Spreading the charms of Japan to the world from Fukui




I looked for a carrying case for large Li-Po batteries


Production notes


I was looking for a suitable case for storing and transporting large Li-Po batteries for drones for spraying agricultural chemicals. Considering the risk of ignition of the batteries, plastic is not completely safe. On the other hand, aluminum is not strong enough. So finally, I found an iron ammunition case that originally had made for a military purpose.


When I put eight batteries, each battery is about 1.6kg and the case itself is 3.2kg, so the total weighs 16kg. But there is no distortion around the handle unlike an aluminum case I tried before, so it is quite sturdy. I need a bit strength to open and close it, but it can also be expected to be airtight to block water and air. Since there was a convex part at the bottom, I put a cushioning material to make it even.


Armylike appearance


Eight batteries just fit into the case.


Made a carrying case for a mini drone


Production notes


I made a carrying case for storage and carrying of the mini drone bodies, parts and a transmitter that I usually use for practice. Actually I only put the cushioning material called block cushion in the commercially available aluminum case for tools, but even so, the size of the cushion was just right and easy to process, and I was satisfied with the finished result.


The block cushion has 15 mm square cuts on the entire surface of a large sponge. In other words, it is a block of the 15x15x60 mm sponge pillars. The pillars are connected to each other in some points, and it is easy to make a hole without using a special tool because you can cut the connected points by hand or a ruler. Furthermore, I cut the sponge taken out of the holes into a suitable thickness with a cutter. Then I returned it into the original holes, and made the bottom parts according to the height of the things to be put there. 


But this is not good enough yet, because the upper half is left empty, and the contents will fall apart when you lift it, so I packed some cushioning material on the back of the lid as well. I removed the panel for tools and writing instruments originally attached there.


Space for the replacement parts has two stories.


Block cushion placed in the aluminum case (before being processed)

Tello, first automatic flight


Production notes

After struggling for two days, I finally succeeded in flying a Tello toy drone automatically.


I often use the toy drone priced at around 5,000 yen. It's good for practice because it's safe to fly indoors, and it's less stable than the bigger one (like a Phantom one) so I can improve its flight stability by using it.
Recently, I bought a Ryze Tech Tello toy drone, which is expensive for a toy drone. Because I found out that the Tello could be flown automatically from a book.


At first, I installed the latest version of Scratch without reading the book carefully. And I became confused because the action of the application was different from the description in the book. I solved this problem by installing the old version "Scratch 2.0 Offline Editor" again.


The book is written for Windows, which made me even more confused because I usually use Mac. One of the different parts is to run a node.js but it's explained in Sky DRONE's video "Programming RYZE Tello with Scratch (Mac edition)" and, which was helpful for me.


Unlike manual operation, there are restrictions such as not being able to do more than two operations at the same time, but it seems to be possible to do some interesting demos.

The mysterious extension "HEIC"


Production notes

iCloud Photos on Windows


I sometimes use pictures and movies taken with my iPhone on this site where I use Windows to create pages. And recently, I noticed that some files with an unfamiliar extension "HEIC" appeared in the iCloud Photos. The file name of the newest QuickTime movie also has the word "- HEIC" at the end of it while keeping the extension MOV.


Because the corresponding file name to JPEG is attached, I thought it might be any additional information. But in fact, it was a new image compression format to replace JPEG. You can make a file size much smaller than JPEG with it.
As expected, Apple changes things dramatically as they adopted USB interface on iMac twenty years ago. This format will become the standard soon as well as USB. Is it a transitional measure that HEIC is paired with JPEG now?


Nonetheless, if I cannot open it on Windows from now, I will be in trouble, so I changed the format to 'compatibility priority' for iPhone's camera settings.


No change on Mac

Drone simulator


Production notes


I decided to use a simulator for practice drone manipulating.
I also use some mini-size quad copters so-called "Toy Drone", but frequent replacing batteries is bothersome.


I got a racing drone simulator software ($ 4.99 / about 555 yen), "FPV Freerider" . Transmitter is Futaba's T10J. I connected this to my MacBook with a simulator cable I bought from Amazon.


But how hard it is to control the aircraft with the simulator!
It is quite different from the drones I usually use for aerial photography and I cannot even hover normally. It took 2 days to get through the first gate.


I have gotten used to it little by little, but I don't know when it will be possible to turn the whole course.


I actually felt that what is called a drone is actually flying with a very delicate control.