Steve Hobley's Fabrications Using the blackToe CNC Machine
Steve Hobley has done many projects using his blackToe Machine, including a Theremin Stand and a spectacular wooden geared clock.
Steve Hobley'sFritz Lang's Theremin Stand:
Theremin: A musical instrument that functions without any physical contact with the actual musical instrument. I've always though this is the perfect instrument for conductors! Don't worry, this is not a theremin webpage, but I want to show you a theremin stand that was fabricated by Steve Hobley using his blackToe CNC machine. Steve stated that the use of elliptical shapes really shows-off the benefit of using a CNC machine. It's true, especially with the well formed slight curves and curvy forms spanning the legs. It would be interesting to know if the form itself has some influence on the musical note. Check it out on his site.
My favorite part of the design is actually on the back, where the coils are held by two circular caps and a collar in-between. The lower front, where the speaker is mounted has a nice cohesive look with its elliptical design.
Steve elected to create the general form with the CNC machine and smooth the hard edges by hand. This is quite an appropriate use of the CNC machine. Let the machine do the difficult part of the fabrication, but still allowing the human to get their hands dirty.
Steve has updated his clock. The clock now has a face, and the gears are painted to easily distinguish the major time functions. But the most important detail in this update is Steve's journey into tool changes during the clock face fabrication. On his blog (Carving the Clock Face), he details the process he used to change the end mills to achieve his desired results.
Wall clocks that exhibit the exposed gearing, pendulum fabricated out of wood, is a great showcase for clock functions and provides a great example for what CNC Machines can do well. Steve Hobley, using the blackToe CNC Machine kit, fabricated all of the gears for this clock.
Steve Hobley always impresses me with his creative projects and this clock is an example of how he uses creativity in his mechanical design and striving for efficiency with less frequent pulse to the coil to move the pendulum.
Mechanically, he is using a 15 tooth ratchet, compounded with a 15 tooth gear that turns a 60 tooth gear. This gear turns another 60 tooth gear that is connected to the main shaft of the hour, minute and second hands. There is a compound gear with 10 teeth that turns two gears: a 32 tooth gear and a 108 tooth gear. The 32 tooth gear contains a compound gear with 8 teeth that turns another 32 tooth gear connected to the main shaft (hour, minute and second hands). The 108 tooth gear contains a compound of 18 teeth that turns another 108 tooth gear. The latter 108 tooth gear is also connected to the main hour, minute and second hand shaft.
Steve kept all gear centers along a vertical plane. This makes for a convenient means to stand the mechanism. Additionally, the gear centers have an adjustable groove on the frame so that the gears can be adjusted for best gear meshing.
To drive the pendulum, Steve is using an ATMega controller acting as an Arduino (contains a bootloader that allows for the ease of using Sketches and simple code transfer). The controller receives a signal from the pendulum when it is at vertical at which point, a voltage is applied to a coil, pushing the pendulum. The creative aspect to this is Steve determine that this pulse is not required at every pendulum swing.
Check out Steve's blog for detailed information.