Lightweight Bigwheel Kayak Trolley

by andrewwilson in Workshop > Metalworking

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Lightweight Bigwheel Kayak Trolley

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I am a recent convert to Kayaking.

I use to go sailing a lot, years ago, and many year prior to that as a teen. I wanted to get back into sailing, but, alas, money to tight too mention!
So, after seeing my Brother In Law's kayak, I thought this would be a great, simple, and cheap way to get back on the water. It is. It's not sailing, (though you can add sails to a kayak), it's different and no less fun.

Kayak's such as mine, Hybrid and Sit On Top, by their design, are not generally heavy, around 30 to 40 kg for one around 3 meters long. This makes them easy to carry, but once you add gear ie. Anchor Trolley (another Instructables coming), Anchor, Lights, Fishing Gear, your lunch!, it can get heavy. Carrying it over a distance can be a burden as well.

Why build my own Kayak Trolley?
Well besides the challenge, there were several criteria.

One.
It had to be cheap.
To get the features I wanted in a trolley, I would have to pay a premium price.
I wanted beach wheels. You can get small plastic trolleys for around $100 on sale if you are lucky, most are price in the $150 to $200 range. I also wanted it to be something I could easily build myself.

Two.
I wanted beach wheels, as the skinnier tyres offered on the cheap trolleys are more likely to sink in soft sand, making it harder to transport your kayak. To buy just beach wheels on their own is around $100 - $150 a pair!
My solution would need to be cheaper, along with the whole trolley design.
I will reveal how cheap over on the next page.

Three.
The design had to be simple, functional, and made with the least amount of bought parts I could get away with. I wished to use some of what I had lying around the shed and house.

Four.
I had to be able to build it with the tools I had on hand.
This Kayak Trolley could be built with nothing more than hand tools and hand held power tools. I used a welder in this project, but with a few mods, you could do it without one. Even the cutting could be done with hand tools, such as a hacksaw, and the slots cut, could be done with a drill bit and cold chisel.

Five.
Lastly, it had to be light, and as rust proof as I could make it. I knew I could not build it in all aluminium, or plastic, but most of it would be. I would end up using some steel parts, so they would have to be stainless steel, or painted/galvanised for protection from the elements.

This is a very simple build. Read on.

Wheel It Be Good? the Wheely Good Parts.

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I had an idea of what type of trolley I wished to build, before I got the parts.
I thought a simple 'H Frame' would give me the most solid build, with the most simplest design/build options. As I have a Hybrid Kayak, the back being inclosed like a Sit On Top, and the front open like a Sit In Kayak, I could use a Kayak Trolley that has poles, that go up through the kayak's body, scupper holes, holding the trolley onto the kayak, with the kakay sitting on top.

I do also own a Canoe, and with some removable addons, I could adapt this trolley to carry that as well.

As to the Wheels. To buy kayak trolley or cart wheels, that are 'beach wheels', I would end up paying a premium. Anywhere from $100 to $150 per pair as I wrote earlier.
I did not really want to use regular pneumatic wheels, like on a hand cart, as these could easily become bogged down in soft sand, though they do cost a reasonable $30 a pair, if you shop around.
I wanted, and needed wide wheels.

While I thought about what to do about this problem, I went to my local K-Mart to shop for some new shoes and fishing sinkers. When I was in the toy/bike/sports section (where they used to put the fishing gear, I looked down at a bottom shelf and saw, BIG FAT WHEELS!
Eureka!
I had found what I was looking for, by chance alone. With trepidation, I looked for a price sticker. $8. $8 each! Woah. The roof cracked open, the sun shone in, harps began to play.
I had found my wheels.
These were wide enough, big enough, and extra cheap. Forget $100 or more, each.

For a total of $16 AU, I got two wheels!

They whole project ending up costing me the equivalent of $48 in parts. This includes the bolts, metal plates, rivets, washers as well as the tubing, shaft and wheels.

"Spare the Rod, Don't Spoil the Child." Or, "how to Measure and Cut the Frame, and Shaft."

