With a friend, I recently used a trolling motor with a canoe. The motor was mounted on a bracket off to the side of the stern, and the battery was amidships. The "angle of attack" of the canoe was off a little bit at times but, otherwise this setup worked fine. What occurs to me now is that it might not work as well without someone else in the front. I'm trying to conceive of an ideal solution. I don't like the idea of using a canoe w/ a transom, since it seems that this would compromise the boat as a paddling craft.
I have the following idea for solo use w/ a trolling motor, and maybe a small outboard some day:
I am thinking of sitting backwards in the front seat (since I'd be closer to amidship, and also so I'd have more room behind the seat than I would otherwise. So far, there's nothing new here. Then, I would have a large triangle of plywood, aluminum, etc., mounted under the gunwales behind me. This would be braced by cross-thwarts going over the gunwales, and bolted to the triangular piece underneath. Then, a member would extend directly behind me, mounted to the triangle, and terminate with a flat mounting surface. It would be on this surface that I would mount the motor. An engineer friend says that it's a bad idea in that it would introduce too much "moment" (force over distance). If the materials were strong enough (such as welded aluminum) I can't see this as being a problem. The pieces would be strong relative to each other, and I'd have a large mounting area for the triangle against the gunwales.
This would solve several problems: I wouldn't have weight listing off to the side, I could paddle to make small adjustments to the canoe when fishing without having the motor in the way, there would (presumably) be less perturbance to the craft as the motor is hoisted out of the water, and the motor would be in-line with the canoe.
Any thoughts on this? Thanks.
It sounds do-able
As far as the structure that reaches back over the stern being strong enough, it’s not the material as much as the shape of the structure. You could make it more than strong enough if it were essentially a “box” made from quarter-inch plywood, but if you can weld an aluminum framework, that would be easier, especially since that would make it easier to surround the higher part of the boat’s stem, making the whole “bridge structure” a lot lower (which in turn would reduce the amount of strength needed).
What occurs to me is that someone ought to invent a dual electric motor setup for canoes, using two smaller motors having the same output as a single normal motor. With one motor on each side, interlocked in similar manner as the front wheels of your car, you’d eliminate the problem of offset weight and thrust. There’d be more overall weight per unit of power or thrust than with a single motor though.
One other idea for your situation would be a foot-controlled motor mounted as far forward as possible, so the motor pulls the boat. On other small boats, this is a far more stable setup, as far as any tendency to crab or wander, than a motor that pushes off-center from the rear. You’d save weight and complexity, and have better overall trim too.
thanks for the reply
I’ve thought about putting a motor in the front. It seems simple enough and superior to have an electric motor up front rather than in the back. I am currently installing a “pulse width modulator” in a box midway between the battery and motor. The box has a knob on it that I can use to turn the motor on/off, and adjust the speed. So far, as it’s set up, it won’t go in reverse. This is fine though, I doubt that I’d need to go in reverse. As for steering, it can be done easily enough with a paddle, at least with the motor mounted in the back. I’d assume that in the front, paddle steering should work well also.
I’ve considered the “dual motor” solution. The main disadvantage is that it doesn’t solve problems associated with a gas outboard. It would be GREAT if one of the large companies would make a good 10 lb gas outboard.
As for getting around the stem w/ aluminum vs wood, I’m not sure that I know what you mean. I’m assuming that you are referring to going over the stem, rather than around it on both sides.
As for aluminum, I don’t really know what the parameters would be for strenth, weight, and shape. The easiest solution would be to have the “arm” be made of a bent flat bar, possibly reinforced at a bend. Another solution would be to use aluminum tube, as is seen in bicycles. This would be far superior structurally, but a pain from a design standpoint.
Dual tubes going around the stem might be the best idea. There might even be pre-made angled aluminum couplings for such a purpose.
The only real issue I have at this point is the size of the aluminum piece under the gunwales. A greater distance b/t the front and back of the triangle would mean better force distribution. A smaller triangle would mean being able to mount it on behind the rear seat for tandem purposes. I don’t know if there’s an easy solution. Maybe two triangles would be good, using either as appropriate.
is it worth it?
