Giving Up the Gas

[CaddmannQ]

I finally decided that I want to fish at Lakes where they do not allow jet skis, ski boats, outboard motors, or noisy people of any sort.

So my 1969 Evinrude is going the way of the Dodo.


I've got a couple of 55 pound thrust electric motors, and coupled with my 40 pound thrust Minn Kota, I should be able to navigate the calm Waters that I intend to fish.

My neighbor Dave gave me these Navigator trolling motors, plus their brackets, controllers and wiring, 15 years ago. I am finally going to use them. Here's my first mock-up...

The brackets will have to change completely and the original controllers are wasteful of electricity and I'm just going to wire these motors up with direct switching.

Unfortunately electric motor controller circuits (even the modern ones) get very expensive when you're trying to control motors this large.

Fortunately, since these work, I can sell them for a good amount of money on eBay since you cannot buy them anymore.

I can use my 40 pound thrust motor for fine speed control and front steering, and the rear Motors will be on or off & tied by a rudder to my remote steering stick.

So my next task is: I have to build a rudder. Then I will need some more batteries. Big ones. The boat will not get lighter, just quieter and more stable, since the weight will be distributed along the hull instead of mostly at the stern.

Also I will probably eventually switch the rear Motors with simple switches from 6 to 12 to 24 volts, so I can at least have some speed control on them. On the other hand, after my first fishing trip I may decide this is completely unnecessary.

 

[ripjack13]

 

[John A.]

I don't think I've ever seen that done before. It's not a bad idea though.

I have one of the minn kota with a foot controller on my bass boat.

 

[MikeD]

I think I would try to use that to replace the lower unit on an old outboard. that way you still have all the steering, trim, etc you have with the outboard.

I like the concept. I think I have actually seen something similar somewhere but it's not coming to mind at the moment.

 

[CaddmannQ]

Well I considered that, but I have two Motors and I don't want this business to be any heavier than it absolutely needs to be so it will probably end up being a fairly light duty business or plastic and thin wall conduit.

I'm dumping all this stock bracketry, because it is heavy & just looks like excess hydrodynamic drag.

 

[MikeD]

If you took std motor and stripped the motor itself out as well as the drive shaft, that would reduce the weight a lot. You might them be able to run the power cables up through the unit as well.

 

[CaddmannQ]

I considered that, as my "shell" would be strong enough.

But, these motors both rotate in the same direction, so for best performance I should put them as far apart as practical.

The stock brackets don't get them that far apart, so I still have to do something fancy as far as mounting the motors.

If I can get matching left and right hand propellers, I could just switch the polarity on one motor, and then they could be close; but as far as I can tell they are unavailable.

 

[CaddmannQ]

Well I'm going to do a modified version of my initial design concept and for now I'm going to ignore the fact that I don't have a left hand propeller.

I have a feeling that if one is not available anywhere and so far it's not I might have to resort to 3D desktop Manufacturing.

Also based on my recent studies about propellers I'm thinking that the blades on these are not large enough. Running two of them on my little boat they will be rather unladen with the stock propellers. I will probably get better top speed with larger and more aggressive propellers.


Here's a crappy picture where I'm mocking up the theoretical position of my left motor. I'm going to try and put them far enough they won't interfere with each other's wake.

 

[Djcala]

Lord help Caddman. We gotta get you a new hobby and some Long John Silver fish coupons before your brain explodes.

 

[CaddmannQ]

I decided to forgo the remote steering and just use an ordinary tiller, which will shave 12 lbs off.

This mock-up i's all lashed up and clamped together & looks strange because I haven't trimmed any of the tubes yet, & the pivot setup is still held together with clamps.

But I have both motors hung now.

 

[CaddmannQ]

Lord help Caddman. We gotta get you a new hobby and some Long John Silver fish coupons before your brain explodes.

This is what happens when engineers retire and get to design stuff for themselves. There's no budget, there's no deadlines, there's nobody looking over your shoulder asking when it's going to be done or why you're doing it that way.

It's what I was wishing my job was like for the past 45 years.

 

[Djcala]

This is what happens when engineers retire and get to design stuff for themselves. There's no budget, there's no deadlines, there's nobody looking over your shoulder asking when it's going to be done or why you're doing it that way.

It's what I was wishing my job was like for the past 45 years.

Oh i get it im retired myself and get engrossed in my projects enjoying the autonomy to do things my way and my timeline. Freedom is an amazing thing. Keep up the good work.

 

[nitesite]

Put a Lycoming engine and a cage+propeller airboat assembly on your boat.

