How to dispose / utilize LiPo batteries

LiPo batteries that run RC hobby are potentially dangerous devices. When not handled properly they can ignite or even explode. And they do not live forever. Even the best battery, no matter how taken care off, loses capacity, swells and has to be disposed. When we combine both facts we face a problem: how to dispose old LiPo batteries if they can catch fire? It’s extremely hard to find a place that accepts them for utilization. Throwing out with garbage is not a good idea. Disposing with popular alkaline batteries might sound as a good idea, but it is not either. So, how to utilize old LiPos? This is quite easy…

  1. Build a LiPo discharge device using 24V halogen light bulb. No high-tech here, just a way to connect light bulb to a battery. 12W halogen is generally a good option for both 3S and 4S LiPos
  2. Put a battery inside ceramic pot with some sand (not flammable if thing go very very wrong for any reason), connect “discharge device” and let it do its job. Light bulb limits discharge current, so LiPo should discharge nicely without extra swelling or overheating Magical LiPo tree Continue reading “How to dispose / utilize LiPo batteries” »

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How to print PLA on glass?

When I got my first 3D Printer (Malyan M150) and got into 3D printing I was surprised how consumer not-ready technology this is. Sticking, not sticking, overextrusion, underextrusion, Kepton, blue painters tape, clogged extruder… Over the time, at least, I was able to get the whole 3D Printing process somehow repeatable. I think one of the most important changes I’ve made in my 3D Printing experience is to ditch Kepton and blue painters tape in favor of printing PLA on heated glass. Process got simpler, faster and with better results. Also, not counting initial investment, cheaper.

Malyan M150 printing PLA on glass Continue reading “How to print PLA on glass?” »

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How to reverse motor direction

You finished your build, you connect LiPo, power up flight controller, apply throttle (no propellers of course) and you see that one or motors are spinning in wrong direction. How to fix that? You can not do it, for example in Cleanflight Configurator. ESC communication protocol does not allow to change BLC motor direction.

There are 4 ways of dealing with this problem:

  1. Hardware way that works all the time: swap any two motor wires. Does not matter which, just take any two and swap them between motor and ESC: A with B, B with C or A with C. If you have bullet connectors, it's simple. If you soldered wires to ESC pads, you would have to resolder them. How to change motor direction
  2. If you have BLHeli ESC software, BLHeliSuite allows to change motor direction without swapping any wires. Connect to ESC with BLHeliSuite, and change Motor Direction option. blheli motor direction This works only with BLHeli enabled ESC, and only on Windows.
  3. Most of ESC allows to change options like motor direction via transmitter. Exact procedure differs from manufacturer to manufacturer, but usually it looks like below. For exact procedure and possible options refer to ESC user manual!
    1. Connect ESC to radio receiver throttle channel or use flight controller configurator software Live mode. Remember to remove propellers!
    2. Throttle UP
    3. Power ESC, it will start to beep signaling number of cells
    4. Keep throttle up until you hear a sequence that confirms programming mode has been entered
    5. Wait to hear beeping sequence indicating Motor Direction option
    6. Throttle DOWN
    7. Wait until you hear beeping sequence indicating desired rotation direction (normal or reversed)
    8. Throttle UP
    9. Setting will be changed and after next power cycle rotation direction will be changed
  4. Sometimes special programming cards for ESC can be acquired. They somehow automate procedure from point 3 but work on the same principle. For exact programming procedure refer to programming card user manual.

EMAX esc programming card

EMAX programming card photo [1]

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How to cut Depron

Depron is an amazing material. Light, cheap, waterproof, easy to process and quite durable. Almost everything in RC world can be made from Depron. All one needs is imagination, glue and proper knife. Like I mentioned few times before, I’m cheap, so at the beginning of my adventure with Depron, I was choosing cheap modeling knives. Usually no-name. They had one very serious flaw: knife’s blade had to be replaced every few cuts. And even so, cut was far from perfect.

olfa knives SK-9 and SKB-2

Luckily, I’ve found a perfect, more expensive but cheaper on a long run, solution: Olfa Knives. Especially Olfa SK-9 Knife with SKB-2 Blades. They are sharp, strong and lasts for a long time. When needed, SKB-2 blade can be used without a knife. SK-9 has one disadvantage: there is no lock, so keeping blade extended all the time requires thumb to be used. And that make it hard to switch knife between hands.

But the bottom line is: I love Olfa knives. Not only when working with Depron. They are very useful with dealing with cables, unpacking and so on…

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The best way to mount LiPo on a drone: 3M Dual Lock

LiPo battery, as the heaviest single element of any racer quadcopter, is mostly the first one to fell off during crash. Or displace in high-g maneuvers. Or simple fell off in flight. Like on this picture below I’ve found on Reddit. Grrrr… for sure this is something I would like not to see personally again. And I’ve seen it on my first build based on X525 frame.

battery fell off

So, solid and strong battery mount is a must. Battery strap for sure. Even few in case of heavier ones. But battery strap is not enough. LiPo can always slip out. To prohibit that, I’ve been using velcro strips and it worked fine. But velcro has a few drawbacks: it is not very strong connection, allows some movement, and looses strength after some time. Few weeks ago I’ve discovered something that is way way better than regular velcro: 3M SJ3550 Dual Lock Reclosable Fastener. Continue reading “The best way to mount LiPo on a drone: 3M Dual Lock” »

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Make your drone stands out with insulating tape

Everybody knows that red is the fastest color. Ferrari has proven that years ago. With red Turnigy Graphene LiPos I’ve bought recently, I’ve decided to make my ZMR250 quadcopter stands out a little. In a cheap and dirty way: if I have red battery on top of ZMR250 and I can buy a propellers in almost any basic color, why not to go one step further?

Idea of making the whole drone red was in my head for a second, but it died a sudden death. Paint would not do. Too fragile and too effortful. Instead I’ve visited a hardware store and purchased color insulating tape. They come in different prices, sizes, qualities and of course colors. Classical black, green, blue, yellow, red, etc.

At home I’ve applied red tape around arms and ESCs. That also allowed to get rid of zip ties that I used to hold ESCs in place before. They were not good. Insulating tape is not only stronger by also protects ESCs better from dirt and water.

Red is the fastest color on 250 quad

Effect? Quite nice, I like it very much. Red props (DAL T5040 that I will review soon), red arms, black carbon and Turnigy Graphene are looking nice together. And this ZMR250 for sure no longer looks like regular ZMR250. All for just a few cents worth of insulating tape!

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