Round Road Project
A "round road" is a device that allows a massive concrete block to be rolled. The contour of the round road keeps the block's center of mass moving horizontally. For this reason, the block's weight is not a major factor, and a small amount of static friction must be overcome to set the block in motion. Two years ago, I built a successful round road with a 1400 pound block. This page documents the construction of a new round road with a 2000 pound block. Also, I designed and built a separate pivot system that would allow one person to use the same round road segment to move the block anywhere and in any direction.
A wooden form was built to hold the 2000 pounds of concrete. Several bolts were inserted into the wooden form. These bolts would later hold 2X4's on the outside of the block to keep it aligned as it rolled down the road. Victor Pantoja and Alex Contreras came by to help load the form with concrete.
The round road is built from 1X12 pine boards. Three of these boards are glued together on each side of the road. 2X10 cutouts are used to secure each side of the road together. The round road worked, however, it takes a good amount of force to keep the block moving. It does weigh 2000 pounds.
Round Road Demonstration Video
I came up with idea of developing a pivot mechanism for the round road. It would allow someone to use the same round road segment to move the block anywhere and in any direction. The system works by having the block move several inches past a fulcrum (7/8'' bolt). This causes the other end of the round road to lift up. Now, the entire weight of the block and road is on the pivot point. If a large weight is located on a single point, it is very easy to rotate. After the weight is on the pivot point, the round road can be rotated half a turn, the block can be rolled to the other end, and the process can be repeated. This allows for the same round road segment to be used. During the building process, I only made one pivot point. I never did build the full system with two pivots.
The actual pivot point is a 7/8'' fine threaded bolt. It had a rounded head. The bolt was connected onto one end of the round road with a 2'' piece of steel channel.
If the weight of the mechanism moved off center off the fulcrum, it would tilt and slam on its side. For this reason, several small wheels are used to stabilize the mechanism. If the system starts to tip, the wheels will touch the ground and keep it stable. If conditions are perfect, these wheels carry no weight. They are only there as a protection. A circular piece of wood was also cut out for the wheels to roll on.
The pivot mechanism worked very well. With one hard push, the system would rotate 220 degrees by itself. If a pivot mechanism was built one both ends, the block could be moved anywhere.
|Carried 360 degrees||http://www.youtube.com/watch?v=P7dk63Il5rI|
|Pushed 220 degrees||http://www.youtube.com/watch?v=FPZp4IgHcLM&NR=1|