cold weather

[Martin Harris - Moderator]

Jeti has a low temperature cut-off which prevents the transmitter initialising below a preset temperature. I think it's -20 C but I can't guarantee my recollection.

I found this out when the Profibox that I was using as a transmitter module before dedicated transmitters were available "failed" one cold day at a little below 0 degrees C - warming it made it work and it continued to function after cooling until restarting (tested in the freezer when I got home!), so I sent it back to the supplier as faulty - in the meantime, I received an unreleased software update from Jeti after enquiring about the problem so forwarded it to the supplier who uploaded it and found it cleared the "problem".

Edited By Martin Harris on 30/11/2017 18:34:07

[Frank Skilbeck]

Posted by John Stainforth on 30/11/2017 18:22:08:

What, BTW, is the typical operating temperature range of modern RC radio gear? I remember in the old days (early '60s) we used to worry about that because receivers could suffer a catastrophic loss of gain at sub-zero air temperatures. I've looked in my Spektrum manuals and can't find that information.

It's well below when my fingers and thumbs stop working

[onetenor]

Beware 2 volts Some plugs can be burned out at 2v ASk me how I know.I used to use an old GPO lead acid cell and burned out a Cox .o49 plug .I replaced the integral plug with a standard screw in plug ... Drifted out the solid plug and tapped it to take the screw in one.. Quite easy to do.

[Don Fry]

Sorry lads, but this argument goes round in circles. To get a moter moving requires good fuel, air, and a heat source.

Fuel is for another post. If there is no air yer dead. Problem disappears. But heat source, for a glo plug, comes from a METERED SUPPLY.

An ammeter tells you you have a over wet plug, ( high amps). Or a flat battery, ( low amps). And you need a proper 2, 3, inch ammeter.

And a variable resistance in the circuit allows for the use of different value plugs. Which either needs a variable resistance unit. A potentiometer does the job, or bits of wire at different lengths. But the bits of wire blokes will use a common plug for their motors, (i.e., I only use an OS FS plug).

Rant over, but you need a meter.

[Jon H]

As an insurance in cold weather I charge my batteries before I fly so they have some heat in them. When I have the model set up and ready to go I fire up the radio and systematically waggle all of the controls for a reasonable period of time. My logic is that the current draw will raise the temperature of the chips even if only slightly. I have no idea if it does any good, but nothing has ever failed so I will keep on it!

[ASH.]

I've had no trouble starting my glow engines in cold weather. The trick is to leave the glow stick on for 15-20 secs before cranking with the starter. i make sure engine is well primed and test the glow stick on a spare plug to make sure it's glowing bright. I run my 12V starter with a 3S Lipo.

Also, the mixture needs to be fattened-up on both the top and bottom end. I had to turn out both needles on my 4st a 1/4 turn to idle well. Cold damp dense air requires more fuel.

[Don Fry]

ASH, are you honestly saying, your glow stick needs 15 seconds to get the plug glowing. And you test the glow stick on a spare plug, because you don't trust the glow stick. Why not place your trust in OHms law, and measure something.

And Jon, when was the last time you charged your car battery because it will be cold in the morning. A sufficient battery does not give a monkeys fig what the temperature is.

Edited By Don Fry on 30/11/2017 20:41:06

[ASH.]

No Donald, it doesn't need 15 seconds but that's what I give it. It guarantees an instant start every time. Let's not forget glow fuel is cold and a nice wet engine leaves the plug damp. Using a 1.2V glow stick does no harm to a good plug at all. If using variable amps and such then much more chance of frying something!

[ASH.]

I've never owned a power panel, I use to carry a 12V lead acid for the starter now I use a light 3 cell 2200mah Lipo - plenty of umph always!

I hope to do away with glow sticks as well. Got myself a 1.2V glow starter which can be used with a Lipo - need to solder some plugs first.

**LINK**

PS. I'm not a fan of Lipos but - '..needs must'.

[onetenor]

Something that may help is to wrap batteries in bubble wrap before leaving the house .After all you put your own coat on don't you

[Brian Hammond]

I pinched my wife,s cool bag and take my lipos to the field in that,it keeps them at room temperature.