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I used aluminium tubing for the 'H Frame'. The frame looks like a H with two bars instead of one, going across it.

I used aluminium for lightness and corrosive resistance. Where I needed strong support or connecting pieces, I used steel and/or galvanised/painted steel parts.

I bought, 3 meters of 25mm X 25mm square aluminium tubing.
1 meter of 22mm x 3mm thick, round galvanized steel tubing (2mm thick would do).
2 meters of 10mm solid steel rod.
2 large plastic wheels.
4 galvanized 3/4 inch Nut and Bolts.
2 25mm Black square Endcaps.
1 Black Gloss Spraypaint can.
1 pack of teflon ended nuts. (Not used)

On hand I had; M6.5 Stainless and Aluminium pop rivets. 6x Galv 20mm washers. Two split pins. 50 mm square galv tubing.

I cut the the two uprights of the frame based on what I thought the ideal height the kayak should be at, when I was moving it.
This worked out to be 410mm long for the upright tubing.

Next I measured up the length for the round tubing, that would connect the kayak to the trolley frame, via the scupper holes in the back of the kayak.
These were 230mm long, allowing for, about 1/3 of the length to be inside of the trolley frame, when built.

Then, I rested the round tubes into the scupper holes, while the kayak was on flat ground, and slid the two uprights over them. I used this to get a measure of the distance for the cross members and an approximate length for the wheel shaft.

The cross members are at 300mm each.

I aimed to set the width, so that the poles would sit dead centre of the scupper holes.

I only got an approximate length for the wheel's shaft, at this point, as I would need to allow for spacing between the wheels and frame, the length of the shafts end, depending on which method I used to attach the wheels, also allow for the shaft end points, to be the right length to fit inside of the wheel end caps. I measured up for the shaft, after I got the first part of the frame built.

"The Hip Bone Connects to The, Thigh Bone." or "connection the Bars Together."

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Next, was to workout a way to connect the cross bars to the uprights. I had several options, weld the aluminium together, which I could not do, as I do not have an inverter or tig welder, just a gasless mig at this stage, or I could cut the tubing and slide and rivet the flaps over the tubing. This would be too weak a join. Or, as I came up with, join the tubes together with metal plates/strips.

I decided to go with a tongue and groove type setup. I would cut thin metal plate, with a tongue, or flange if you like, on each end, to slot into a groove cut in the aluminium tubing. I would then join them together with pop rivets. They would give the frame a really solid, strong, and unmoving build.

Now, to make the plates with a tongue on the end, I generally would have used my bench vice to bend a flat piece of metal over. But, my vice, via the evolutionary method, had grown legs, and walked, just before I moved house. So, that was out of the window for now.

It then hit me, what if I could cut some steel, that already had the required shape? So, seeing that I had some large square tubing I had bought prior, to make fence posts, I was in luck.
I cut some 45mm square galvanised tubing 22mm wide, with a 2mm tongue on the ends. The left over pieces from the tongued bits, became the flats used on the other side of the frame, to help fix it together.

To make it easy to see where I was going to cut, I put a blue marker line at the approximate measure point, and scored a mark through it, at the correct measure point. By 'bluing' the metal, then scoring a mark into it, it is much more easier to see when cutting. I used my old trusty metal cut off saw. You can just as easily do this with a hand grinder or hacksaw. As it was, I ended up using several methods to cut my parts. Not just the cutoff saw.

"Join Slot a to Slot B"

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Before I joined the frame together, I worked out where I wanted the wheel shaft to sit, and how far down I wanted the top bar to sit, to allow for the distance of the curve of the kayak's bottom.

I made the frame uprights length sit below the crossbar, to give it more distance from the open end of the tube, a weaker point on the tubing. Then I drilled the holes, in the sides, for the axle shaft to go through.
Once I had a H shape, I then slide the steel shaft in, put on two washers. between the wheels and frame, allowed 10mm for the ends of the shaft, to put in split pins, and I then cut it to length.
This was the second shaft I made, as I did not factor in enough room between the wheels and frame to stop them rubbing. The extra washer between the wheels and frame fixed this issue, two instead of one washer.
Once I did this, I cut and welded the first washers one one side only.

