Electronic speed control for trolling motor DIY

Thread starter #1
I have a Newport 46 lb trolling motor I run on lakes with my NuCanoe F12 'yak. It has 5 forward speeds and 3 reverse. The speed is controlled internally by a "speed coil" which is just a tapped wirewound resistor, so any speed under full is wasting energy as heat. Also the slow speed isn't really slow enough for trolling. I'm not big into trolling, but when moving from spot to spot I throw out a shad rap and sometimes catch one.

I bought a 60 Amp PWM speed control on evilbay, a Chinese circuit, for $13. The circuit is a rather amateurish design using a cheap timer chip (555) with relays to control direction (instead of a full "H-bridge" for ye geeks), but it works. I disconnected the switch inside the TM head and straight wired the motor red & black to the power red & black (why don't they use white and gold haha) with 2 red wire nuts. The handle is for steering only now. I use Anderson Powerpole 45A connectors for hookup.

I bought a cheap ($6) waterproof plastic box at WM (a Pelican knock-off in camping section) The module is inside with the speed knob and direction switch mounted in the lid, with #10 AWG wires in (from battery) and out (to trolling motor). 40A circuit breaker at the battery end. I'm using a 35 AH deep cycle wheelchair/scooter battery, which is just enough to run around a small lake like HG Lathem (I have a huge marine deep cycle size 31 Duracell platimum, but that brute weighs more than the kayak). Eventually I plan to get a lithium ion battery, but they are $$$.

Now I can control speed perfectly without wasting energy. Minn-Kota used to sell a version of this called a "maximizer" but they are no longer made. Eventually I will make a more permanent version with a remote control in a smaller box you can mount to the track.

I am happy to report it works quite well, and I only have about $35 in it, not counting the wire. I was going to upload a youtube on how to do it, but since they are censoring the right, that is not going to happen. I will, however, help any fellow fishermen/fisherwomen who want to make one, just send a PM.
box1.jpg box2.jpg
 
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Thread starter #3
NuCanoe has a squared-off transom. I just clamp it on the usual way, with a piece of cutting board as reinforcement. I'll take a pic when I get to the lake tomorrow.
 

Bream Pole

Senior Member
I did the same thing for my kayak and also my 12 ft and 10 ft jon boats several years ago. Works like a charm. I use a 25 lb bass pro agm battery in the kayak and regular trolling motor batteries in the jon boats. Never have I run out of power, but not paying much attention to how long I ran it so really can't supply you with information on hrs can run on the battery. Also have an 18ah sealed lead acid battery which is lighter, but haven't tried it.

I took a piece of square aluminum tubing and bolted a piece of treated lumber to one end to clamp the motor on. The tubing has holes in it as does the kayak and I bolt the tubing across the kayak behind me whenever I am going to use the trolling motor. I actually use a very light 10 lb thrust vintage minn kota trolling motor for the Kayak. I also shortened the shaft on it. Motor may be 12 inches from the rear of the kayak when mounted. Works well.
 
I have a Newport 46 lb trolling motor I run on lakes with my NuCanoe F12 'yak. It has 5 forward speeds and 3 reverse. The speed is controlled internally by a "speed coil" which is just a tapped wirewound resistor, so any speed under full is wasting energy as heat. Also the slow speed isn't really slow enough for trolling. I'm not big into trolling, but when moving from spot to spot I throw out a shad rap and sometimes catch one.

I bought a 60 Amp PWM speed control on evilbay, a Chinese circuit, for $13. The circuit is a rather amateurish design using a cheap timer chip (555) with relays to control direction (instead of a full "H-bridge" for ye geeks), but it works. I disconnected the switch inside the TM head and straight wired the motor red & black to the power red & black (why don't they use white and gold haha) with 2 red wire nuts. The handle is for steering only now. I use Anderson Powerpole 45A connectors for hookup.

