The Test Chamber

 

In the last post I had the Platform finished. The Platform is a level surface that is at the hight of the 4' opening in the Connector. The Test Chamber will sit on the Platform.

Following the plans for building a standard KW wind tunnel I first cut all the pieces to length.

For the assembly I use a Kreg tool to make the pocket holes for the screws. I highly recommend this method for assembly and worth the investment if you don't have one.

The hinges that hold the top on were inlet with a router so they sit flush to the surface. This way I did not need to notch the side pieces so that they clear the hinge spine when being closed.

Another change to the standard plans was for the side covering material but on the outside. The standard KW tunnel uses 4 mil clear plastic and this does just fine at 4 m/s wind velocity. However with the increase in wind velocity for this tunnel I will use 1/4" Lexan sheet material. I routed in a 1/4" deep rabbit on the inside of the sides. This will keep the side surface area smooth. And provide protection to by standards against blade failures. 

The top of the Test Chamber is made out of 3/4" MDO as I had a piece left over from the Platform. Assembly went well.

Hinges were attached on the inside of the pre-assembled sides. The frame was rotated so this could be done in the down position on the floor. The Test Chamber sides and top fold flat for easy transport and storage when not in use. 

Another big concern is for protecting the fan blades from any pieces of broken turbines. It has to be strong and fine mesh but not create a lot of resistance to the flow of the wind. My solution is to use a piece of cattle panel for strength and then cover it with chicken wire to make it fine mesh and not create a lot of wind resistance. It reminds me of the seen from the Blues Brother's movie when they are singing in the bar.

And then just when you least expect it you do this. On both sides no less. The draw clamp was supposed to clamp the top to the side. What a bone head move.

This way works a whole lot better.

And here we have the Test Chamber in place. Tomorrow I will be working to install gasket material on the joint connection areas to minimize any air leaks. Then I'll do some take down and assembly runs with it before we fire this bad boy up and get some wind velocity readings.