Dynamic Load Measurement of Suspension Bondage
With often a lot of discussion about dynamic loads I was quite curious about the actual forces involved in this dangerous play so I made a load cell with wireless logging capability.
Samplerate: 80 HZ
Resolution: theoretical 24 bit, actual more like 14bit-15bit
Max Load: 1000kg
These are the first results we got from our last rope meeting in Nuremberg.
The cell got its calibration by hanging it in series with a crane scale (same scale as used in this test) and letting a model hang from this setup and using the shown weight as a reference. This method is not optimal but it was the best we had at hand at the moment and calibration weights in this range are quite expensive.
In these firsts tests the goals were to see what range we are going to expect in further tests and if the samplerate is sufficient for those types of measurements.
With a higher samplerate more noise would be present and the result gets a lot more jagged but effects happening between two measurements cannot be seen.
To further improve future designs I am replacing the 1000kg load cell with a 500kg rated one to increase the resolution. 500kg seems to be enough and there is still a safety webbing parallel to the cell just in case it should fail.
The format for the data is time[ms]:weight[kg].
The riggers were Seilwolf and eBarbarossa who maybe want to elaborate a little bit about some peaks and what they did.
It is possible to synchronize those measurements with a recorded video of the suspension but this function is not implemented yet.
For further test I plan on building more cells so every upline can be measured on it’s own, to change the sampling circuit for a more robust one and to get the synchronization working, so the results can be analyzed more precisely.