A Word of Caution with using Hand Warmers

[Chrislaf]

Yesterday, my NEO had a yaw error and flew away and crashed. Aside from a broken propeller and a few minor scuffs my NEO was fine. The yaw error was due to me powering on the NEO near my rechargeable hand warmers that were in my coat pocket. The hand warmers have magnets in them to hold the two of them together to create warmers on both sides. It was cold out and I was hand launching with my RC-N3 controller in my other hand. In my haste, I failed to check the drone orientation on the map (which I always do) and the NEO immediately flew away at high speed and crashed.

I was surprised that the magnets in the warmers were strong enough to cause magnetic interference since they don't seem very strong. The other day I did an experiment with disposable hand warmers which use iron powder to create heat - I attached a warmer to the bottom of the NEO battery to see if it would be able to heat the battery to prevent the 'Preparing to Takeoff: IMU warming up' errors that occur when the temperature is lower than -10ºC and it caused the compass to go all wonky so they can affect the NEO as well.

The reason I mention all this is because if you fly your NEO in cold weather and use hand warmers be careful!!! If you are using an external controller like the RC2 or RC-N3 make sure you check the drone orientation on the map or radar. If you are using a phone or just the drone control panel where you can't check drone orientation, then maybe temporarily remove your hand warmers from your mittens/glove or pockets or launch from a landing pad or other surface.

I know I am going to be extremely careful especially when using just my phone or the drone control panel.

Chris

 

[NeoNeo]

Tubes Canada! Few Christmas ago for a gift purchased the Muff Vintage version. Person was impressed with the quality of build and function. Was considering eventually purchasing the basic Tube to keep the hands warm or to warm them up between flights, option for keeping the batteries warm. They have a pocket to hold the chemical or battery powered hand heaters if needed. Multi purpose use product vs. one of those TX cold weather boxes.

 

[Chrislaf]

Tubes Canada! Few Christmas ago for a gift purchased the Muff Vintage version. Person was impressed with the quality of build and function. Was considering eventually purchasing the basic Tube to keep the hands warm or to warm them up between flights, option for keeping the batteries warm. They have a pocket to hold the chemical or battery powered hand heaters if needed. Multi purpose use product vs. one of those TX cold weather boxes.

Those look interesting. I have never heard of them before. Might look into them more.

Chris

 

[RcHawks]

Thank you for the tip Chris, who would have thought that it be a problem because as you said the magnets seemed weak. Back when I had a ID card for work I found out by the hard way by putting it under my Iphone cover so not to misplace it and it affected my reception as many of us found out. I've been paranoid about anything containing a magnet such as my wallet near anything electronic ever since.

 

[Chrislaf]

Yeah, I was surprised. Going to be careful with them now.

Chris

 

[NeoNeo]

Riding up the chairlift this AM it was a bit cool at -12C. Chill induced thoughts regarding Tx Warming Gloves/Boxes.

Just did a quick search for a few R/C specific Tx Gloves. Not much in choices left in the R/C world. Decade ago considered the Hyperion and AceWingCarrier. Hyperion came with 2-3s lipo powered heating pads for less than $35. No longer in stock anywheres. AceWing are still available (made in AZ, USA) and still very expensive. One design factor looking for was not having the clear plastic window resting on the of the hands. Thinking that would be annoying. Hyperion and Ace supposedly designed to keep the window off the hands. In desperation looked a eBay. Bunch of seller selling the same model. Image looks like the clear window is semi rigid. Double layered like ski/snowboard goggles to reduce fogging. Might be the option to try. Marketed for DJI controllers. On the fence. Could be a waste of another ~$25.

Anyone try this specific model?

 

[RcHawks]

I made one about 35 years ago for flying rc gliders and later added a handmade sheepskin backing for winter conditions, very similar in concept. I also had a plastic window to see thru for the transmitter. I designed it to hold a video recorder as well so I could film while flying on the slopes. It's too big for my purpose now, but I did like how well it worked at the time.

 

[Chrislaf]

I have a transmitter mitt similar to the one posted above that I used for my old P3S. It’s a bit too big for the integrated controllers or my RC-N3 controller, but it did keep the wind off my hands. They would still get cold on really cold days.

Here’s the one I have.



Chris

 

[NeoNeo]

wtotoy seems to be one of the common tx gloves. Checked to see if HobbyKing still sold their adjustable heating pads. Either wrong search terms or no longer stocked. Passed on the HK. The Hyperion with heating pads was not much more money. Plus at that time I was a bit of a Hyperion battery fanboy for 1s indoor tiny whoops. Did not figure that these "gloves" would have such a small market rendering them more or less extinct.

Spring on the ice quad flying are shorter flights due to limited battery capacity and cold v. electric launch sailplane(ELS). Usually get by with just warming the hands for a moment or two between batteries. ELS, bit numbing experience. Always wished I had a functional TX glove. Get home. Cheapo me kicks in. Limited use. Why buy. Not the brightest bulb in the room.

Probably should buy the one in the above attached image. It looks to be more like a box type Tx glove. But....could be just the pictured ad vs. reality.

 

[bbteach]

Most chemical hand warmers are filled with ferrous (iron) oxide. I am not surprised they cause compass issues.

 

[Chrislaf]

Most chemical hand warmers are filled with ferrous (iron) oxide. I am not surprised they cause compass issues.

I have used them for years without problems. As long as they are not close to the drone (ie. hand launching with one in your mit) you should be ok.

Chris

 

[NeoNeo]

I have used them for years without problems. As long as they are not close to the drone (ie. hand launching with one in your mit) you should be ok.

Chris

Good to know. Plan is to stick a couple inside the Tx glove box if needed. They seem to release a bit of moisture along with the heat. Hopefully that will not be an issue if placed inside the glove box.

 

[Droning on and on...]

I have used them for years without problems. As long as they are not close to the drone (ie. hand launching with one in your mit) you should be ok.

Chris

Makes total sense. Passive iron filings are not emitting a magnetic field. They distort it. So very very close to them the weak earth magnetic field will be slightly altered (like less than 2-3cm).

An actual magnet, OTOH, like in those electronic warmers, is an entirely different situation. The earth's magnetic field in N. America is about 25,000 nT. A typical refrigerator magnet is about 0.01T, or about 400 times as strong. The iron filings will cause the results of the compass to be a little off.

The magnets in the hand warmer will be detected by the flux-gate compass as an external magnet, and throw a warning, as it can detect the massive excess strength.