Hi Jake,

Treat your self to a new ESC the old one sounds like it has expired 😀

Mtronics are pretty good in my view 👍

Regards Ray

Yes, basically! an Mtronics one will do forward and back. What size is your motor, assuming it is not marked up?

Ashley

Tricky, unless you can find out what the MFA speed controller spec was, or someone here knows.

In theory you could buy a wattmeter (not expensive), plug it between batt and esc, put the boat in the water and apply full power to see what the motor pulled current wise. Not very scientific, but..

I don’t suppose the motor will have been very powerful if that old. Could get a ,say, 25A esc, fit a 20A fuse and test. Can’t imagine the motor would be that juicy. Possibly an MFA motor was fitted as you have an MFA esc, and even a Marlin (I believe it was, the forerunner of the 800/850 motors) would not break 25A. how big is the prop? Just in case it might overload the motor.

I am probably talking nonsense and DM will have all the specs to hand but that’s the way the cookie crumbles!

Ashley

The great thing about modern electronic speed controls for brushed motors is that one that will handle a big motor will handle a small one just as well, so one that is rated for lots of amps will control a motor that doesn't need much current.

Wth early ESCs (going back to the previous century) a general limit was 10 or 15 Amps in quite a large package, because that was the limit of the transistors on the market. Times and tech have moved on, transistors capable of much more current are available in much smaller packages. It is still important to look at the ESC's rated voltage and make sure that it can handle what the battery is going to offer.

Hi jake,

Sounds like a Taycol motor, I have one, absolutely no idea how it works or how to wire it up, yes 1960's finest 😀

Regards Ray

There is a website dedicated to Taycol Motors . If you cant find an answer to your problems on the site – the owner of the site is very helpful and knowledgeable – sure he would be able to help sort things out for you.

Site address is taycol.tk – . Easily found with google search by using Taycol Motor Website UK

Do believe you have a very collectable motor there

The diodes are to allow the current to only go where it is needed. The original, un-dioded version required that the battery supply would be connected to either the forward or reverse terminal through a switch, either manually operated or controlled by another channel.

As originally supplied, no matter what the direction of the current, the motor would always spin the same way and only changed direction if the current was passed via the other terminal to use the other field coil. Thus it needed a controller for speed on one channel and anothe control channel to operate the switching device.

A modern ESC reverses the current according to the information on just one channel, which for this type of motor gives a choice of forward or forward. Each diode directs the current to the right terminal for the wanted direction of rotation. Instructions in the link that both I and redpmg pointed you to.

On most boats, suppression is done by capacitors. Modern motors with just two terminals, one component across the two terminals is usually enough, but some theoreticians insist that an extra two are needed between terminals and case. A field wound motor will need two capacitors, two on the common terminal with their other leg going to the other two terminals. A Taycol will benefit from a shot of oil on its brushgear and commutator, unlike any other motor.

I suspect that back when the "new" ESC was installed, the required diodes had yet to be invented. The MFA box might still work, but there is no saying what might have happened to it while the attempts to get it working with the wrong type of motor. A pair of Schottky diodes of at least the current capacity of the ESC that you are going to use are needed. No need to bother about their voltage -the available ones start well above the voltages that are found in model boats.

Just theorising, but no reason why it shouldn't work that I can think of.

There will be limitations, I am guessing from the number of terminals that it is as series wound motor. I only touched briefly on the things when doing my C&G studies a long time ago, but power dropped off considerably as current was reduced – it was a lose-lose situation. There was something about them behaving badly when fully powered if run unloaded, but thats back in the fog of time.

A motor, to drive, needs the rotating armature electro magnets to push against the fixed magnetic field. With a strong permanent magnet, this field is always the same. With a wound field, as the current drops, so does the power available in addition to what is lost to the moving coils because they have less to push against because the field coil has had its power cut.

So while it will work, it will almost certainly have different characteristics to a modern motor.

The servo operated reversing switch need be little more than a piece of copper clad stripboard under a wiper attatched to a servo arm arranged so that at one end of the servo travel, a common strip is connected to a length of copper strip going to the F terminal, at the other end of its travel, to the R terminal. At the mid point, nothing is connected, so you get an "off" position. Mechanically connecting a switch so that it both works and can't do either the servo or the switch or the mounting gets complicated.