wireless variable controller?

[vicgin]

Need a wireless variable speed control system for dual electric propulsion motors (24 v).
Can't use the "state of the art" integrated system stuff from Raymarine and the like.
I would like to seperate the speed and direction of each motor from one handheld remote.
Simply, that's all I need. Anyone help me with info?
Regards all,
Herbert

[jonr]

The radio controlled RC model guys do it all the time - only difference being that the motors are somewhat smaller. You also need two DC motor controllers.

[kroberts]

I would only be able to expand on what jonr said.

If you go that route, you need a 4 channel system. Practically speaking, I think that all 4-channel surface systems have very specific things in mind for the extra 2 channels. I've never used one, I prefer aircraft style dual sticks even on cars. There are some cars that need it, a rock crawler has a setup very similar to what you're talking about. It has a separate motor and steering for the front set and the back set. Both sticks are set up the same way, which makes it pretty easy. You have the front wheels on one stick and the back on another. Generally you program the transmitter so you can link the throttles and possibly the steering for easier going sometimes.

The AM and FM systems have laws in most countries which regulate RF energy that dictate that a surface radio only be used for surface, and an aircraft radio only be used for aircraft. You can ignore this if you stay away from other RC guys, the main point here is to prevent interference on a crowded field.

If you go to 2.4 ghz, which is a new band supporting several new technologies, you can pretty much do what you want as long as the equipment supports it.

I use Spektrum, which is one brand of spread spectrum signals on this band. Once you pick a technology/brand, you have to stick with it for both receiver and transmitter. Servos are mostly interchangeable. There are no crystals, your receiver binds directly to your transmitter and will ignore everyone else. In Spektrum, the hardware still dictates you either pick "air" or "surface" in that the transmitters/receivers which are designed for aircraft use one protocol and the surface equipment uses another.

That said, legally speaking as long as you get equipment that works together, you can do just about anything you want. The higher quality gear has dual receivers to prevent interference, and there are servos that might be adequate for real use turning a trolling motor. There are also gear reductions that are bolt-on to these servos. Most of the good servos can be set up to have the sensors on the final bell crank and that means you get a hugely strong servo in RC terms. Strong enough to have a more than 1/4 scale aircraft flying several hundred miles an hour, or a 30+ lbs RC car over extremely rough terrain. I've seen a big car like that almost totally balanced on one front wheel coming off a rock, and still able to lift the whole car by turning the steering wheel. That's with a standard high quality servo.

I'm not in any way saying that these things can throw your trolling motors around, only that it's worth further research.

What I would do is go out on your boat and find the combination of thrust and turning that takes the most turning force. Probably full throttle and some sort of high speed turn. If you can find out how much torque it takes and how much speed you need, you could find out if this idea will work for you.


Now for the bad news: Bring money. I can't imagine a more expensive way to do this. The transmitter will be $200 or so, with a receiver. The servos cost $150 each for the quality I'm talking about, you'll need 2. Motor controllers you might want to look at golf cart controllers plus some sort of circuit that will convert the receiver signal into whatever the golf controller wants; or maybe there's an RC controller that will directly handle a DC motor that current. Look for continuous capacity. No idea what that would cost.

[vicgin]

'preciate the replys guys.
Am intrigued with the golf cart controller. Hadn't thought of that.
Regards, Herbert

[kroberts]

The thing you have to watch out for is the input mechanism. Chances are, the golf cart won't take the same sort of signal and you'll need some sort of converter, which you may need to put together with a soldering iron from plans on the Internet.

Curtis makes controllers for just about anything from motor scooters all the way up to electric cars. You can buy them new, and they also make them for AC if you were interested in going there. A search engine is your friend here, you may have to hit a few sites to get more terms and then search from there.

I think there might also be a way to use a TV remote, since you'll always be line of sight. Only there you'll probably REALLY need the soldering iron.

Good luck and have fun.

[Pandoras box]

Do your trolling motors already have throttle controls on them if so then standard servos should be able to move the throttle controls? I assume that you will also need to control forward and reverse, if so you can use a system that works or like a ballpoint pen in that when the throttle is at zero and you move the stick a little further or move the trim it will push a ballpoint pen button and change the direction. Of course there are a hundred other options. If you go over to one of the model boat forums you can read about all sorts of different ideas will you have to do is scale them up to your needs.
This is all assuming that you are handy with tools and basic machinery.