pmk01

First off, I'm using a Spektrum 7 channel tx and a Spektrum 6 channel rx. I'm using 2 servos for the 2 rudders and 1 servo for the nose wheel. Somehow I don't think I can use 2 y harnesses, one side for the nose wheel and the other side for the other y harness and 2 rudder servos. If programmable mixing, which I know nothing about, is the answer, then I will find somebody locally to teach me that.

The second thing that is blowing my mind is, I'm using 2 batteries, one in each boom, Turnigy 2200 Mah 3s 20c, (2 ) 40amp escs, one in each boom and 2 Raiden 500DF motors with a 3 blade 9 X 7 counter rotating prop setup (yet to be watt tested). You once said you could only use one esc to power the elecyronics. How do you do that?

Thanks in advance,
pmk01

opjose

Re: Rudders

Yes using a separate channel for the nose wheel and the rudders is not a bad idea. This gives you the ability to separately adjust and tune the nose wheel position as needed. It is my preferred way of doing things.

On the ther hand there is nothing wrong with wiring up both rudders onto a Y harness and hook that to yet another "Y" harness to supply a lead to the front wheel. However this makes setting up your linkages a bit more complex and you have to have the nose wheel control horn linkages in the right place for the amount of wheel movement you want... remember when it comes to the nose wheel MORE movement is not necessarily better!

Re: Packs

You can indeed wire one battery per ESC and motor if you wish. However realize that this may result in a situation where one pack runs down before the other, and the plane may yaw in flight in response to this, making landings difficult.

I prefer to wire both packs in parallel, then feed their output to both ESC's in parallel. That way BOTH packs supply BOTH motors @ 11.1v.

When the packs run down, they will do so evenly and both motors will pull the plane through the air evenly.

Also by wiring your packs in parallel, you are effectively temporarily creating a single 4400mAh 11.1v 20C back to drive both ESC's.
The combined pack actually has better electrical capacity, so you end up with lower battery strain, better flight times, and more even flight characteristics.

Re: Power to Electronics

When you use TWO ESC's like this, you remove/disconnect the RED wire from the ESC's connector on one of the ESC's.

The red wire is the voltage wire FROM the ESC to the electronics.

The best way to do this is pick up one ESC, find the throttle lead. Use an X-acto knife to LIGHTLY pry up the retainer clip on the plastic lead cover, and gently pull out the red wire with the gold pin attached.

Wrap the gold pin in shrink wrap and heat ( preferred ) or wrap it in electrical tape ( danger may come off in flight! ).

However 11.1v 40A ESC's tend to max out at handling 2-3 servos, and on occasion 4.

You already listed a servo for each rudder, one for the elevator, one for the nose wheel, and you likely have one for each aileron.

That's SIX servos!!!

In a situation like this you are best off taping off BOTH of the power leads from the ESC's and using a separate BEC wired into the connectors to the battery packs.


How are your soldering skills?

It sounds like you have a good bit of soldering to do to get everything ready.

I can spend a whole evening soldering up all of the connectors for a single multi-engine plane...

pmk01

Thank you, I really like the way you answer these. You're very knowedgeable and patient with people. You explain things very well and don't make people feel stupid. I do have a bec kicking around somewhere, but I've never used one before, I'm very new to this. (Don't worry, this is not my trainer.) It's going to be fun trying to figure out where to fit the bec though. Also, I was a government approved solderer for 15 years before I retired, so I should be ok.

Thanks again,
pmk01

opjose

In the following photo I wired a BEC between the ESC and the battery pack.

The BEC is the little black and green circuit board on the right hand side of the fuselage, mid-upper part of the picture.

The BEC is not "in-line", but rather draws power from the main feed wires, much like the image below this one.



Here is a setup I use for Deans connectors...



This permits me to easily transfer the BEC to another plane later without having to rewire anything.

Note the tag that reads "input 5-30v". The other reads "Output 5v".

On other option is to disconnect both the BEC's on each of the ESC's and just use a flight battery to power the servos/electronics.
If I'm trying to save weight, I'll normally opt for the BEC.

pmk01

Thanks for the extra info & pictures, it was very helpful.  My extension wires for the batteries and escs might be kind of long when I wire them together. What Gauge should I use?     Also, my bec has 2 output wires and plugs, what do I do with those, do I only use one plug or what?
Thanks in advance,
pmk01

opjose

The wires from the ESC to the batteries need to transport a lot of current under normal circumstances.

These should be fairly thick core wires to provide the least resistance, and best power handling.

I use 12 guage or thicker from the local hardware store. Likewise I'll use 4.5 or 4.0mm gold connectors ( as in the the picture ).

Re: BEC

Could you post a picture of the BEC ( upload it to your gallery then post the link to your gallery picture )?

Normally BECS have only two sets of wires, one to the battery/power points, the other to your receiver.

pmk01

Ok, here's the link. The output is the lower right picture. These pictures were not taken by me and were from the hobbyking.com site, but that is the bec I have.
http://www.rcuniverse.com/gallery/ga...%26clubgal%3D0

Glacier Girl

My Feedback: (4)

The bec has two output connections because of it's listed amp output. The standard servo plug is only rated to a 5 amp load, so they added a second lead. Which if this truly can put out 15 amps, it should actually have three leads. Anyhow, you can plug them directly into the receiver if you have empty sockets, if not you'll need to install them into Y leads going to some other servo in the plane. One lead to each separate Y lead.

leadtongue

Use two of everything...motors...esc's...rx....batteries(2 in parallel in each boom). Cuts down on all the y harnesses so that buying that extra esc or rx isnt so costly! i have the same plane...with 2 monsterpower 25 motors...2 eflite 40amp pro esc's and 2 spectrum ar500 rx. 2 2200mah lipos in each boom for a decent flight time of about 11.0 minutes! It comes in just over 5.25lbs auw . i went with larger motors so in case of a motor out situation the 25 should have enough thrust to get her back down safely. Its a nose heavy design with little room for batteries. I have to mount 1 batterie just behind the last bulkhead in the nacelle tray to get cog correct!