I bought a cheap ($6) waterproof plastic box at WM (a Pelican knock-off in camping section) The module is inside with the speed knob and direction switch mounted in the lid, with #10 AWG wires in (from battery) and out (to trolling motor). 40A circuit breaker at the battery end. I'm using a 35 AH deep cycle wheelchair/scooter battery, which is just enough to run around a small lake like HG Lathem (I have a huge marine deep cycle size 31 Duracell platimum, but that brute weighs more than the kayak). Eventually I plan to get a lithium ion battery, but they are $$$.

Now I can control speed perfectly without wasting energy. Minn-Kota used to sell a version of this called a "maximizer" but they are no longer made. Eventually I will make a more permanent version with a remote control in a smaller box you can mount to the track.

I am happy to report it works quite well, and I only have about $35 in it, not counting the wire. I was going to upload a youtube on how to do it, but since they are censoring the right, that is not going to happen. I will, however, help any fellow fishermen/fisherwomen who want to make one, just send a PM.
View attachment 942172 View attachment 942173
Will this work with a 24 volt motor? I have an old motorguide 78 pound speed coil motor on my small boat and I want to slow it down for pulling live bait.
 
Thread starter #7
The module I used was (claimed) rated for up to 75V, so it should work fine at 24V. I don't notice any heat at all. I've been using the heck out of it, too. So far, so good.
 

Steve762us

Senior Member
I bought a 60 Amp PWM speed control on evilbay, a Chinese circuit, for $13.

I bought a cheap ($6) waterproof plastic box at WM (a Pelican knock-off in camping section) The module is inside with the speed knob and direction switch mounted in the lid, with #10 AWG wires in (from battery) and out (to trolling motor).
Beautiful Job!

I've been watching the PWM speed control modules go up in ampacity, and down
in price--but wondered about the ventilation for cooling. If it's working in that
dry box, that's fantastic.

Is the rocker switch for reversing prop rotation/motor direction?

Edit: just re-read, yup--reversing switch!
 
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Thread starter #9
No heat issues, even in August riding around wide open. I really like the ability to dial speed just right for trolling. The cheap-o switch failed on me. I cleaned it and it’s working fine, but gonna order a decent replacement from mouser.com.
 
I've rebuilt the footswitch for a 40# MinnKota more times than I can remember, and replaced the steering motor control board; first with two double pole/double throw relays, and later with a $3 Chinesium control board--similar to yours, but only designed to handle a few amps...enough for the steering motor.

Since the original footswitch circuitry gave up, prop motor's been all-or-nothing, for speed. I might just go for your set up, since it can be sealed (except for the speed pot)...and it can actually handle the amps! Chinese amps, like Chinese lumens, sometimes seem a tad inflated!

BTW, a toggle switch with rubber boot will last longer than that rocker. I've got half a dozen toggle switches with boots on my center console---for at least 5 years, and none have given up yet, and I run in salt. These are cheap-o toggles, too!
 
Creek boat uses a control like that with their trolling motor setup. Been good setup for me so far.
 
I used one of the PWMs on amazon to replace the guts on my creekboat after a rough night that cost us the trolling motor etc. After I did it I set up my gheenoe just like my creek boat with the pedal steering and the pwm. I love it.
 

blocky

Senior Member
Rambling wreck, is this unit suitable for the controller? 10-55V 60A 3KW Reversible DC Motor Speed Controller PWM Control Digital Display

Found this on ebay
 
Thread starter #14
I've had some PMs for more details. I'm not gonna spend all night typing a step-by-step tutorial, but if you have specific questions along the way I'll be glad to help. Here's some more details:

The PWM module I used is this one from ebay: Link

The waterproof box I used is from Walmart, bought at the store : Link I cut holes in the top for the switch and the pot as you can see in the pic. Make sure the switch clears when you shut the lid before cutting a hole - where I put mine is kinda tight. I used a mototool cut-off wheel for the rectangular hole, just go slow and wear eye protection in case a piece flies off. The switch just snaps in, but I used some Goop around the hole to seal it to the case. (I got coffee in the switch fishing, and had to replace it later when it corroded inside, or something, and quit working right. I had to paddle! Almost forgot how, and wind was blowing, too. Jameco has the same size/type switches for like $2.50, and better quality).

