Model Turbines

[Turbine GuyParticipant @turbineguy]

I glued Rotor 6 PLA shown in the last post to a shaft and ran it in Tangential Turbine 6 shown in the following drawing and spreadsheet. I made an error in guessing where to glue Rotor 6 PLA on the shaft which resulted in getting much higher compression on the spring than I wanted, but as you can see in the spreadsheet the performance wasn’t that bad for the first test. Normally I would run several tests to find the optimum position of the rotor in the housing and the best spring compression before adding the performance in the spreadsheet. When I disassembled the turbine to reposition the rotor on the shaft, I found that the extension of the rotor on its outer face had broken off. I mentioned in the last post that the rotor was designed to be cast in bronze and had several areas that were two thin for a material like PLA. I am in the process of trying to fix the rotor assembly but it will require enough changes that it will have to be called a new assembly.

[Michael GilliganParticipant @michaelgilligan61133]

I must confess that I only dip-in occasionally  … but I am always impressed by your dedication to this research.

Thanks for sharing it

MichaelG.

[Turbine GuyParticipant @turbineguy]

Hi Michael,

Thanks for your kind comment.  I try to show how well turbines have performed for several designs of varying complexity and requiring different equipment to make or parts to purchase.  I hope that this information will help people thinking about making a model turbine what they can expect in performance for models like the types tested.

Hope you are doing well,

Byron

[Turbine Guy]

On Turbine Guy Said:

I glued Rotor 6 PLA shown in the last post to a shaft and ran it in Tangential Turbine 6 shown in the following drawing and spreadsheet. I made an error in guessing where to glue Rotor 6 PLA on the shaft which resulted in getting much higher compression on the spring than I wanted, but as you can see in the spreadsheet the performance wasn’t that bad for the first test. Normally I would run several tests to find the optimum position of the rotor in the housing and the best spring compression before adding the performance in the spreadsheet. When I disassembled the turbine to reposition the rotor on the shaft, I found that the extension of the rotor on its outer face had broken off. I mentioned in the last post that the rotor was designed to be cast in bronze and had several areas that were two thin for a material like PLA. I am in the process of trying to fix the rotor assembly but it will require enough changes that it will have to be called a new assembly.

I fixed the rotor assembly mentioned in the quoted post by glueing Rotor 6 PLA to a set screw collar as shown in the following photo. I used the glue from my fly tying kit that was designed to bond plastics to metal and it was strong enough for me to finish the testing of Rotor 6 PLA. I was able to try various positions of the rotor in the housing and try various amounts of spring compression by changing the number of shim washers. My thinnest shim washers are only 0.001” thick so I can find the ideal location of items very close to their best positions. It took me several tests to find the ideal position of the rotor assembly shown in the following photo but the ideal position did not get any better performance than I got with the original rotor assembly as shown in the drawing of the quoted post. Reducing the spring force pressing the rotor against the inner ball bearing did not increase the performance so apparently the original assembly as shown in the quoted post gave the best performance for Rotor 6 PLA and the spreadsheet in the quoted post has the best performance for the Tangential Turbine 6.

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