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Old 09-23-2016, 04:09 AM
Danny B Danny B is online now
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Join Date: Oct 2012
Location: L.A. Ca.
Posts: 3,181
Offset pivot

That's quite an expensive machine that you have built. AND, quite dangerous. I certainly wouldn't go to 100 rpm.,,, especially with just one connection and a chain on the lower weight.
Earlier, I wrote; "The upper pivot point for the drive could be offset from the center of the gimbal." Apparently, you have offset the lower pivot point rather than the upper. (5 cm.)
Was there any reason that you moved the pivot of the lower weight rather than the upper weight?
I'm doing load testing now. It takes about 30 watts, DC to rotate 150 kg. at 60 rpm.
The reason that I ask about you moving the lower pivot as opposed to the upper pivot is; all 4 lower weights MUST be locked together to do actual drive work. All 4 weights MUST be synchronized to keep the machine from shaking apart. If you lock them together, how is any one weight going to free-fall on the downhill stroke?

On my build, The arm that drives the upper shaft only positions the shaft. It does not drive it in rotation. The upper shaft is free to rotate or not. After my initial load testing, I'll move the upper pivot off-center. I expect the rotation of the shaft to "retard" on the uphill and "advance" on the downhill.
It remains to be see just how much of this variable speed can be imposed on the lower weights if the 4 shafts are locked together.
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