I used #8 gauge copper red/black zipcord for the power in (from battery&breaker) and out (to motor power leads). You have to kind of part the strands down the middle to get it under the screw terminals on the module. I ran the leads thru holes drilled thru the box, and sealed with marine Goop or you can use RTV. Or get fancy and use a watertight gland nut - expensive. I didn't use the display, and just unplugged it from the module. Its useless to me and just wastes power.

I used Anderson Power poles for connectors. You can crimp or solder them. Get the kind that supports the max current draw, in Amps, of your motor, that fits the wire you are using. I got the ones for #8 wire, but #10 was probably fine. I over-design. Sue me. :cool:

Speaking of motors, I straight wired the power leads in the motor head to the internal (heavy gauge) hot and ground leads that go down the shaft to the motor with wire nuts, and disconnected the stock controls completely. I only use the handle/tiller for steering. THIS WILL VOID YOUR WARRANTY. If you don't want to do this, you will have to just leave the motor on forward high/full throttle all the time and control speed with the box. That's why you made it, remember? ;)

Make sure you have a breaker at the battery! Never hook it up wrong! Check your work - twice - before powering up! Once it zaps - the module is toast. Don't let the magic smoke out - it doesn't go back in. LOL

I mounted the module (I threw out the aluminum shield or you can keep it) using 3M peel and stick PCB stand-offs I had lying around my lab. You will have to find something similar, from Frys maybe, or just DIY some sort of way to attach the module to the case.

Good luck. (y)

Joe aka RW :geek:

PS: I didn't paddle that time, I lied. I opened it up and cut & twisted the two wires from the switch for "forward" and proceeded merrily on my way. I'm most always merry, 'cept when I just lost a good fish, or broke off my spybait on a snag. :mad:
 
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Thread starter #15
Rambling wreck, is this unit suitable for the controller? 10-55V 60A 3KW Reversible DC Motor Speed Controller PWM Control Digital Display
Found this on ebay
No link in your post, so I don't know. I posted a link to the one I used above. There are many that would work. Hasn't blown up yet, and I use it a lot.
 
Hello...I use a 25 lb bass pro agm battery in the kayak and regular trolling motor batteries in the jon boats. Never have I run out of power, but not paying much attention to how long I ran it so really can't supply you with information on hrs can run on the battery.

complete pcb
 
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I want to make sure that what I have done will work. I have a Minn Kota 95 W from 1985-1986. I first removed the 5-speed switch. All the associated wiring was either removed or the connectors were cut off and the ends of the wires were wrapped. I connected the + and - battery power leads to the 2 "power" in connections on the pwm. I then connected the red and black wires that come from the motor lower unit to the + and - "motor" connections on the pwm. I mounted the pwm FWD-OFF-REV switch and the led readout where the original trolling motor switch was located. I was able to connect the pwm pot to the trolling motor telescoping handle so that the modulating speed is controlled in the same way as the original 5-speed switch. Before I "power up" I want your feedback on the likelihood I've got it right. Thanks!
 
Hopefully Ramblin' Wreck will roll in, but double-check you have correct polarities on
your power-in terminals, particularly. Won't hurt checking actual wires with meter to
insure 'red' is actually positive, and 'black', negative. Some pwm boards are not
protected from reverse-polarity hook up, and will let the smoke out.

If you find the motor seems to run 'backwards', reverse the motor connections.
 
Thread starter #19
We have no way of knowing if you've got it right, other than to say that "sounds right". Double-check your polarities, especially Power In +/-, and go for it. Also use a breaker or fuse of appropriate amperage on the positive battery lead.

Part of the thrill of electronics projects is the first power up.
 
Thanks Steve and Ramblin' Wreck for your feedback and suggestions! As soon as I add the suggested beaker I will take the plunge and hope that everything floats.
 
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