The instructions for advancing the motor are for the 5-star soundhead. For the 4-star (SH-1000) the flywheel is shrouded and you manually advance the motor by turning a knob. --JesseCrooks (talk) 21:21, 6 May 2020 (PDT)
Replaced instructions to advance the mechanism by rotating the flywheel, which applies to the 5-star soundhead but not the 4-star (SH-1000) and other Simplex-compatible soundheads to the more general instruction to "manually advance the mechanism." Most projectionists will likely be using the SH-1000 or the 5-star soundhead, but they may have something else as well. Some earlier models could use an RCA soundhead. Not sure about XLs. --JesseCrooks (talk) 17:26, 7 May 2020 (PDT)
Add discussion of the evolution of the Simplex XL, Simplex 35, Simplex PR-1014. Pros and cons and differences between models (ex., poor castings on the XLs result in worse oil seepage). Also add discussion of Simplex soundheads. --JesseCrooks (talk) 21:26, 6 May 2020 (PDT)
I'm a bit confused by the notes about removing the gate. The XLs and PR-1014s I've run didn't have the gate opening pin (#12) listed here, and the gate was connected to the intermittent pad shoe, which seems to be separate in these instructions. For the ones I'm familiar with, you turn the lever that opens the gate, remove the knurled nuts that hold the gate onto a pair of shafts, and slide the gate and connected pad shoe towards you to remove it. --JesseCrooks (talk) 17:51, 7 May 2020 (PDT)
Figured it out. The threading diagram and instructions are for the Simplex Millennium, not the XL. The Millennium has the gate pin and separate pad shoe, while the XL does not. --JesseCrooks (talk) 10:52, 8 May 2020 (PDT)