# Electronic speed control for trolling motor DIY



## RamblinWreck (Sep 5, 2018)

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.


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## j_seph (Sep 5, 2018)

Any pictures as to how you attached trolling motor to yak @RamblinWreck


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## RamblinWreck (Sep 5, 2018)

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.


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## Bream Pole (Sep 7, 2018)

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.


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## RamblinWreck (Oct 15, 2018)

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.


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## Steve762us (Oct 29, 2018)

RamblinWreck said:


> 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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## RamblinWreck (Oct 29, 2018)

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.


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## Steve762us (Oct 29, 2018)

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!


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## deerehauler (Nov 12, 2018)

Creek boat uses a control like that with their trolling motor setup. Been good setup for me so far.


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## warefishin (Nov 25, 2018)

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.


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## blocky (Dec 2, 2018)

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


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## RamblinWreck (Dec 2, 2018)

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. 

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. 

Joe aka RW 

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.


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## RamblinWreck (Dec 2, 2018)

blocky said:


> 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.


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## TimiSchor (Dec 20, 2018)

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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## Yendor (Jan 23, 2019)

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!


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## Steve762us (Jan 23, 2019)

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.


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## RamblinWreck (Jan 24, 2019)

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.


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## Yendor (Jan 24, 2019)

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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## RamblinWreck (Mar 12, 2019)

The module comes with a SPDT switch to reverse direction: FWD-OFF-REV. You don't want a switch on the main power leads because the back-EMF of the motor will quickly ruin the switch contacts from arcing. The motor will be fine but the switch will wear quickly.


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## RamblinWreck (Mar 12, 2019)

Not to mention a DPDT switch that can handle 50A will be an expensive monster!


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## RamblinWreck (Mar 12, 2019)

In general, you cannot reverse the input power to the module - that may fry it. In any case, the input power is the same as the motor power, so there is no advantage.


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## Steve762us (Mar 12, 2019)

The upper diagram bypasses the speed control entirely
in one position.

The lower diagram would work, *but* for price of switch
that could handle the amperage, you'd be better off
just getting another $15 module that's designed/comes 
with a reversing switch---which will be an inexpensively
replaceable switch, when it inevitably croaks from salt
exposure.


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## RamblinWreck (Mar 12, 2019)

Ya know, if you throttled all the way down or turned off before switching, which is not really a terribly restrictive requirement, you wouldn't have the arcing, but you still need a switch/relay that can handle the DC motor current, not to mention have lugs that can accept #10 AWG wire. I don't have time to look at that relay, as I am off to Oconee in the early AM, but if you think it will work, go for it. As long as the end result performs, who's to say what's right or wrong?


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## RamblinWreck (Mar 18, 2019)

Yes I are.


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## NormO (Sep 18, 2019)

RamblinWreck, your posts and details on the components and usage are terrific.  While waiting I have a question and a couple tips? to share.

*Question*:  I don't have the controller yet but am wondering if it is possible to separate the pot from the other components of the controller?  I'll be using it in a Gheenoe where I will be moving around more than in my Tarpon 10.  I envision a 1)  pot and another on-off switch in a small container located nearby the operator that is 2) separated by a nice length of coiled small gauge wiring from 3) the remainder of the controller with its heavier wiring which would be housed in a second container located in a safe place near the battery.  

*Tip? * A friend has a diy controller on his Outback.  He grew tired of having to readjust the pot after turning the pot to off when he wanted to coast and then back on when he wanted to resume.  He modified it by installed a separate on-off switch in the circuit which turned the TM off.  When he wanted to resume he merely turned this switch back on.  Since he didn't touch the pot the TM returned to its previous setting.  He said this made it much easier to maintain a desired trolling speed. 

*Tip? 2*  I bought a DC 6.5-100V, 0-100 amp LCD digital multimeter that displays volts, amps, watts and watt-hours.  Mine carried the Drok label but Mictuning and others sell the same thing on Amazon.  It  costs $17 and they are China's best small hard to read delicate instruments.  I'm using it to determine the energy used by my TM at various speed settings.  I ran tests in the water and recorded data for speed settings 1, 3, and 5.  I then transferred the data to a simple a simple spreadsheet where I can input the expected minutes of operation at various speed settings for the lakes I fish and it would calculate the watt hours of energy used.    This proved helpful to get a sense of the battery capacity needed. 

As a decades ago electronic project enthusiast I got a hardy chuckle out of your comment "Part of the thrill of electronics projects is the first power up."  Soo true.


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## RamblinWreck (Sep 18, 2019)

Comments:
1) The pot is already on a short ribbon cable, so you can extend it and remote mount it as you wish. You don't have to use the on/off switch in the pot, you can move those 2 wires to a separate switch, or just use the fwd/off/rev switch. Since I have a chartplotter/FF on the yak, I use the GPS to show the speed for trolling, usually 0.8 MPH when long-lining jigs for crappie.

