Esc for motors

[David Smith 52Participant @davidsmith52]

Hi All

I am a long term aero modeller, but my son has recently got into boats. He has a Hobby Engine , Richardson Tug boat.

The boat has started to be erratic on the motors as they pulse on and off instead of constant when required to do so.

My question is could I add a separate esc and receiver to run the boat instead of using the supplied items on the boat.

The motors are connected together with a very thin soldered wires connecting it to the intergrated esc/ receiver pcb .

The motors and pcb at the moment are powered by a nimh battery pack (5 cell AA).

Advice great fully welcomed.

Dave

[David Smith 52Participant @davidsmith52]

[Dave Cooper 6Participant @davecooper6]

Hi David and welcome to the forum.

I think I would start by finding out exactly what you've got and what you haven't…

You can do this by cutting out the radio link entirely and connecting the battery pack directly to the motor(s). Use a length of wire with 2 'croc' clips at each end. If you still have erratic running, then the problem is either with the pack or with the motors.

Assuming these check out OK, then it's a process of elimination I'm afraid. Check all connections and connectors especially those on the PCB. A hairline crack here can play havoc with the rest of the system ! Then work backwards through the radio : eg Is the rudder(s) also twitching ? Test the Tx to Rx out using a spare servo (from your aircraft collection maybe).

TIP: A low-cost multimeter set to read "Ohms" can help you trace connectivity and poor solder joints etc. (once you have one you'll never want to part with it !).

Good hunting,

Dave

[ashley needhamParticipant @ashleyneedham69188]

David. In answer to your question, yes, you could fit a separate Receiver and esc. BUT…is there a rudder on the boat or is control simply by differential motor control? If there is no rudder then either you would have to fit one and a servo to operate it, or use two esc and a mixer.

HOWEVER…it would pay you to check a few things first as Dave quite rightly suggests.

The wires on these things tend to be thin and the soldering can give trouble.

Ashley

[Charles OatesParticipant @charlesoates31738]

One common problem leading to pulsing drive motors is the battery. As the motors start the voltage drops, the ESC s cut for a moment then come back as the battery recovers a bit. That said, it's certainly not the only possible cause, but it's an easy one to check. Does the fault only occur when the boat is in the water, but is fine on the bench? If so, check the battery with a meter, and the boat in the water. An AA pack driving the motors won't have much capacity or a high c rating so I would check that first.

Charles.

[David Smith 52Participant @davidsmith52]

Thanks for the replies.

The battery packs are relatively new and we're fully charged using a overlander charger unit that I use for my aircraft batteries.

The fault occurs on the bench as well as in water. I disconnected tge supply to the motors and then tried the tug again. The small smoke pump in the boat run intermittent just like the motors so it seems to me it is either the pub board or the tx.

If I go along the route of a new esc snd receiver are there dedicated bost esc,s ?

Alfo as asked earlier there is a rudder servo which works perfectly its only the motors and smoke pump that play up.

[Ray Wood 3Participant @raywood3]

Hi Dave,

Does your tug have a conventional receiver you can plug a speed controller into ? many of the RTR boats have a PC boards you mentioned to do all the clever stuff are directly wired, If so I would suggest you are snookered without a new radio !

The twin 280 size brushed motors would run fine from an Mtronics 15amp speed controller.

This tug is also marketed under the name Southampton and there are many conversions and pictures on Youtube to reference. The smaller than usual battery capacity is I imagine down the the weight of the plastic used in the superstructure, the video clips show the model rolling around quite a lot.

Regards Ray

Edited By Ray Wood 2 on 08/01/2022 12:04:06

[Dave Cooper 6Participant @davecooper6]

It would seem that the smoke pump and motor ESC(s) are driven from the same signal. The fault could lie with the Tx throttle stick(s), or, with the Rx /ESC end.

There are 'dedicated' boat ESC's – be careful to choose according to the type of motors you have eg."brushed" or, "brushless".

If brushed (2 contacts), do the direct pack-to-motor test first. If brushless (3 wires), you'll need a test Rx and ESC set-up. Is there a replacement PCB available for your boat ? This may turn out to be the cheapest fix…

Long thin wires between the pack and the rest of the system have many disadvantages : they can cause voltage drop, act as an aerial, usually have fragile soldering etc. etc. You could try replacing these with something better ie shorter and thicker.

If you could post a photo or, two, of the boat's interior that might help pin-point any other areas to investigate.

Dave

[David Smith 52Participant @davidsmith52]

I have now tested the motors by directly connecting the battery to them. They work perfectly , as suspected the fault lies with either the pcb/esc or the tx. I have ordered a boat esc and will use that with a spare Spektrum rx and tx.

Will report back if all is well once fitted and tested.

Dave

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