A pair of skis
2' pvc pipe
foam floor padding thingy
1' wide nylon strap
nylon strap buckles
I don't exactly remember what all I used.
Skis: I found the skis I used at REI on closeout, clearance,we've got a bunch of these and NEED to get rid of them for a low, low price of $17. They are simply a pair of child's cross country skis. I think they are 110cm long. Had I not stumbled on that incredible deal, I'd have visited thrift stores, watched garbage piles and/or made my own from pvc maybe?
2' pvc pipe: Environmentalists relax, yes I know pvc is bad stuff. I found a piece of it in the rafters of my garage. It must have been leftover from a project performed by the previous owner.
electrical conduit: I bought mine at Home Depot. No real mystery here.
foam floor padding thingy: This was one of those puzzle piece square foam play mat things. I used a scrap I'd kept after cutting it to fit the floor in my basement so my little one would have something softer than concrete on which to play. Approximately 1/2 of a 2' x 2' square, so 1' x 2' was perfect.
old seatbelt: When I was in college I worked in a shop maintaining the college's fleet of vehicles. At some point we had a big 15 passenger van with only the front two seats. Strangely whoever removed the seats left the seat belts. We removed the seat belts and the guy in charge threw them in the trash. At the time, I didn't know what I'd use them for, but I knew I'd think of something eventually. I saved them. Now 10 years later, I've finally thought of something to use one of them.
nylon strap: More stuff I had on hand. Most of it came from an old mounts on the back of your car bike rack. I think one piece was something I picked up on the street and the final two were from a backpack maybe?
strap buckles: Surprisingly I had these on hand too. Maybe from that backpack or ???
Step 1: The Ski Plan
Step 2: Implementing the Ski Plan
Now I needed a jig to bend the pipe around. I happened to have some 3/4" plywood scraps and some scraps of 2X4. I screwed the 2X4 pieces to the plywood in what looked to be about the right arrangement.
Ready to bend! I used a heat gun (think turbocharged hair dryer) to heat the pipe where I wanted a bend. I heated it until I thought it would bend easily, making sure to rotate and heat evenly. I'm impatient. I probably should have heated it a bit more as the inside of the bends kinked when I put it in the jig. No big deal as those areas are going bye-bye anyway. So, lather, rinse, repeat until I've got two \___/ shapes out of pvc pipe.
Now to open those up so the wheel will nest in them. I used a hack saw to split the pipe along what was previously the length. My hacksaw has this nice feature where you can put the blade tilted 45 degrees relative to the frame. Saw, saw, saw. Done! now I just need to attach them to the skis.
Step 3: Attach Sockets to Skis
Now things are really taking shape. To attach the wheels to the ski sockets, I decided on a couple of small bungee cords per ski. I may decide this isn't firm enough later, but for now it seems to work well.
Step 4: Take a Summer Break!
Step 5: Back to Work
I found that 1" EMT conduit fit the sockets in the trailer quite nicely.
I bent two pieces of conduit into shape ( a right and a left) and connected them together in the middle. The connection would be right behind the skier. To connect them, I took a 3 inch scrap of tubing and split it open lengthwise. I then rolled it tighter using pliers until it would just fit inside the conduit. I stuck it in one piece about half way and then into the other piece. I then secured each half with two sheet metal screws each.
To keep the tubes in the trailer, I drilled some slightly oversize 1/4 holes through the tube. The sockets on the trailer already had 1/4 inch holes. A couple of pins down through the holes completes the connection.
Now all I need is a hip belt.
Step 6: The Hip Belt
The piece of padding was about 12 inches wide and 24 inches long. I needed a piece about half as wide and twice as long. Using an electric carving knife I split the foam into two 6 inch by 24 inch pieces. Incidentally, this is the only time I've ever seen that electric carving knife used. It is probably as old as I am. I got it from my mother. I don't recall ever seeing her use it. It worked beautifully. Next, I scarfed the two pieces together. I used the carving knife to taper each piece and glued them together using Weldwood contact cement. It is stinky stuff, use it outside. I now have the 6 x 40 piece of foam I need. "Wait" you say, "I thought the short pieces were 6 x 24, shouldn't you have a 6 x 48 piece?" No, the scarf joint eats up some of the length.
Ok, now how to attach the seatbelt to the foam so the padding stays under the belt? I decided to cut some slots in the foam and I'd insert the 1" wide nylon strap through the slots and buckle it around the seatbelt. This would allow the seatbelt to slide in relation to the foam so when it is adjusted for different waists the buckle will still be in front and the padding can still be centered. I cut the 1" straps to length (leaving plenty) and sewed them onto the buckles in the appropriate places. I just did a straight stitch across these as they won't really be holding much.
I also needed to make the seatbelt into one piece as currently it was two pieces. I cut it to length, overlapped the ends a couple of inches and sewed them together using the X pattern you see on strappy things. I figure there's a reason why they sew that X pattern, it must be strong. The thread tension on the machine was a bit off for that thick seatbelt. I should've done a test piece and gotten it right. I didn't. My stitches are kinda ugly on one side of the belt. I also made sure I used a hefty needle (designed for jeans) and hefty thread (also designed for jeans) for this.
Step 7: Attach Hip Belt to Tubes
Step 8: Performance Update!
1) It'll push/knock you down quite quickly when trying to go down hills. Be careful! Going up hills other than the very smallest, very gradual incline is nearly impossible (not surprisingly). Knowing that, I'll have to plan the locations where I ski accordingly.
2) When skiing/walking the trailer bounces forward and backward. This is due to the single connection point on the belt. The belt flexes into a V shape behind you when you pull forward. To fix this, I inserted a piece of 1/4 inch plywood between the seat belt and the 1" nylon straps (outside side of the seat belt). This prevents the formation of the V. I should add a picture detailing this.
3) The bungee cords used to attach the skis are adequate, but I'd like to try Velcro straps as I think they'll be easier to install/remove.
4) The seat belt is hard to get as tight as I'd like (loose = more bouncing). This is because pulling on the 'tail' to tighten it tends to simply rotate the belt around one's waist. Looking at backpacks, a lot of them have a 'tail' on each side to pull to prevent this. That setup also keeps the buckle centered in front of you.
5) Even though I haven't been skiing much, the skis for this project have been useful. My wife and I do typically have the time and the energy to go for a walk in the evening. Around my house, the roads often aren't plowed quickly so there is a layer of packed snow in some places, loose snow in others and sometimes bare pavement (the more traveled roads). I started taking just the skis along on our walks. On the bare and packed snow areas, the wheels roll with little resistance. On the loose snow, it can be a challenge to push the trailer/stroller. When I hit the packed/loose snow, I simply slip the 'socket' of each ski over each tire. I don't bungee the skis on, they stay put just fine. Even if one were to slip off, I'd notice it immediately and putting it back in its place would be quick and easy. It is much, much easier to push on the skis. When I reach a clear area of road, off come the skis in an instant!
6) Overall, I have been very happy with the outcome of this project. Over this past winter I also built a "jogging wheel" for the front. I need to instructablize that project. I also need to build a ski for that front wheel to use when walking like I described in the previous paragraph. No doubt I will continue to refine and improve on my Chariot trailer/stroller - well, at least until my son grows out of it. I'll endevour to instructablize and update as I do. I'll also update if/when I get to do more skiing.