My mother is approaching 80 and has decided to take up kayaking. She can handle everything about the boat, except getting it on and off the roof. After some searching on the internet, she found some ideas that could work but did not quite satisfy her needs. Then, she passed the whole thing on to me. This is the best of both.
In short, the kayaker will lift the front of their kayak to the device, which will enable them to roll it up onto the roof. The "car topping helper" will carry the load while the kayaker directs it.
It attaches to the car with a double suction cup device, the type used by construction people to move large plate glass windows and heavy counter tops. The structure is PVC pipes and the wheels made for a lawnmower.
Step 1: Materials
The materials are basic, but some of it had to be found online. This is for EACH device you build.
Double Suction Cup: The type used for safely handling glass panels, sheet steel and smooth laminates. Two suction cups provide lateral stability, and the handle between the two makes for a convenient bar to attach the frame to. I bought the Woodstock D3042 Double Suction Cup from Amazon because I liked that it was yellow. They are very strong; my son attached them to the door frame in our kitchen and hung from them.
PVC Pipes: These make up the structure:
- 1" PVC Tee with Threaded Branch (2): The straight part was smooth but the branch is threaded so you can reduce.
- 1" to 3/4" Threaded Male Adapter (2): To reduce from 1" Tee to the 3/4" the rest of the device will be.
- 3/4" PVC Tee Smooth (2): Will need priming and PVC cement.
- 3/4" to 1/2" PVC Male Adapter (2): This will narrow the channel as the axle comes out.
- 3/4" PVC Pipe: After buying a 10' length, I only needed about a foot for each device.
- PVC Cement: To hold all of the pipes together.
3/4" to 1 3/4" Stainless Steel (Hose) Clamps: To attach the device to the double suction cups. I make sure the tightening head is hexagonal to take a socket for tightening.
6" Plastic Wheel: A lawn mower wheel. They used to be quite common, as our landfill seemed to be cluttered with broken mowers. Of course, when you want one there are none to be found. They need to spin a bit with the weight of the kayak, so the cheap ones on bar-b-ques might be too flimsy--go for this quality. Note: The axle hole is 1/2".
1/2" Axle: Like the lawn mower wheel, the simple metal rod is disappearing from my landfill. You'll need about a foot for each device.
1/2" Axle Nut: These tap onto the end of the axle rod to secure the wheel. I include the photo of the bag because no one at Home Depot could tell me what they were called, so they could not look it up on their computers to find it. Everyone knew what I was talking about, though, but because they are such a small item in a huge store it took a while to find them.
With this as a model, you will no doubt figure out ways that work best for you and materials that bypass the need for adapters and the like. Put them in the comments section, please. This worked for me and the limited access I had to PVC and other structural materials.
Step 2: Cut 1" Tees in Anticipation of Attaching to Double Suction Cups
The most difficult part of this entire design was figuring out how to attach the whole device to the double suction cups. I thought it would be easy, but was wrong.
When buying from Amazon, it was noted that the handle was hollow. My plan was to cement a PVC pipe inside of it and attach 90 degree elbows for the vertical frame. The inside of the handles are just a smidge narrower than 3/4" PVC pipe. I found another pipe that was a little more narrow, but when I attached the elbows they interfered with the arms that work the suction mechanism. The frame was going to have to attach to the exterior of the handle.
It is clamped on.
In order to create a platform that will match, cut the 1" PVC tees down the length. I used a table saw, carefully. The 1" arc matches the handle of the double suction cups well enough.
To offer the most lateral stability, cut off one end of the tee so that you can push it to the end of the handle. Two tees fit nicely.
Because the rest of the device is 3/4" you will need to use an adapter that offers a female smooth end to insert the 3/4" PVC pipe later.
Step 3: Crafting the Frame
You can see from the photos what the finished frame will look like.
My 3/4" PVC pipes were cut to 3" each (3 total). I cut them down a bit after fitting everything together
Note: The piece that links the left and right verticals together, when fitted in snug, should cause the "feet" of the two 1" tees to touch but not overlap.
Note: The vertical pieces that connects the 1" tees to the 3/4" tees need to be long enough so that, when the wheels are attached, those wheels do not interfere with the movement of the arms that work the double suction cup mechanism. At the same time, the longer you make them the higher center of gravity you are creating--that will weaken the device while it handles the weight of your kayak.
Put the whole thing together without cement, and rest it on top of the double suction cup handle. Hold the wheel to where it should go. Is there any interference? If okay, cement the PVC together (but don't cement it to the handle of the double suction cups--you'll use clamps later). Let dry.
Note: If you have not used PVC cement before, know that it dries fast. If one tee is not in alignment with another as you fit it in you will be unable to change that. One way to make sure it is all on the same plane is to lay it flat on the workbench as you work on it. Of course, read the directions of the PVC cement before using. You'll need to rough up those joints!
Step 4: Attach the Wheels
The wheels will take some weight, but they are not turning much. Of course, you want them to spin easily but I did not feel the need for washers and such.
The 1/2" axle should be long enough to go through the frame, two wheels and still have a 1/4" on each end for the axle nut.
Once the axle is through and the wheels are on, use an axle nut to keep them on. Again, Home Depot could not name them (I thought they were called "caps") so here's a photo. They go on with a hammer and stay on.
Step 5: Attach the Device to the Double Suction Cups
Originally, I had thought of using PVC cement to attach the frame to the double suction cups. The 1" tees, cut, did not quite match the arc of the double suction cup handles so I would have had to clamp them for drying--it was unclear if the tension would still be present and, eventually, cause it to detach at an inconvenient time. More important, by using the clamps my mom can adjust the angle of the frame once the double suction cups are attached to her car. One will be on her trunk, while the other on the rear windshield. At this time, I am not sure if a straight vertical will do the trick or adjustments will be needed. In using clamps, my mom and I have options.
Unscrew the clamp until the one end comes out the mechanism. Then, put the frame in place on the handle of the double suction cup and loop the clamp around both. Feed the clamp end back into the mechanism and tighten.
Adjust vertical angle as needed.
Step 6: Suction to Car
Make a second (or third) device for your car.
These suctions cups are seriously strong bonding.
Line them up to create a rolling path for your kayak. My mother plans to put one on her trunk and another on the rear window. For this Instructable, I just stuck them on the hood and front windshield. Once you get the nose in the first device you will pick up the other end and walk it forward. The wheels should be wide enough to offer stability, and the double suction cups should hold it all tightly.
Once on your roof you will tie it down or do what you do. Enjoy.