Thursday, August 21, 2014

Shade Structure

I want to buy a shade tent for when I go to the beach with friends, it needs to be big enough to accommodate a group of people. I was walking into tent shops and I liked the look of this Coleman Event 14 but at the time I didn't have $300 to spare (I've seen it advertised for $250 in other shops these days). The sales guy/manager in the store I was in jerked me off at that time so I don't want to give him business and haven't been back

Fast forward a couple of years, still haven't purchased a shade structure. A Google search for shade structure gives me http://shelter-systems.com/ and I like what I'm seeing. It really fits with the DIY culture I've been getting into lately.

I'm happy to spend incremental amounts, even pay a little more if I'm learning something. I decided its something I believe I can make, so I get designing.

Blender is a  great free tool for lots of reason :D
Initial Design


Now I happen to be extremely lucky, My measurements worked out such that the entire structure is made up of basically the same pieces.So I went to Bunnings hardware store and purchased enough pvc to construct a prototype joined together with tape.

As you can see from the photo's that its pretty dodgy, I didn't measure the placement of anything on this first run and it showed some weaknesses at the opening, but the theory was OK, it stayed up. I changed the design slightly to make it more robust at the opening, otherwise it would push forwards to much and look lopsided.


So with this updated design I wanted to test the measurements for the interior cloth, I used string to approximate the forces, it wouldn't simulate sheer force but I 'm not fussed. Time for setup round two

before looking at the photo's imagine that for a whole hour we had the kindergarten children next door shouting "what are you doing", "what are you making" over and over at us, it was rather funny. and even if we gave them answers they forgot it in two seconds and started shouting at us again. :) cute kids.








So this gives a much nicer impression of the structure, but even better is this:

Video Link
You can see that there is a diagonal force weakness  which allows the structure to fold flat, now given that its held down I don't imagine that this would be a problem. A horizontal circle above the headline would sort that out but I'll leave it as optional in my design as I don't forsee it as a major problem. Also you can see that the tubing I'm using is quite thin, 20mm makes it look like jelly :D I'm OK with this as its only intended for wind and sun resistance. but I will really see when I add the cloth. I could simply choose thicker tubing next time.

Total Tubing:




And I've made a start on the cloth dimensions too but I personally don't have access to a sewing machine.
so that's next..

So far I've spent more that I needed to(tools, mistakes etc) also I didnt optimise for the lengths I was purchasing though so I had a bit of  unnecessary waste. ie 6m lengths / 160cm is 3+ extra.. if I chose 150cm lengths...  if I purchased the tubing from a wholesaler rather than a retailer. might even be able to scrounge offcuts. basically there is lots of room for improvement in all areas. But that's the fun, its totally worth the cost. And I get to share my mistakes with others so they don't have to make them :D