Smith Spring Machine

Find a way to adapt common gym tools for a reduced gravity environment and design a workout routine that can minimize bone and muscular loss while being fun and easy to use during a long term mission. In doing so consider constraints regarding weight (equipment should weigh less than 500kg) and dimensions. Consider incorporating virtual reality to simulate a jog through an astronaut’s favorite Earth destinations or incorporate gaming to motivate users.

The Smith machine is a piece of equipment used in weight training. It consists of a barbell that is fixed within steel rails, allowing only vertical or near-vertical movement. So how can we modify it to work in reduced gravity ?

Our idea is represented in using

tension springs instead of

weights.

Tension springs are designed to give a specific pull force when extended to a specific length.

•Easy to Manufacture: Spring manufacturing is relatively simple and versatile process. Spring manufacturers use the latest in coil winding, heat treating, and finishing equipment, which dramatically reduces the overall production time.

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•Less Expensive: Extension springs are generally manufactured using inexpensive materials like hard drawn steel, music wire, and standard spring steel. This makes extension springs extremely economical for industrial applications.

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•High Reliability: Extension springs are known for their ability to work under strong acting forces in an application. They are extremely reliable and can be used for long periods of time.

and these are Advantages of Extension Springs.

k = Gd^4 /[8^3D na] f=k * ∆x
G = E/2(1 + V)
d = D outer - d

If Spring constant is 1 LBF/inch

it takes 1 lb of force to travel 1 inch of distance

1 LBF/INCH= 1LB of force per 1 inch of travel distance

Meaning of Variables in Above Formulas:

G = Shear modulus of material
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Spring calculations

• Burning Astronaut Pee - Smarter Every Day 149: https://www.youtube.com/watch?v=05oOst9kZXQ&t=2m
• Advanced Resistive Exercise Device (ARED):http://www.nasa.gov/mission_pages/station/research/experiments/1001.html