2) It is not very accurate to try to estimate battery charge by the voltage. I just fish and find out by doing it how long it lasts. My new Ionic lithium battery is 50 Ah, runs my trolling motor 2 days without a charge, and has a Bluetooth phone app that shows you all the data: voltage, current, temp, and remaining charge % on my iPhone. Plus it only weighs 15 lbs, compared to 45 lbs for a 35 Ah AGM deep cycle mobility batt I was using, that would barely make it thru one day. Expensive but worth it IMO.


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## ByronDonald (Feb 25, 2020)

Hi....I guess I can see if one keeps varying the speed (or DC current) may be tough on TM. So, is that why TM was only designed to keep at 5 speeds instead of variable to ensure the TM don't breakdown? Why is the new TM all put emphasis on having the digital maximizer aka. variable speed?

order pcb


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## weagle (Feb 25, 2020)

Cool.  I need to do this to my Kayak trolling motor.  I undid the head on the motor and just extended the wires back to a box by my seat.  Somehow that caused it to go from 5 forward and 3 reverse to 2 forward and 1 reverse.


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## RamblinWreck (Feb 25, 2020)

There are two low-Ohm speed coils that act as resistors, and the (twist) rotary wafer switch connects them and the motor leads in various ways to create the 5F/3R speeds. It is very cheaply constructed and probably got out of "time" in the move, or something. With the controller, you only use the 2 wires that go to the motor, and tape off the rest.


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## RamblinWreck (Aug 13, 2020)

*UPDATE Aug 13, 2020 :*

Well, the trolling motor stopped working yesterday for some reason. Of course I was way down Lathem by the creek and had to paddle all the way back, while a thunderstorm was threatening.

Today I tested the speed control and all was as it should be. The motor Ohm reading was intermittent, so I took apart the motor (Newport NV series 46 lb thrust). The entire motor and commutator area was full of water. The main bearing was corroded along with everything else, and one brush/spring was damaged. So the motor is toast. It lasted barely a month out of the 2-year warranty. It was used heavily, but not abused.



Not sure if it is even worth the trouble to try and rebuild it. The good news is this is a cheap motor (@ $180); the bad news is it only lasted 2 years.


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## RamblinWreck (Aug 13, 2020)

Stay tuned. Newport had me fill out a warranty claim, so we'll see what they can do. It is obvious from the amount of corrosion that this has been an issue since before the warranty expired July 15, so they said to fill out a claim and attach pics. So we'll see how it goes. In the meantime I cleaned it up - The rotor Ohms out, and I think with a new brush assembly and some extra sealant I might be able to fix it, however, the commutator is pretty scarred up, so it would just eat up the brushes in a few months. Here's hoping NV makes it right.


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## dank1296 (Aug 13, 2020)

Thats not good. How was the fishing


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## RamblinWreck (Aug 13, 2020)

I might have caught a few.  Spotted some slab crappie holding on a tree at around 20 feet, and caught and released a bunch, including the 1.5 lb slab below.



When when the crappie bite died off, I went looking for bass. Used the UL rig with trout magnet, 2 lb test. It was FUN. They were in deep water suspended around 15-20 feet. This 2 lb spot gave me a fit.


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## RamblinWreck (Aug 14, 2020)

Kudos to Newport Vessels customer support! They approved my warranty claim and are sending me a new one! AWESOME

It helps to send decent pictures and full info on these kinda deals. 

I noticed the low-end MK Edge motors look exactly like the Newport. I bet they are from the same factory. I have a MK Terrova iPilot on my "big" boat, but for a kayak or jon, these Newports are hard to beat.


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## Steve762us (Aug 17, 2020)

Trolling motors aren't exactly "high tech".  

Just replaced end cap on my MK last year, after sleeve bearing started screeching.
Insides looked about same as your pic.  

Easy fix, but the cheap Chinesium _*brushless*_ trolling motors are darn tempting!


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## RamblinWreck (Aug 18, 2020)

I decided to rebuild the old one just for the heck of it and to learn to fix TMs, since NV told me I didn't need to send it back. I hate to throw out something that might be fixable, and a spare motor would be good to have around. Got some new brushes and seals on the way for not too much money, so I'll give it a try.

Brushless motors require a much more complicated control circuit to generate the drive phases, and while you don't get the arcing RF noise from the brushes, they still generate a lot of digital switching noise that could potentially interfere with sensitive sonars, if the noise is close to the operating sonar frequencie(s). The cost is keeping me away from trying one, and I'm trying to avoid buying Chinese goods - trading with the enemy, ya know.


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## RamblinWreck (Aug 26, 2020)

Ran my repaired motor this morning; had to replace brushes and seals. NV sent the wrong parts twice, but I finally got the old motor fixed. So far so good. The new motor is on it's way, and should be here Friday. 

The fish were definitely biting. I boated a dozen nice crappie, and a few small bass, cruising around testing the motor.


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## dank1296 (Aug 26, 2020)

Hey thats my favorite spot


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