Helicopters and HiFi - Where is Stan when I need him?

[Oldpinkman]

http://i1315.photobucket.com/albums/t582/oldpinkman/meandheli_zpsb74fea1b.jpg (http://s1315.photobucket.com/user/oldpinkman/media/meandheli_zpsb74fea1b.jpg.html)

Poor Mrs S - A Helicopter widow AND a HiFi widow. Her fault for buying me a micro indoor for Christmas, and introducing me to her best mate from Trinity - who flies Heli's!:)

http://i1315.photobucket.com/albums/t582/oldpinkman/helionbench_zps4181f0f3.jpg (http://s1315.photobucket.com/user/oldpinkman/media/helionbench_zps4181f0f3.jpg.html)

This is a 600 size TRex electric Heli - I have just stepped up to this from 450's (I have a Blade 450 3D as well)

http://i1315.photobucket.com/albums/t582/oldpinkman/heliclose_zpsa5072ce2.jpg (http://s1315.photobucket.com/user/oldpinkman/media/heliclose_zpsa5072ce2.jpg.html)

Fair bit of electronics on this bird. And unlike HiFi there are serious safety considerations to flying these - they would cause serious injury if they hit you, or property, and can escape my paddock in under 2 seconds. These birds fly serious 3D!


http://i1315.photobucket.com/albums/t582/oldpinkman/battery_zpse59eb5aa.jpg (http://s1315.photobucket.com/user/oldpinkman/media/battery_zpse59eb5aa.jpg.html)

There are of course soldered electronic joints in the ESC the receiver, gyro, and voltage regulator - all vital to safety. Not unlike the vital to safety circuits in the spacecraft which launched Stan's Avatar into space. Or dozens of safety essential soldered joints in any airliner. But of course, not high current applications like 1 amp from a 12v battery (for an alarm backup ? -even 1 amp I doubt). But I quote Stan

"As for the debate of crimped versus soldered connection: You are plain wrong. In fact dangerously so... A crimped connector will still continue to work long after a soldered connection passing the same amount of current and voltage has failed. When solder heats up and cools down it will start getting brittle and eventually separate into two sections... When you are talking batteries, you are talking about very high currents. A sealed lead acid battery for an alarm is likely to be at least 1AH. At 12V that would be equivalent to 12Watts. A 12Watts soldering iron would melt a soldered connection given enough time.
This is one of the reason why you'll find crimped connections being used in high current appliances "

Take a close look at that battery Stan. I realise your field of expertise is plug sockets and DAC's, and you may be unfamiliar with LiPo's in model helicopters. My understanding is 40C-50C means it is capable of delivering 40 amps continuous and 50 amps peak. Not with me hovering it you understand - but telemetry on the transmitters and receivers we use confirm the serious 3d boys draw those currents. The reference to 5000maH is the recommended ( in the case of this particular battery maximum) charge rate. Its a 6 cell Lipo. I make that 22v for cash (I am only an accountant though). Now my Dad (English language perfected in Crayford in the late 40's) knows 2 and only 2 electronic formulas. In his day they didn't use I for current. So - tell 'em Dad - C=V/R and W=CV. Using the second of those formula I make the power produced by the battery connector 22x50 = 1100w. Some people call that 1.1KW - killer watt sounds so much more dangerous! Or one bar on an electric fire. Or 1.5 times the power of our low wattage caravan kettle

And you know what - although the radio circuit battery uses crimps, that big yellow connector is soldered. Not just because I am a tit. But because the instructions insist on it, there is no alternative means of fitting it, and it is universal to all electric model flight worldwide.

But we could start by letting the BMFA know Stan. I would, but they'd think I was a tit, and I am only an accountant and not an engineer.

Was your comment on my thread deliberately misleading (it wasn't technically wrong) just to try to make me look like a fool, or did you not know what you were talking about? 12 watts! better leave my Hifi on all the time so the joints don't unsolder. And avoid flying in aeroplanes :)

In my experience whining in response to skepticism is usually the mark of the charlatan. The engineers I know and respect respond to skepticism with scientific theory or experimental evidence. That I believe was the response of both Barnes Wallis and James Dyson.

[NRG]

The 5000mah is the capacity of the battery not its rated charge rate. Those particular Turnigy Lipos are 35C rated not 40 to 50, so peak discharge is (35 x5000) / 1000 = 175amps. A heck of a lot! or nearly 3.9KW at 22.2volts :stalks:

[Oldpinkman]

The 5000mah is the capacity of the battery not its rated charge rate. Those particular Turnigy Lipos are 35C rated not 40 to 50, so peak discharge is (35 x5000) / 1000 = 175amps. A heck of a lot! or nearly 3.9KW at 22.2volts :stalks:

The pride that comes before a fall :(. I've just bragged elsewhere about checking my facts before publishing. I could blame holiday packing pressure, but I guess better to man up and 'fess I screwed up. (I had realised the capacity point, but forgotten the other. And whilst some batteries allow charging at 2C - that one is restricted to one C. And on the label it says 40C to 50C I promise you. Mind you - it's chinese - nuff said. :doh:

And even 35C 3.9 killer watts rather reinforces the point I was trying to make.

