3drupture

Im building a very large sea plane..(4) 46 size outrunners to power it..Its a 12 foot span and very light plane..Im wondering if I can run 4 ESC`s off one receiver.I wouldnt think it would be a problem.Has any of you done it?..

Walt Thyng

My Feedback: (9)

I, personally, have never done four, but I have seen it done. The most I have ever hooked to one rx is two escs. On a bird that large, I assume you are going to use a separate rx battery, so you will need to disable the BEC function if your ESCs have it. Simply pull the red wire out of the rx plug and insulate it. Some people use a short extension cable and cut the red wire. Either way works.

If you do want to use the BEC function then disable all but one of the leads.

As long as the BEC function is disabled its not different than plugging in four servos.
Walt

3drupture

Thanx,thats pretty well what I was thinking on it..I will probibly run a sep. rec. battery.Weight is not going to be a problem.Its looking like 15 pounds with batteries.Over 1000 sq in. of wing area.

John 38

On multi brushless motor/esc systems, how precise are the individual low volts cutoff- ie if you run model long enough to initiate cutoffs, will you get individual esc's shutting off causing asymetric power.

on a 2 motor model with motors relatively close in, I suspect that will be less of a problem compared to a 4 motor and an outside motor shutting down first.

not fatal at height and you realise what is happenning, but bad news on landing approach

brushed motors driven by one esc - no problem

any comments on this from the the more experienced guys ?

john

Walt Thyng

My Feedback: (9)

John is right about the cut-off voltage. Even the best ESCs may vary. I handle the assymetric power problem two ways. 1)all motors have 2-3 degrees of outthrust. 2) I time my flights and (hopefully) never get to low voltage cut-off.

On my B-24 project I ahve the two inboard motors (brushed) on one ESC and the two outboard motors on a second ESC. They will all draw from a common battery.

Walt

3drupture

This is why I an going electric on this one..I have a large Lancaster Bomber thats running on 4 glow motors,most of the time its fine and sounds oh so good..Then there is times I lose motors while flying.On electrics,I normally run large enough batteries ,I have never had one shut down on me..I also run standard props with very good results..One of my motors is an e-flite 450 outrunner.Its running an APC 4 blade 9X6.Not an electric prop..The plane is very fast,motor loves it and Im getting around 20 minutes on a 11.1 X 2200 mah pack..3 cell lipo..The motor is cranking around 9,000 Rpm.The type of 4 engine plane Im doing right now needs no right thrust on the motors,it got a unique setup to this type of plane,just like the full scale one..The engine nacells stay parallel to the sweepback of the wing,so they all point outward away from the fuse.I read about it on the full size bird and its suppose to work..lol..We will see..The plane is called a Sunderland II..

Walt Thyng

My Feedback: (9)

Hope you post a pic or two.
Walt

3drupture

ill put a pic of it in my profile 2nite.Its not done yet but is mostly done..

gleebs

Yes the motors will cut out at different times and the simple fact that one motor cuts makes the other last even longer because of rebound in the batteries once that extra draw is off it. Low voltage cutoff shouldn't be an issue as you shouldn't be flying til you hit it. I fly my stryker to LVC but it glides easy and lands slow. You wouldn't fly a glow til you ran out of fuel would you? You could just Y-harness then Y again, but I would make my own 4 way because I don't like a lot of extra plugs. E-meter your amp draw to calculate how long your battery will last. For example on a TP3300, 3.3Ah/45A draw = .073333 x 60 = 4.4 min or you could do it this way 45A/3.3Ah = 13.636363, 60/13.636363 = 4.4 min. You will lose some power due do inefficiency, and heat lose though the battery so start at 75% of that and see what you have left.