This is important.
Only weld the two washers on one side only, at this point. We add the other side, after the whole frame is finished being connected together.

To connect the piece of the frame together, used tongued plates put into slots I cut in the frame tubing.

I squared up the tubing and then laying the connectors on top, scribed a mark into the frame for the cuts to be make. I used a Dremel tool with a small cutting disk here, but you can do it with a cold chisel, placing a piece of wood inside and hammering the chisel down on the other side, cutting the groove, or you can drill a series of small holes inline, and then cut them with a chisel.

I then hammered the tongue and groove parts together, ready to be drilled.

Cutting Corners.

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I clamped the cross bar to another piece of tubing, to make it easier for me to keep the frame stable and square.
When I am drilling the holes for pop rivets, I have clamped the tubing down, and I use a set square to keep constantly checking that the piece's angles stay true. We want the frame to be as straight as possible, thought it does have some margin, it does not have much margin for error.

As per the photo's previously, the tongued plates, have a smaller than plate size tongue, on them. I ground the tongue down to size on my grinding wheel. You can do it with a file, but I like to save time, and it is easier. :)

When I cut the slots for the tongue, I made them slightly smaller than the tongues width, so that there would be a very tight fit and firm hold. Hence, why I hammered them into the slots.
After hammering them in, I check the frame was at 90 angles, before drilling the holes.

I drilled the holes all slopping one direction, to get the maximum load spread across the tubing. Eagle eyed views will notice that one corner, I did not do this. That was me stuffing up, because I was tired.

Once I had done all of the tongue and groove connectors to one side of the frame, I turned it over and drilled and riveted the the flats on the other side.

I made enough tongue pieces for one side of the frame. I reasoned that, the flat bits left over, would be enough to hold the frame together, with the tongue bits, along with the rivets stopping any side way movement or twisting. As a whole it works.

File That Under Smooth.

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Next, after I had competed the H frame, I leveled and smoothed all the ends. I used two hand files, a rough and a medium/fine, and wet&dry sandpaper.

The only place I left it rough, was on the inside of the bottom ends. I left the inside edge rough, so that the end caps would stay in better.

The end caps are put in, after I have done the spray painting and sanding.

Now that I have fully assembled the H Frame, I put the axle shaft into the bottom, and now weld on two washers on the other end.

Round Peg in a Square Hole.

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Now to do the tubes that go up into the kayak.

I ground one of the ends on each round tube. I rounded each end, so it goes into the kayak's scupper holes more smoothly.

Once the ends are ground, filed, and sanded, I put them into the frame's top uprights. About 1/3 will fit down to where the rivets are placed.
Once the tubes are in, then I used a hole punch, to make a small indent for drilling. As I was drilling into 3mm thick galv steel, it was very harsh on my cheap steel bit. Once I found a good carbide bit, I went a lot smoother! Even though I kept that bit cool with lube, it still required some bit regrinds.

I drilled the holes from the side, so that the nuts would be on the inside of the frame. The holes on the front face of the frame in the photo, are another mistake on my part. Once again, working while tired. Yes, I had marked it out beforehand, but I missed the marks. Sometimes you don't know when you are tired, because you are tired! :)

Anyway, after drilling the holes, I put the bolts in, and hammered them home. The bolts have square keyways on the heads end. This will hold the bolts when the nuts are tightened.
I used a washer and lock washer, to hold the nuts in place. You may wish to use a star washer or even some Locktight. You could also use nuts with nylon inserts.
This will be changed later, when I swap the bolts out for stainless steel nuts and bolts.

Even though the round tubing is galvanized, I painted them, when I painted the wheel axle shaft. They look better, and have some extra protection.

Paint by Numbers. or Paint by Paint.

