Troubleshooting your jammed Difference Engine

*Okay: how can I not post this?

http://ed-thelen.org/bab/bab_inst.html

6. Trouble Shooting

a) Engine Jamming b) Calculation Errors c) Removal of Axes

a) Engine Jamming
1) Jamming of the phasing gear to the register pinion on the carry drive.
This is due to erratic turning of the handle or turning the handle too fast, giving rise to an over-run of the register pinion. This prevents the phasing gear from meshing at the next commencement of the intermittent drive cycle. To clear the jam a large screwdriv