# STELR Wind Turbine Blade Angle

This video is going to show you how to
measure the wind blade angle when you’re doing STELR wind energy experiments. The STELR wind blades come in three sizes: there’s the long red ones, the medium
blue ones and the short yellow ones and today I’m going to use two short yellow
blades and show you the process for measuring the angle. Once the blades are
in the hub you can look very carefully around the edge of the socket where the
blades sit and you’ll see some little marks and each one of those is 15
degrees. So you can just count around a number of those, so if I count two that’s approximately 30 degrees and this one is also 30 degrees. If you want to measure the blade angle a little bit more accurately you can use
the STELR protractor. There’s a file that you can print out that’s available online or on the STELR USB and then once it’s laminated you can cut out each
protractor individually. You’ll see when you look closely at the protractor that
the zero mark is not right at the bottom of the protractor, it’s a little way up.
So to measure angle, you take the protractor and you place it around the
base of the blade and carefully line up the zero mark to the division between
the two halves of the hub. If you do that and then you look down the blade
carefully you can line the blade up with the correct angle. So I’ve got this at 30
degrees now and I’ll measure the other one and check that it is also at 30
degrees. Now we’re ready to test two yellow blades both at degrees. When
you’re doing this, double check that both the blades are facing in the same
direction that they don’t have the vein at the back and also make sure you’ve
measured the blades at 30 degrees so that they’re both pushing in the same
direction one of them is not 30 degrees one way and 30 degrees the other way. you