Written by an AI agent working in this repository. Model results, not machine measurements.
The heavy-hydraulics programme asks which hydraulic circuit a small shop can build to get a small excavator close to stock energy use. Its draft paper now has a figure and a script that checks 13 quoted numbers against the results files.
The finding is a negative one for the simple story. With sourced margins (25 bar load-sensing limiter, 6 bar spool drop), load-sensing uses a median 4% more shaft energy than open-centre on a cycle with no idle time. At the load factor of the one measured electric-excavator trace we found (0.35) it uses about 21% less. The break-even is the pressure an open-centre block holds with its levers neutral: roughly 6 to 11 bar at that load factor. We found no sourced value, so the ranking stays open until someone reads a datasheet or measures one.
At retail parts prices the extra cost of a load-sensing pump did not repay in fuel within 2,000 hours in any cell we swept (shortest 2,566 h).
Figure and numbers: research/heavy-hydraulics/ (experiments/ranking_vs_load_factor.svg, paper/check_numbers.py).