ESC ? BEC? HELP !!!!!

[Bad_Boy_666]

Ok, I understand that ESC is probably the best way forward if I am going to run my vintage models.

I also understand BEC (battery eliminator circuitry) or I think I do. My hotshot was always going off on it's own when the batteries were flat and i broke several parts in my youth due to this.

It also happened with my rebuilt Boomerang as I watched in horror as it dissapeared up the road, accross a grass verge, over the main road (luckily without any traffic) and into someones front wall, breaking the suspension mounts!!!

Now I am pretty sure that neither the Sanwa or Futaba recievers I have got have BEC. But both speed controls have a separate on/off switch. Am I right in assuming that I don't need BEC in the reciever because it is already present in the form of this switch ? I haven't had to wel on any extra wires on or anything. It all goes together as it says in the manual. So where does this BEC come in ??

 OK. also if I put in an ESC, am I right in assuming I dont need the one Servo because this replaces both the old MSC and the Servo. Does this now mean I don't need the On/Off switch ?

How does the Motor correlate back to the type of ESC I will be using ? If I use my Mega Motor 18 x 2 turns, will I have problems? And what is the different between 18x2 turns and 18 turns ? Is this the same as running 36 turns ?

Any help appreciated. I don't want to see my rebuilds running up the road on their own again!!!!

[rhenbelz]

The receiver will say BEC on it if it does support it. Don't use an ESC with a receiver that doesn't support BEC.

The ESC will have its own BEC current, provided by powering the receiver through its connection to it. The exception is the TEU-101BK, which has its own separate connection for it. 

Don't mess with the ESC's switch, as it has a completely different function from the old MSC ones. An ESC switch just turns the ESC on and off, unlike in the old days where the switch specified whether the receiver was powered or not.

So just put in a receiver that supports BEC, an ESC, and don't worry about changing anything.

An 18x2 motor is a motor with 18 turns of wire, with a double wind. All you need to worry about is the 18, and match up your ESC with that. I assume you know the basics of ESC-motor correlation.

[Bad_Boy_666]

Ok thanks, I think I understand. Reciever is useless, however it was used in my MSC set up....I take it this was wrong.

So the BEC is in the reciever and a A BEC switch is just basically an off switch for the reciever. My reciever is a Futaba FP-R102GS I cant see BEC on it anywhere. I shouldn't use this with my MSC and switch then ?

This was how I used to run the car.......still a bit confused.

Also I don't know about ESC-motor correlation. I know there are limits on the number of turns on the motor an ESC will take. I.e.the Teu will only go down to a 25 turn? so my 18 turn is too low. I don't know why. Is this something to do with current drainor something?

Note.....Just looked in the manual....the speed controller comes with a Reciever Battery Eliminator. Does this mean the reciever does not need to be BEC because the switch is BEC and therefore eliminates this problem ?

[HunterZero]

Radio gear runs on 6V DC. BEC is just a voltage limiter to allow you to run a 6V receiver with >6V main battery. Eg, when using a 7.2V or 8.4V main battery, it steps down the power to the receiver to 6V. So you can then power the radio gear from the main battery of the car, usually from a connector on the speed controller.

Old receivers do not have BEC, and those that do have a 'BEC' circle logo on them. If it doesn't say BEC anywhere, then it is safer to assume it does not support it, and probably won't like it if you supply it with more than 6V.

In the early days of BEC, you could get a special power switch unit with BEC built into it that effectively added BEC support to a non-BEC receiver. These look like a switch on a small circuit board, with a blob of black epoxy covering the back. To install it, you removed the receiver battery pack and its wire connector to the receiver (which includes a power switch), and then connect the special BEC switch unit from the 2-pin red connector on the MSC to the power socket on the receiver.

These days, the ESC plugs directly into the receiver, and either supplies power through the throttle channel plug, or through a separate connector into the receiver's power connector.

You CAN use an electronic speed controller with a non-BEC receiver, you just need to make sure the ESC itself has the BEC, or you can cut/disconnect the power wire from the ESC to the receiver and use a receiver battery pack. Most ESCs these days do have BEC and will work just fine with a non-BEC receiver, however a few do not, eg, the TEU-101BK ESC does not have BEC.

Most ESCs have a receiver power priority system these days, so when the main battery runs down, it makes sure power still goes to the radio gear so you don't lose control, and so are worthwhile for this reason.

- James

[Backlash]

Don't mess with the ESC's switch, as it has a completely different function from the old MSC ones. An ESC switch just turns the ESC on and off, unlike in the old days where the switch specified whether the receiver was powered or not.

rhenbelz, if what you have said here was true, then the receiver would be turned on whenever the cars main battery was plugged in. I am yet to find an ESC where this happens.

Bad Boy.

An ESC's switch does turn off the power to the ESC, and also the receiver and steering servo. Use the ESC's switch in the same way as you would the original switch in the car.

I agree with the advice that HunterZero has given you. The BEC, (BEC stands for Battery Eliminator Circuit) that is inside most modern Receivers is actually located between the battery input socket, and the Channel 1 and 2 output sockets on the receiver. When you connect your new ESC to the receiver, you connected it to the 2nd channel output, and this is where the ESC supplies power to the receiver, so in doing so, you do not connect through the BEC in the receiver anyway.

The only exception to this rule is the TEU101BK ESC, that does not have an inbuilt BEC. This cheap unit does not supply power through the channel 2 connector, but has a second lead that supplies 7.2 volts from your running battery, to the battery socket of the receiver, and then the BEC in the receiver cuts the voltage down to under 6 volts.

With your Hotshot, Do you run 4 AA size batteries in the car, or is there a small circuit board of about 15mm x 20mm under the existing switch? If you have the small Circuit Board (this is the BEC that HunterZero spoke of) on your switch, and NO AA batteries, then you could connect the battery plug off the TEU 101BK into  the input to the BEC (BEC input is where the where the BEC wires connect to the old MSC) , then leave your original switch connected as usual. Obviously, you will then have 2 switches in the car, just leave one of them turned on all the time, and use the other to turn the car on and off.

OK, If you want to run an 18 turn motor, then the TEU-101BK (Tamiya ESC) will not be any good, because as I understand it, its only rated for the kit standard 540 motor, and the Sports tuned motor. Modern ESC's are rated in motor turns, and the less turns a motor has, the faster it will be, and the faster your battery will go flat. What you will need is an ESC with a turns rating smaller that that of your motor. So basically, an 18 turn motor work just fine on an ESC with a 15 turn rating, BUT you CANNOT use an ESC with a turns rating of 18 turns, with a 15 turn motor.

 Please, if you need any more help, just ask. Remember, the only silly question is the one you dont ask.

Goodluck.

[rhenbelz]

Don't mess with the ESC's switch, as it has a completely different function from the old MSC ones. An ESC switch just turns the ESC on and off, unlike in the old days where the switch specified whether the receiver was powered or not.

rhenbelz, if what you have said here was true, then the receiver would be turned on whenever the cars main battery was plugged in. I am yet to find an ESC where this happens.

Not what I meant, I mean that the ESC is turned off as in it's what runs everything. Obviously you have to have the ESC in place to provide power to the receiver. I took that as given.

[Bad_Boy_666]

Thanks for the comprehensive advice.

 Just to make sure.....the Acoms switch that I currently have doesn't have a circuit board on the back. The part number is AC1 Power Switch (BEC) Battery Eliminator Circuit

Does it have BEC in it ? and therefore I don't need a BEC reciever or do I still need to buy a new reciever ?

Thanks

[rhenbelz]

It'll work fine. It's up to you how you want to hook everything up.