An electric set up - by Ralph and Chris

[Tim Mackey]

Thanks to Ralph Yeates and Chris Ireland for this Illustration of how the basic components of an electric set up go together - Clicking the picture should enlarge it sufficiently to be able to read clearly.

The Deans style connectors shown are of course an option, other suitable plugs are available such as "Gold Bullet" connectors.

[Former Member]

[This posting has been removed]

[IanN]

I'm dabbling with my first (bottom end cheapo) elec set up. When connecting the three motor wires to the esc is there any best way to get that right first time?

 

LMS tells me its simply a matter of trial and error until you get the desired result? Is that correct - wouldn't want to join the wrong bits and have smoke signals..............

[Former Member]

[This posting has been removed]

[George 1947]

Hi

 

How do install a model on/off safety switch in the set up?

 

Thanks

 

George

[Aero120]

George, generally you don't need to. The battery needs to be easily accessible to recharge or replace after each flight, so you just usually plug it in before you fly. If you really do need a switch then it would have to go in the main power supply from the battery and so would have to have a high enough current carrying capacity to suit the motor. Some people use an isolator plug under an accessible hatch to break the circuit when its removed

[Tim Mackey]

Heres how I did it on a Sopwith camel recently.

Deans plug inline with main battery +ve lead - I dont usually fit any switch at all, and do as Paul suggests, but this particular model has fixed LiFEPO4 cels, so I needed quick access to inmodel charging ports too.

 

[BB]

Photo = 1000 words.  Very useful, that.

 

BB

 

P.S. Pic wouldn't enlarge though.  Clicked till me 'mouse' snuffed it !  

[Tim Mackey]

Works OK for me BB

[Bruce Richards]

Works fine for me too but I have had some problems expanding pictures in Firefox with certain ad-ons.

 

Edited By Bruce Richards on 26/10/2009 19:04:44

[Streetburner]

When connecting aileron servos to receiver it says connect right one to aileron & left one to aux1 on receiver. DX7 tranny. When I switch on etc, only one works when stick is moved but power is to both what am I doing wrong or should I fit a Y lead and connect both to aileron on receiver. Was trying to avoid doing this (more wires) 

Help appreciated still learning.

[Tim Mackey]

Errr your crossposting mr burner - please dont - theres a good chap

[Mike Downs]

Hi,

 I don't  know if i am in the right bit of the forum to ask for advice....but here goes

 

I have a twin powered Copncorde model   58 0z in weight powered as follows

2x Mega brushless Acn16/15/6

2xJeti 30-3P speed controllers

1xPelican11.1V 3400mA pack

2x7x4 props

The above gives me 12 oz of thrust

Using a watt meter (which I am not sure how to use properly) the Watt reading is 45

 

Changing the props to 7x6 gives me 23 oz of thrust

The watt reading is now 62

 

The question is if this elevated reading would do damage to the speed controllers or the battery.

Cheers

 Mike D

 

I I have additional info to the above 7x6 set up

 

The readings on the watts seem to change every time I throttle up to max

 

Volts vary from 7.42 to 7.8

Watts vary from169 to 174

Amps vary from 17 to 21

It is a Tornado Watt meter...... is this ok?

Edited By Mike Downs on 08/03/2010 14:15:03

[Tim Mackey]

Well firstly the larger pitch prop is understandably pulling more current. If the new figures are 62 watts, and your using a 3s pack, then equates to about 6 Amps only! The ESC are rated at 30A and the motors will take way more than that .

I suspect you have some incorrect readings here somewhere, and for a model weighing over 3.5lbs, you will need around AT least 350 watts not 62 .

[Tim Mackey]

The second part of your post is also erroneous.

A fully charged 3 cell lipo should be showing around 10.5 -11V  under load ( in use )

You say the watts read from 169 -174 yet earlier you said the watts were only 62 ??

You also say the amps are 17 -21 yet again, before, it would have been about 6

[Tim Mackey]

That motor ( 1500 Kv ) on 3s with a 7X6 prop will probably pull about 11 -12A and therefore produce about  110 -120 watts -so together, the two of them will be about 200+ watts.

You really neeed either bigger props, or higher Kv motors, or more volts to get the power you will need.

[Mike Downs]

Thanks all,

  I cannot understand the variation on the meter readings....I must be checking it wrong so I will describe what I have done so far.....

 

I have the watt meter between the battery and when I switch on the plane the readings are as follows;

       V                    W                  A

    11.6                 1                   0.1          No load

     I have taken 5 readings as follows

 

   7.52                  60                 7              Full throttle

   7.61                 97                  13                    "

  7.66                  118                16                   "

   7.7                    167                20                  "

   7.9                     190               23                  "

 

  I leave it running for about 10-15 secs As you can see the voltage always drops down

 when at full throttle, but that is the only consistant reading of them all..

 

  Could anyone tell me where I am going wrong

  Cheers

 Mike D

[Mike Downs]

 I have a sketch of the wiring and location of the Watt meter....to go with previous posts

Wiring diagram to go with previous post....Cheers

[Tim Mackey]

OK first off, your battery should be reading at least 12.5V off load.

second, as already stated, no way should the pack be dropping down to 7+ V under load - I suspect your battery is either....

 

a) goosed

b) not charged correctly.

c) both

 

The power figures "add up correctly"  however, I dont understand the current figures....there is no reason why it should vary so much. A little fluctuating is normal, but these figures are way off.

[Tim Mackey]

Yep, the meter is in the correct section of the circuit.

[Mike Downs]

Cheers Timbo......I will check the battery and get back to you

[Mike Downs]

Hello again,

 

   I suspect it may be (c).I am recharging at the monent.....meanwhile a few more questions.....

 

When testing how long do you leave it at full throttle?.

How much varia5tion in readings are typical?

The wattmeter has mA counter,,,What is this for?

What could the reduction of voltage readings be due to?

Will temperature be a factor? (Cold Garage!)

 

Cheers

 

Mike D

[Tim Mackey]

I usually leave it for around 45 seconds...this gives the pack a little time to warm internally and perform better.

 

Variations? - well not withstanding variations between different meters, expect to see the voltas fluctuating up or down by mayb .25V or so and the current an amp or two at decent levels.

 

Consumed m/a - IE how much juice you have taken cumulatively during the run.

 

Duff battery? - although those are good quality cells - Puffin models by any chance ?

 

Yes, but not to that extent.

 

 

 

 

[gary w]

Must agree Timbo battery defo duff battery or the c rating is wrong

your only running a 2s pack not 3s.

I would try each motor separtely and get the reading's.

but with a fresh 3s pack at least 3200mah 20c min..

Edited By E-Flight on 09/03/2010 20:57:54

Edited By E-Flight on 09/03/2010 20:59:58

[Mike Downs]

I have sent away for a couple of new batteries.......will get back to you with the results

Cheers