I’ve been revisiting the idea of this type of mount, which would keep thrust in line with the center line of the canoe. I wonder how much stability this would add. In an ideally balanced canoe, the weight would be evenly distributed, but this would change as soon as the boat rocks to one side or the other. This would be far more pronounced in a double-ended canoe than in a boat with a wide stern (presumably with a transom).
Also, the nature of the canoe is to be long and thin. Turning would cause the craft to rock much more than a wider boat, regardless of whether the motor is mounted on the back or the side.
So, I wonder if a back mount would give me any advantages at all. Any thoughts?
Having Used Trolling Motors And…
...outboards on John boats and on a square stern canoe, IMHO the "Side" mount is easier on the back to me. It is a bit awkward until you get used to it, but I like it better. Not sure I've seen any other kind of mount? I can't "Picture" the mount you're describing?
Also, an old Paddling.net friend whom has gone to his "Reward," NT taught me a nice trick about trolling motors. He got extra wiring and spliced it on to make an extra long wire harness. That way you could put your trolling motor as far in front of you as you needed to to help "Trim."
That said, I'd be a bit dubious about a trolling motor on any solo canoes. Take care!
I can’t “Picture” the mount you’re descr
I tried adding an ASCII drawing, but it didn't work. Essentially, the motor will be hung directly off the back of the canoe.
The motor will be positioned, then not touched again. I will have the ability to raise/lower it, but that's not really part of the question. Speed will be controlled with a control box (with a dead man switch) from anywhere in the canoe, which I've already made. The battery will be positioned where it will trim the canoe the best. Steering will be done with a paddle.
The motor has three parts: the head, the shaft, and the sponson at the bottom that contains the motor and propeller. The sponson is by far the heaviest part of the whole assembly, and will be close to, if not below, the bottom of the canoe.
I currently have the motor hanging off to one side. Here, I make periodic adjustments to position it left or right. I won't "need" to do this if the motor is at the back. The whole point of putting the motor on the back is to have a setup that is more stable than having a motor hanging off the side. However, I don't know if this would add any appreciable stability.
Edit: Though the mounting system will be different, the position of the motor sponson in relation to the hull will be similar to what is seen with these motors and kayaks:
http://www.kayaktrollingmotor.com/
Hmmm…
…looks like it would work even on small boats?
that’s the million dollar question
I wish I knew and that’s what I’m trying to find out. If I can get a trolling motor to work with a solo canoe, that would give me the best of both worlds:
a fishing canoe that can range far for use with a trolling motor, as well as a canoe that would handle well with a paddle.
Torqeedo
Check out the Torqeedo ultralight, for kayaks (and canoes, I imagine). It has an offset mounting that positions the propeller pod on the central axis of the boat (a sponson is something else, BTW).
http://www.torqeedo.com/en/products/outboards/ultralight
It’s expensive and you sound like you’re almost done, but you can use it for ideas. Re your engineer friend, we’re talking only a few pounds of thrust, so the forces and moments generated will be low. As long as the propeller is centered and the attachment to the canoe is symmetrical, the thrust will be in line.
side mount vs transom mount
i’ve been using a side mount with a 45 lb thrust for 3 months now on a lake in the adirondacks… lots of lilly pads and milfoil… it would be very difficult to clear the prop of weeds with a transom mount…
i also put outriggers on same and can stand and fish while running motor and working edge of weed beds
i also put a stand-up bar in the middle of the canoe and can stand up and cruise at full speed
good point
I'm glad that you mentioned that. This changes my thinking on the matter. If anything, I think that this would only work in open water then.
The bow
seems a rather likely place for the motor to come into contact with an obstruction during forward locomotion. I’m not certain that I like that idea very much, but I can see where it would make for easier mounting.
A stern mount rig is probably the most manageable system. One could possibly mount 2 props off a single engine and deploy one prop on either side of the craft if one was looking for good balance. Not sure how workable that is as a concept, but it has been done on other hulls.
Rick