ESC help needed

[Ray C]

I am putting axillary motors on my sailboat, and bought a 75a reversible "universal" ESC on eBay. I know nothing about ESCs, and was counting on getting some instructions that would tell how to set it up, and get me up to speed about ESCs generally. However, none came with it. Does anyone know of any good sites explaining of how ESCs work and/or how to set them up? I will be using a Spektrum DX7 system for control.

Thanks

[Umi_Ryuzuki]

Is it the little blue box?

[Hoghappy]

Ray...that brig don't need motors...use the wind...Luke! :p

Capt. Crash

[Ray C]

Thanks Hog. Some of us skippers need a little help, especially if you don't want to go swimming.

Here is a picture of the ESC I bought. Physical installation is straight forward, even I could figure that out, the problem is any programming or controllers to interface it to the Tx/Rx.

Description:
this brand new electric speed control works with any type of model boat and supplies up to 75 amps of continuous current when connected to your craft’s motor.

It also benefits from an auto cut-off function which cuts the motor’s power when the battery is low, so that power to the receiver is retained.

The inclusion of a BEC (battery eliminator circuit) enables the receiver to be powered by the motor battery.

Specifications:
Working voltage: 4 – 14 cells, 5V – 16.8V
BEC: 5V/1A
Auto battery cut-off: 4V
Continuous load current: 75 amps (backwards and forwards)
For use with brushed motors
Dimensions: 4.8 x 3.4 x 2cm
Weight: 65g

[Shaun Hendricks]

You will need to connect the ESC to one channel of your reciever.

That channel becomes your throttle, so pick whichever 'stick' or control you want on your radio and use that channel for the throttle. I highly recommend a stick control as forward and reverse is easy then.

Next, hook the motor leads to your motor.

Hook the battery leads to your main battery.

When you turn the ESC on, it will turn the receiver on.

Use your radio's trim setup to adjust for forward-off-reverse positions.

You are good to go.

This is the short version of how it works... :D

[Hoghappy]

Yip just like Shaun said. That probubly works like the one in my tug. Remember to already have your throttle where it needs to be on the transmitter when you power up...cause that is where things will start from. I have mine (throttle stick) pulled all the way down and can only go forward.... until I use the fine trim adjustment slider (which is all the way up to start)...when I pull it down (with the throttle stick all the way down) I get reverse. Does that make sense?

Capt. Crash

[Ray C]

Do you mean that the ESC when it is turned on takes the throttle position of the Tx as the center stop position, so forward is up and reverse is down from there (assuming a centered Tx throttle position)?

[Hoghappy]

Now why didn't I just say that?

You are correct...at least that's the way my ESC is that has no on/off or program buttons built in to it. It reprograms itself everytime you turn it on... to wherever the transmitter controls are set at... when you turn it on.

Capt. Crash

[Shaun Hendricks]

Some do, some don't.

The ones that don't have a pre-determined "min-point". If you have never set the trims before, it is possible for the motor to suddenly start in one direction or the other.

You dial the motor back to 'neutral' with the trim. Once it cuts off, go a little further and see if it starts the other direction. If so, set the trim between those two points for best control.

You might find you get better speed one direction or the other. This usually depends upon your motor. If it's advance timed (not neutral) it will run faster one direction than the other. Try switching the power leads and see if the motor runs faster the other way. If it does, then the motor is timed.

If it doesn't, that means that the transmitter or receiver is probably biased one direction or there's a limitation on the ESC. If it's biased to favor speed in reverse, you can reverse your motor leads and use the computer in the transmitter to reverse the direction. Then it should be biased to forward. If it's biased to forward already, you're probably good to go! :D

Not all ESC's are programmable or self program.

[Ray C]

Thanks everyone, I will wire it up and see what happens.