Definitely time to pack my bucket and spade now ahead of some serious refreshment :cool:

[Gordon Steadman]

Old Ghengis here doesn't care a fig for all that stuff that's printed on spec sheets.

I'm a simple man (Ronnie would say 'very') so I look for just two things. Does it work and how does it sound.

So I find myself between two stools (either painful or smelly I suppose) I like to know how stuff works just because I am a curious fellow but as I, like Oldpinkman apparently, don't have the technical knowledge to figure out electronic stuff, I just have to worry about the sound in this case. I have never been able to tell the difference (or care for that matter) between mains cables, can hear a small (very small) difference between interconnects and speaker leads, I can hear considerable differences between amplifiers and CD players and huge differences between cartridges and TTs.

I can quite understand the obsessives for whom this is all important but as soon as the music overcomes any possible deficiences in the system, thats where I stop and enjoy.

We have discussed this before -and I've been in trouble with some for knocking the box swapping - and it will go on forever.

However, I see no point in the non technical arguing with the trained and experienced about things that to me don't matter. I am just the user in the arrangement and i say thanks to those who provide the basis for my musical enjoyment.

Hope you have a nice, relaxing holiday.

[Oldpinkman]

As ever Gordon, I sort of agree :) I am very hopeful that by this time next year I will have stopped box swapping for a decent interval too (maybe play with those bloody 53's, but otherwise...)
Certainly its about the music. Sometimes it helps to know why. Let me give you an example

That GORGEOUS cartridge you have got sounds that way for lots of reasons - not just the way it looks from the outside. Among them are the suspension, the boron cantilever, and the tiny stylus - and its very low effective mass. I draw your attention to my needle from Arizona thread, where I have my own beauty sharing those qualities. Standing ready to be corrected again, I was led to believe that since Technics (a banned word) stopped making cartridges, nobody is making boron cantilevers by vapour deposition (I have resisted the american spell-checker this time !)

So aftermarket stylus replacements, which look the same, are absolutely nothing of the sort. Most of the bits that matter are on that assembly. If you love it, and want to keep it, and wear the stylus out, you are going to need to find a VERY skilled specialist to ATTEMPT to fit a new diamond to it. Pointless having them fit a new cantilever with it. And they are delicate and fiddly.

Now I'm sure, being the nice guy you are, you just believed me when I said "Don't touch aftermarket stylus assemblies". But I might have been a fibber, or delusional, or may yet have got my facts wrong. So sometimes its good to know why.

You would hear that for yourself. But only after wasting your money to find out. 'swhy I try to understand what's going on - without trying to be an expert :)

I have a strong feeling Paul and Nicki won't be joining us, so we may yet inflict ourselves on you towards the end of August. Get a bottle chilling! :cool:

[Oldpinkman]

Oh - and this thread can now revert to awed admiration for my piloting skills :D

[Gordon Steadman]

Oh - and this thread can now revert to awed admiration for my piloting skills :D

You need to be talking to Alan, he's the pilot. Slightly bigger things than your rotary blades on them though.

[Oldpinkman]

You need to be talking to Alan, he's the pilot. Slightly bigger things than your rotary blades on them though.

Cool. I promised myself I would get my PPL by 30. Then 40. Then 50... It's harder for me, and restricted because of being monocular, but if things work out right I'd like to do it. I have had 3 proper lessons, and taken the controls a few times with a friend (flown into Le Touquet out of Headcorn in a Robin DR400). But the toys are keeping me happy for the minute. Mind these Heli's are not easy. They are born with a death wish. Take your eyes off them for a second and they crash. Not like the fixed wings where you can leave em up there while you pop off for a cuppa :)

[AlexM]

I fly a TT Mini Titan 450, with Futaba radio and blingy metal bits.

Had it a couple of years, and it's still going strong despite quite a few unplanned heli/ground commings together. Just throw on some new bits (nice and cheap) and off you go again. I did look at electric 600s, but the price of spares put me off.

My battery connections are all soldered too, and none have melted so far ;)

Have fun!.

Alex

[Oldpinkman]

The 600 is a lot easier to fly - I can see the bloody thing for a start, but I have only done some fairly cowardly hovering with it so far because I have been given a written warning by SHMBO about repair bills. I managed to spend more than the cost of the first 450 in repair bills before I achieved my first hover :mental:

But great fun - and lets me indulge my wannabe aviator urge :)