Friday, October 2, 2009

Tesla Turbine

The Motivation to Build

Sometime multiple things need to come together to make things happen. Sometimes people need to come together to create the drive for things happen as well. The motivation for this project came about as a father-son lets-build-something-cool in the shop and spend less time in the 'virtual world' of video games. argh..sigh... Dad.... Perhaps motivated by my observation that my son's interests are different than mine, as mine were different from my father's, but realizing all are linked by a common drive for understanding. Or maybe it was just a nice distraction to build something in the shop while talking between generations.

The Project

This project is a high-speed turbine, based Nikola Telsa's idea, as implemented with plans found here:
www.instructables.com/id/Build-a-15%2c000-rpm-Tesla-Turbine-using-hard-drive-/


and also here:
www.blogger.com/www.phys.washington.edu/users/sbtroy/Tesla_Turbine/Tesla_Turbine.html

This project came about after a few things came together
(1) watching a PBS show on Nikola Tesla www.blogger.com/www.pbs.org/tesla/,
(2) a chance surfing-stumble across a related link on the DIY website www.instructables.com/, and
(3) a sudden thought on what to do with a bunch of old hard-drives piling up in the junk-bin.
The first cool part here was taking apart old hard drives. It is amazing the converstation you can have with teenagers when you are busy on a fun project. Needed was the aluminum platters contained in each drive. These serve as the smooth serviced disks that Tesla used in his turbine.


Cutting the Ventalation Slots in Platters
The Hard Drive platters serve as the turbine disks. However they require slots cut in them to allow for the air (fluid) to exit dear the center of rotation. Three arcs were cut with a 0.250" end mill. Rather than use a rotary table, the CNC milling was machine was given some quick GCode.

















This is always fun to watch when the machine is cutting on its own. A simple clamping jig allowed for disks to the aligned on the table repeatedly. These disks are made of aluminum and cut fairly easily. The picture above shows the end result along with the needed spacer.


















Cutting Ventalation slots in the housing
Ow this posting is skipping a lot of steps. Below is a video of the ventalation slots being CNC'd into the side of the housing. Cutting in plexi is real easy. Can't say I know the actual cutting RPM, trial and error gave a nice result. Going too fast melts everything.





Stacking the Disks on the arbor
Below you can see the arbor carrying the disk stack. This build used 8 disks separated by about 0.030"





















More to come....