 

[CaddmannQ]

I fish deep water lakes; but ironically, if you ran an airboat up there you would quickly be in very deep shit.

Besides I don't want to scare the fish.

If I add any other propulsion to the boat than these electric motors it will be a sail.

 

[nitesite]

I only said that as a joke.

 

[CaddmannQ]

That never stopped me from taking someone seriously before!

 

[CaddmannQ]

The critical tiller pivot assembly is nearly complete,


...and I have removed the old wood, patched with epoxy, and getting ready to sand and paint.


What Engineers do with the old paper...

 

[CaddmannQ]

After dark Boat Works continues.

The transom plate is just thin aluminum, brush finished and painted clear with 8 stainless washer head neoprene seal screws. It's set in adhesive/sealant left over from work on the house.

The actual motor mount is tempered 3/8 stainless with 3/8 stainless bolts, rubber mounted. The tempered stainless was a bear to drill but I got it for free.


I used neoprene rubber bushings to space it off from the hull, seal the holes, and allow me to adjust the trim by simply moving the spacers around.

I won't be set up to adjust trim on the fly yet. With this little horsepower it's just not going to help IMO. But I do want to be able to experiment in order to set the best static trim.

Also there's still some clamp plates and ropes and shims, as I am still mocking up the motor stanchions.

So it's still not possible to tell what it's really going to look like when I'm done, but it's getting there.

 

[CaddmannQ]

Well it's been 24 days and I am still working on the boat everyday and probably 12 to 14 hours. You'd think that it would be a real show boat by now, but there are things you do over and over and over when you are prototyping. Also since the main propulsion is composed of hand-me-downs leftovers gimmies and backyard junk, the assembly procedures are often cumbersome difficult and time-consuming, and I'm working by myself.

But I have what I think is a reasonably sturdy propulsion assembly, 4 brand new batteries two new switches a bunch of new cables and terminals that I made up myself. So far I have about $500 into that part.

I have another $500 in 2 new seats, plus varnish, wood and stainless steel hardware to construct the two new decks, seat mounts, and new covers for the mid storage bins (which have now become the battery boxes for the forward motor.) There's at least another $100 in miscellaneous things like rope and solder and heat shrink tubing.

Anyhow the motors are wired up, they run, & I've done a wet test in some water-filled storage bins on my driveway. I think we're working with about 3 horsepower here. It's going to be veeeery slow compared to the old 40 horse gas motor, but that's okay I'm retired and I'm ready to do slow.

Since the new OS update to my Android phone I'm having a hard time making photographs small enough to upload on this site. They changed the camera resolutions which are available, and creating a one megabyte photograph has become a real pain. Anyhow I'll try to post some photographs this morning.

Here you can see the rear seats, the tiller, the plywood rear deck which also holds down the main battery pack, my green tool tray and my temporary plastic battery cover arrangement.

A word of advice: never do coxcombing with camouflage rope. It looks terrible. It just looks like a bunch of random knots on the tiller.

You can also see that the panel wiring it still not finished.


This is the business end of the tiller.
There are a few pieces of paracord to keep things from jiggling on the highway. This Arrangement is flexible on purpose. If I hit something with the motors, they will kick up out of the water, and if it doesn't, the tubing will bend rather than tear off the boat and rip a hole in my hull.

I am supposed to take it out with my shooting buddy Bobby and go fishing tomorrow. We've been out in this boat a dozen times but never on electric power only, except for our last trip and which we relied on the 40 pound thrust motor only. This is okay for six hours of trolling on two batteries, but not fast enough to get you anywhere.

The added hundred ten pounds of thrust will hopefully improve that situation.

 

[CaddmannQ]

I took the modified boat out for the first time today and I was really impressed with the way it ran. It was easy to handle and had enough power to do what it needs to do.

One of these motors has more wear on it than the other one, and I want to go through and rebuild both of them. New bearings and brushes seals and gaskets, and a lot of patience.

I was afraid that the boat was going to crab track a lot because of the Dual right hand propellers, but what really made it crab track is one motor is slightly more powerful than the other.

One of them is a bit more noisy as it has more wear on it.

Even so the effect was moderate and certainly did not make the boat hard to control but it will certainly be a little faster once everything is square.

My neighbor gave me these trolling motors nearly 15 years ago, and this project has been in the back of my mind since then. So it was an amazing thing to actually see it happen after all this time, and to have it work out as well as it did.

Since l don't have a speedometer, I don't know how fast we were going, but whatever it was it was fast enough for us to make a small wake.