Can I fly with any of these items?

[Foxfan]

Gents,

I have been given the following and wondered if I could get airborne with any of them in whatever combination.

Emax CF 2812 11.1V motor, red anodised

TowerPro 2408-21T-3 (triangle symbol) motor, chrome bell shape

Slightly smaller motor with no markings in a pale blue anodiised finish

ESC "Flying" 20A BEC (marked 2-3 Li-Po/4-12Cell Ni, pale yellow shrink wrap

Similar sized ESC with plain unmarked black shrink wrap, also with Rx wire and plug.

TowerPro ESC, BMC 15A (Max 20A) LIPO 2-5 NIMH 6-16

Larger ESC in an extruded ribbed aluminium case, blue anodised, about 2"x1 1/2"x1/2", no markings, has Rx plug, a switch in a red/black wire and very thick cables

Zippy Li-Po 1300MAH 2S1P 8J 20-30C battery.

If there is any aircraft that would take any of this stuff, I'd like to know of it so that these generous gifts could be put to use to see if I like electric flight.

I am a beginner in modern R/C, flying and brushless electrics. I am an old hand in building stuff however and would want to make a suitable airframe in conventional balsa.

 

Thanks in anticipation.

Martin

 

Edited By Foxfan on 22/07/2013 16:54:32

[Pete B]

Re: TowerPro 2408-21T-3 (triangle symbol) motor, chrome bell shape - is this the motor, FF? Some useful prop/battery info if it is. Either of the smaller ESC's would be fine, I think. Perhaps something along the lines of a Piper Cub or similar high-winger, about 40" span, 16oz AUW?

The Emax motor is a little more powerful so might suit something a similar size but a little more sporty?

Edited By Pete B - Moderator on 22/07/2013 17:41:28

[David Tweddle]

Hi Martin can the Ladies also answer...

David

[Foxfan]

Thanks Pete, interseting size and useful as I only have limited storage space and a wee car. I'm a scale man too, so bigger rather than sportier might be the way. If not bigger then heavier by a bit?

What about the Li-Po? It doesn't say how many volts it is.

David, ooh, sorry, I knew that would get me into trouble!

Martin

[WolstonFlyer]

Hi

The Emax CF2812 could be used on a 6mm depron park jet like this F22 Raptor with either the 15A or 20A ESC.

***Link***

I made this F22 it is very nice to fly, eventually smashed up by my 9yo Son.

Oh and the LiPo you mention is a 2S so the max voltage will be 8.4volts, ideally for the Emax motor you want a 3S Lipo. For info 1S (1 cell) has a max voltage of 4.2 volts.

Edited By WolstonFlyer on 22/07/2013 20:49:41

[Foxfan]

WF, that's certainly different! But I have no idea what to do with foam, don't do military and hate profile. I was never happy as a kid with the KeilKraft Champ!

But as an example of performance it helps no end. Same-ish Li-Po too.

So, it would appear that if I build nice and light (pound and a half?) the Emax with 195Watts apparently, should be fine at the rule of thumb of 100W per lb. Maybe a floaty scale jobbie at 2lb?

This excellent as all I need is a suitable charger, now.

Many thanks, all of you, ladies included if any!

Martin

[PatMc]

According to the BRC site the Emax 2812 is 1500KV, the maximum current for 30secs is 15A & constant current is 10A. This means that on 2s lipos 30 sec max power would be about 110W for 30secs & 75W constant. On 3s power would potentialy increase by 50% but on a smaller prop.

Basicaly the motor is fast reving best suited to a small fast flying model.

[Foxfan]

PatMc, that website says an 8x5 prop for 85 watts. Would that be OK for a slower model? Any idea what the battery is? Does 2S mean 7.4 volts? It says 11.1V on the motor, or is that a maximum?

Thanks,

Martin

[PatMc]

Hi Martin, if the BRC figures are reasonably accurate then an 8x5 running on 2S lipo should be OK for a light vintage type model.

2S lipo means 2 cells in series, each cell is nominally 3.7v but when fully charged usually 4.2v/cell. However under load the voltage seen by the motor is lower, the actual voltage depends on the load (size of prop) & the current that the battery's capable of handling. A good approximation for a decent battery under moderate load is about 3.6v/cell.

There's no actual maximum voltage (or wattage) for motors however as you can see by the size difference in props when using 2S & 3S with this motor a voltage higher than 11.1v would necessitate an impractically small prop.

[Foxfan]

That's great, Pat, thankyou. I rather like the PixE Major. I had 2 KK Pixies when I was lad. My Uncle made them both for me and my Mum sat on them! How can anyone not see a model on a chair or my bed, but crunch and they were gone! Her young brother didn't speak to her for weeks!

I'll try to get an old KK plan and enlarge it as my experience of myhobbystore's plans (what a STUPID name) is that they are appallingly badly drawn for the money, so I will do my own, but the PixE confirms it can be done and I will Austerise it to go with one at my full sized flying club.

Thanks again,

Martin

[Pete B]

Sorry I disappeared last evening, FF - modem problems - I was cut off from the world....

You seem to have had your questions more than adequately answered by the other good folk here, so all I can sugggest is that, if you haven't already, it is worth having a browse through the threads on the Electric Flight section, such as the threads here.

Plenty of useful info there - and if you have more questions, just ask

Pete

[Pat (rActive) Harbord]

Posted by Foxfan on 23/07/2013 00:48:26:

they are appallingly badly drawn for the money, so I will do my own, but the PixE confirms it can be done and I will Austerise it to go with one at my full sized flying club.

Thanks again,

Martin

Tim Hoopers PixE plan is excellent and there's a build article if you need it

[Foxfan]

Thanks rActive,

After wasting my money on the Hornet Moth drawing I am very wary about buying new drawings from that source, I had to redraw it, just to make it even work! And I've read comments where the original designer has had to admit that what myHobby store do with them is beyond his control.

I have also downloaded a few likely ones from Outerzone to have a peruse through.

Somebody said the motor would suit a sportier model and I have always wanted an R/C version of the lovely old KK Skystreak 26. Could that be converted for R/C I wonder? Only once I've gained some confidence, of course!

Martin

[PatMc]

The August 1986 Radio Modeller had a 32" span RC version as it's free plan. I have a copy somewhere in the loft but I won't be able to locate it for a while. Maybe someone tha keeps the old mags & is more organised can help.

BTW original RM version was for an 09 so with modern gear to keep the weight down a 3S lipo with the Emax should be more than adequate but not blistering.

[Foxfan]

Pat, thanks. I am not yet ready for blistering, apart from in the Sun!

My old octagenarian chum in the village has magazines back to the 70s if he can find them, so I'll ask him if there's a chance of finding that mag, out of interest. He designs all his models (over 50 now) and will give me the low down on my mistakes, but like me he knows nothing of electrics and steadfastly refuses to switch. I guess when you have drawers full of Lasers and petrol engines you can leave the amps for the radio gear.

Martin