The Building of the Climbing Wall

Many freshmen arrived at East Campus, and we immediately used their slave labor to build an assortment of ridiculous wooden structures.  Construction of the climbing wall went very quickly and fairly smoothly, and I didn't really take any pictures of the process.  Fortunately a more talented and better equipped photographer got some good photos and video of the process.  All photo and video credits to Billy Demaio.

Some of the construction footage compiled:



Assembling the uprights:

Building the rings.  Unfortunately no pictures were taken of the process where we lifted the rings onto the axle.  About 10 people lifted each ring, while I stood on the top of an upright to manipulate the axle into place.  Someone on the other side of the axle pushed it through, while another couple people held a crutch in place to support the weight of the rings and axle.  This was repeated about 6 times, because we had to remove two of the wings to widen the holes in the plywood.

Some other of the courtyard structures.  In the background is most of the four-story fort.  To the right, part of a ride called the "Frosh Wash", and in front to the left an impromptu swingset.

Before we put the plywood and climbing holds on, we found a bunch of fun activities to do with the structure:




The climbing actually worked well.  We found a brake position that worked for a fairly wide range of climber weights.  Two people on the sides of the cylinder would help turn it to make sure no one climbed too high up.

REX 2013 Project: Rotating Climbing Wall

Every year during the freshman orientation, residents of my dorm (East Campus) build a variety of large wooden structures in the courtyard between the parallels.  Or rather, they design the structures, and then enlist the labor of excited freshmen to actually do most of the construction.

This summer, as not-a-frosh, a couple hall mates and I are joining in on the design side of things.  Our plan is to build a giant rotating cylindrical climbing wall.  Basically like this.  The cylinder you climb on will be 12' in diameter,  8' long, with the axle about which it rotates suspended 8.5' off the ground.

I started out by working on the design of the rotor.  I began by making these hexagons out of 4 x 4's.  Then I checked the mass properties in Solidworks, saw that it already weighed over 800 lbs, and started over with 2 x 4's.  

Here's the completed rotor design.  The hexagon is extended to a dodecagon around the outer edge.  The  board that make up the edges will be cut so that the actually make a circle, rather than a polygon.  The outside of the rotor made of sheets of 1/2" plywood.  The curve radius is large enough that I don't think it will be too difficult to bend the wood.

How 'bout that moment of inertia?

Here are some renders with a base added in:

The axle is a big steel tube, and it passes through a giant bearing on each side of the base.  The bearings, combined with the huge moment-arm on which a climber's weight acts means that climbers should have no trouble turning the rotor.  In fact, it may be too easy.  To limit the rotation speed, the rotor will have a brake attached to it.  So that the spokes and axle don't have to transmit any torque, the brake will act on the outside of the rotor.  A car wheel on another axle will press against the outside of the rotor on one side.  This wheel will have an adjustable brake attached to it.  I do not yet have a car wheel, but I do have a brake disk and caliper.  I think this 1' diameter truck disk will be sufficient.  The caliper, which came from the shop of a now-defunct electric car team, should also be adequate.

For lack of something better to do with the 3D printer I won, I printed a miniature model of the structure:

We've contacted some climbing gyms and climbing hold manufacturers to see if we can get the climbing holds sponsored for free.

Construction will begin toward the middle August.