only required 5V power supply.
Also got some help with building a temperature sensor circuit that will switch on the fans when it gets too hot (it’s adjustable via a variable resistor).

NEXT PHASE?

Before I went ahead to build a second prototype, I decided to find out how much it would actually cost to 3D print it (The first prototype I got was given to me in kind). To my surprise, it would cost over $600. It would actually be a hundred dollars cheaper to have the case prototyped using CNC machining. On the other hand, all those electronic components plus the fans would only cost less than $20.

Well, if I was making a few thousand of those cases, I could just design moulds and get those parts extruded which would then bring down the cost of each iPad case. But how many people will actually need a cooling case for their iPad??

Also when I was working of this project (back in April), there was already the 4th gen iPad in the market, which was kind of an improvement. There were still complains of the iPad 4 being too warm, but I was thinking, it wouldn’t be long before Apple came up with a newer model that will totally solve the heat issue. Fast forward to today, out comes the iPad Air with a brand new processor! Apple has also stopped manufacturing the 3rd and 4th generation iPads. That’s probably because they realised they were inferior designs!

IN THE END

Although I didn’t get to mass produce these iPad cooling cases, it was overall a good experience. I realised that I would have to work faster if I wanted to make accessories for tablets or smart phones because a newer and better version is always coming out. Also the cost of commercial 3D printing services is way too high. If I wanted to get 3 prototype cases built, I will be better off buying myself a 3D printer. The cost of thermoplastics for printing doesn’t seem too expensive. Might be cheaper than traditional ink cartridges!

Anyway, thanks for reading, and if you think this iPad cooling case is a good idea and you want to get one, leave me a message!