ESC are they different?

[Erfolg]

I require two ESCs, that are essentially required to act as a full power switch, then provide course throttle control, along the lines 2/3rd maybe half.

 

On the intranet I find many ESCs that appear to fit the bill. In that they have 3 wire motor wires, and a 3 wire Rx lead.

 

What appears that it may be an issue is that they are described along the lines, as for car, for truck, for boat, for Quad, non seem to say fixed wing use.

 

Do these applications differ materially from my purpose or model aircraft requirements

[leccyflyer]

Notwithstanding the requirement to only have a throttle control to give Off,2/3rds and full power then to answer the question - Yes, there are different ESCS for different applications. For flying a fixed wing model you don't want car, boat and truck ESCs, which will be typically be equipped with a reverse function, that you don't want, You don't want a quadcopter ESC, which may provide additional complexity and programmability. You just need two standard air ESCs for brushless motors, like these one - though of course sized appropriately for your power train.

 

Edited October 16 by leccyflyer

[Cuban8]

50 minutes ago, Erfolg said:

I require two ESCs, that are essentially required to act as a full power switch, then provide course throttle control, along the lines 2/3rd maybe half.

 

Why the coarse throttle control? Would the usual linear response be no good for your particular application? I suppose you could set up a throttle curve to achieve a more stepped response.

Just curious.

[Erfolg]

I am building a Df model that has 2 ESCs, although I do not think having two is an issue.

[john davidson 1]

Plugging two into the throttle  may give odd results. One way to avoid  is to slave one to an unused channel, gives a tiny delay but not noticeable in practice. As usual disconnect one red wire.

[Erfolg]

My interpretation of your post Leccyflyer, is that a quad is potentially OK, although offering more than is necessary.

 

Boats, car and truck could be an issue having potentially a reverse function as part of the throttle range, without being switched in some way?

[leccyflyer]

I'm suggesting just Keep It SImple and use the tool designed for the job. We're seeing fixed wing models with reverse thrust capabilities to assist with runway braking or even reverse taxiing - that is far from the norm and not something I'd recommend.

 

I don't have any stand alone quadcopter ESCs, so don't read too much into my reply, but can't see any real benefit in using one for the application that you are wanting to fulfil. There really is no need to complicate matters unnecessarily. If you are wanting to build a twin EDF with brushless motors you need two identical air ESCs one for each motor. AS John said, if you are using BEC equipped ESCs you should disable the BEC on one of them by disconnecting the positive red lead. The easiest way to do that for your application is to lift the tang on one of the positive leads on one of the ESCs and tape it back against the lead. You can choose to use a Y lead into a single throttle channel or, as John said, you can slave a sperate channel to throttle,

 

You'll also need to decide whether you want to parallel up the flight batteries. Received wisdom is that if the engines are far apart then there are significant benefits in using either a single large battery or two batteries connected in parallel, thereby reducing the risk of one battery running down too quickly and producing asymmetric thrust, if each battery feeds just one motor. Some say that if you're flying an EDF where the two fans are right next to each other that is less of a concern,

[Paul De Tourtoulon]

2 hours ago, john davidson 1 said:

Plugging two into the throttle  may give odd results. One way to avoid  is to slave one to an unused channel, gives a tiny delay but not noticeable in practice. As usual disconnect one red wire.

I use a helicopter mix, motor for one, second motor on Pitch, ( Futaba channel 6 )then use the mix  to synchronize the rpm.

[Simon Chaddock]

Erfolg

I have several multi EDFs.

In all cases I kept it simple and connected all the ESCs but only one of the red wires connected to the throttle channel. I did go through the throttle calibration routine with each ESC individually so that they would all start at the same throttle position.

The four EDFs of my AN124 under test.

https://www.youtube.com/watch?v=aAjHFUb3ot4

They all started together and at full power ran very close to the same speed. You can hear the slow beat of the near synchronisation.  

[Erfolg]

Simon

am not c

I have a Bf 110,  used ti have a twin Delta (which you may have seen) moderating a twin is something that in itself not new, to me. At present it is not the issue. 

 

What I am not comfortable with is DF, that really means I have no experience, or real knowledge.

 

As suggested (I think by Leccyflyer and our working background) I like simple solutions. In this case limited capability, seems the starting point.

 

I have received much useful information from these posts already.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Robin Colbourne]

We had George from 4Max give a talk to our club the other day.  He made a good point that if an ESC burns out in flight, which they do on occasions, if the receiver is powered from it, you may also lose flight controls, whereas if you use a separate UBEC, you will still be able to control the model, so at least have the opportunity to do a controlled dead stick landing.

[john davidson 1]

I used a quad esc in my Sunderland thinking it would simplify the wiring. In practice the wiring through the wing was  three wires times four and contributed to a heavy wing, flew well though

[Paul De Tourtoulon]

Dare I admit that My Lancaster only has 2 esc's, one for the outside motors the other for the inside ones, 2 x 3s battery's the only problem is starting up the motors, if you are too quick only one of them will start.

[Simon Chaddock]

Indeed, one ESC to two brushless motors (but no problem for brushed) is far from ideal. Apart from the initial starting issue there is a danger if you shut down in flight, which is the big benefit of electric, they may not all restart.

A brushless ESC has to "read" the motor back EMF tens of times a second to time when to send the next pulse. With two motors each sending a back EMF unless the motors are a perfect electromagnetic pair (unlikely) the ESC will not send the ideal timed pulse for both motors. One or both of the motors is likely to be operating at below optimal performance.

Just saying.