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Just before I painted some of the metal parts, I ground the end of the wheel axle shaft flat on one side, at each end. I drilled a 3mm hole through this ground off flat bit. This is to hold the wheels on with a split pin and washer.
I was going to put nut on the axle ends, but when I tried to cut a thread on the axle shafts, it just would not cut, so I end up using the split pin method.

I don't put on the wheels till the penultimate step.

I used a cleaner on the parts to be painted, that removes any grease and grime.
Make sure to have clean surfaces before painting, so it adheres better, and stays on for longer.
I gave the parts, three coats of paint, pausing for around 20 minutes between each coat. I also sprayed paint up into the bottom of the uprights, painting the axle inside the tubing.
I painted the axles after I welded the washers on, as the welding would have not allowed me to weld on the parts, and welding would have burnt off any paint near by.

Once the paint had dried, I put the end caps in. I installed the round tubes back into the frame, put on the nut and bolts, cut the excess bolt length off, using a Dremel, and ground the bolt ends smooth with a file. I could have got out my angle grinder, but the Dremel was on hand, and it can cut through bolts quite well.

Have a Night Cap.

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Putting the trolley into the kayak as it is, will cause damage to the kayak's plastic skin. Thick as it is, it the trolley will cause damage at this stage. So, we need an end cap, to protect the kayak from the frames uprights.
Though I have filed, and smoothed the uprights ends, they are too thin to support the kayak's weight on it's bottom.

I used the soft end caps from 75mm poly pipe. I had a few lying around, so these were perfect for the job. Otherwise, down to the hardware store again.

I used a hole saw, which unfortunately, was 1mm to big to be an exact match to the round tubing. This meant that the caps would be a loose fit, instead of being snug enough to stay enough themselves.
Cable ties to the rescue!

I started out with a small bit, then switched to the larger hole saw. I did not have one a size just smaller than the tubing. The cable ties around the tubing, holds it on very well.

Penultimate. Or, Nearly There Yet.

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Now to put on the wheels.

Before I put them on, I put some grease on the axles. The axles does move, but I also greased the axles where the wheels make contact, as the wheels also move on the axle. This will reduce any friction on the wheels if they move, instead of just the axles moving, thus reducing wear and tear, and making it easier to move.

Once the wheels are on, the end washers and split pins put in, I put on the end caps that came with wheels. These will cut down on dirty and sand getting in, extending the wheels life.

And now, on the next page, the money shot.

Oh Yeahhhh!

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Here it is. In glorious action. Well. Stills.

Because of it's height, it is very easy for me to move the kayak around.

The trolley can be stored on the kayak while you are paddling it, by strapping it down flat, or putting it in upside down, via the scupper holes. Though my preference would be to leave it in my car. Less weight to paddle around, even if it is very light. But, if you can't, you can take it with you.

Hope you enjoyed my Instructable, and if you wanted to make one, hope this helps.

Thank you.

PS. or Other Things I Can/may/will Do.

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A few things that I am going/may do, in the near future.

The bolts that I used, I got at the place I bought the aluminium tubing, separate from where I bought the steel. I am in the very near future going to replace them with stainless steel 316 nuts and bolts. I could not get them at the time, as I had over spend on my account. Regular bolts costing less than a $1, stainless marine grade, far more than a $1 each.

I may yet put paint over the tongue connector plates and flat plates.
I have used stainless, or aluminium rivets when I ran out, but the plates are galv steel, and a bit of paint may be a good idea.

I have used different metals, so electrolysis maybe an issue. With joining different metals together, there is an electrical potentiality between the joints, increasing oxidation (rusting), so I may add a sacrificial plate to the frame.

On the round tubes, I am thinking of sleaving them or plastic dipping them.

I might end up painting the whole trolley frame, though I do like the look of the bare metal.

That is it for now.

A final note aside.

A friend asked, "But, will it blend?".
I relied "Yes, but not only that, it comes with a free set of steak knives!"
That picture is for him. Hi Jammie.