Reply To: Model Turbines

[Turbine Guy]

On Turbine Guy Said:

I started to have rubbing when running Axial Turbine 4A regardless of placement of the rotor. It appeared to be due to excess tilting of the rotor. Axial Turbine 4 has the option of adding a ball bearing in the cover as explained in the 15 October 2022 post on page 17. The combination with three ball bearings is called Axial Turbine 4C as shown on the following drawing. I thought this option would significantly reduce the rotor deflection and allow the spring to keep the rotor pressed against the inner bearing but might reduce the performance due to the added friction of an extra ball bearing. When I ran a test of Axial Turbine 4C the results were the same as I was getting with Axial Turbine 4A before the tilting became a problem. Apparently the extra rigidity allowed the rotor to get closer to the cover increasing the performance enough to offset the added friction. I will run a few tests to break in the new ball bearings and record the performance in the next post.

The following spreadsheet shows the best performance I was able to obtain for Axial Turbine 4C in the 11/27/2024 test after I ran the turbine several times to bed in the ball bearings. Adding the extra dental ball bearing actually increased the performance when compared with Axial Turbine 4B that was identical except for the extra ball bearing.