Here is an idea I had the other day that I would love to run by this community. It should allow people to add an extra meter or so to the suspension of their gymnastic rings without needing a taller ceiling -- a "virtual meter" if you will... It is a DIY solution that should be relatively easy to implement for your average handyman. I am looking for comments and feedback.
The official height for the suspension of gymnastic rings is three meters (about ten feet), but in practice virtually no private person will have a high-enough ceiling. Even in many climbing halls the anchor points in the training area are lower, despite often being located in old industrial buildings.
This can be somewhat of a problem. The rings move on the surface of a sphere with a radius equal to the strap length. The longer the straps, the less stable the rings and the more difficult the exercises. Hence the need for gymnasts to standardize the length of the straps.
The idea is to add a virtual length H to the straps by suspending the rings from a cable of length L that itself is anchored to the ceiling with two anchors a distance w apart. If the strap glides over the cable relatively frictionlessly, by means of grease or lubricants for example, it will be as if the rings are suspended from a virtual anchor a distance H above the ceiling. This figure should make clear what I mean.
However, the point connecting the strap to the cable describes an ellipse instead of the circle we need. Luckily, cable length L and anchor distance w can be geared to one another such that the ellipse well resembles the circle with the needed radius (technically, both will have equal curvature for small deviations from equilibrium). The cable length L that does the trick is given by L = w sqrt( 1 + 0.25 w[sup]2[/sup] / H[sup]2[/sup] ). In the figure a good approximation to this formula is given for those that don't have access to a scientific calculator with a square root.
Let's fill in some numbers. If we want to add an extra meter, then H = 100 cm, and if we also choose the anchor points w = 100 cm apart, then the cable length L needs to be 112 cm. For our American friends: set w to 40 inch and L to 45 inch to gain an extra H = 40 inch in height.
A few remarks:
Edit: Lots of feedback. The structural engineers seem to be worried about bending and shear forces on the anchors. So proceed with care. Many practitioners seem to think adding the extra meter is not worth the hassle as the difference in stability isn't all that big.
The official height for the suspension of gymnastic rings is three meters (about ten feet), but in practice virtually no private person will have a high-enough ceiling. Even in many climbing halls the anchor points in the training area are lower, despite often being located in old industrial buildings.
This can be somewhat of a problem. The rings move on the surface of a sphere with a radius equal to the strap length. The longer the straps, the less stable the rings and the more difficult the exercises. Hence the need for gymnasts to standardize the length of the straps.
The idea is to add a virtual length H to the straps by suspending the rings from a cable of length L that itself is anchored to the ceiling with two anchors a distance w apart. If the strap glides over the cable relatively frictionlessly, by means of grease or lubricants for example, it will be as if the rings are suspended from a virtual anchor a distance H above the ceiling. This figure should make clear what I mean.
However, the point connecting the strap to the cable describes an ellipse instead of the circle we need. Luckily, cable length L and anchor distance w can be geared to one another such that the ellipse well resembles the circle with the needed radius (technically, both will have equal curvature for small deviations from equilibrium). The cable length L that does the trick is given by L = w sqrt( 1 + 0.25 w[sup]2[/sup] / H[sup]2[/sup] ). In the figure a good approximation to this formula is given for those that don't have access to a scientific calculator with a square root.
Let's fill in some numbers. If we want to add an extra meter, then H = 100 cm, and if we also choose the anchor points w = 100 cm apart, then the cable length L needs to be 112 cm. For our American friends: set w to 40 inch and L to 45 inch to gain an extra H = 40 inch in height.
A few remarks:
- The sagging of the cable has been accounted for completely, the virtual anchor is a distance H above the ceiling, not above the lowest point of the cable.
- Has anyone heard about a similar system before? How realistic/practical do you think it is?
- This will only move the suspension upward for one direction of movement. If you're interested in improving your iron cross, for example, the cables should be installed laterally with respect to your body.
Edit: Lots of feedback. The structural engineers seem to be worried about bending and shear forces on the anchors. So proceed with care. Many practitioners seem to think adding the extra meter is not worth the hassle as the difference in stability isn't all that big.