*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
- 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 screwdriver is required to rotate the register pinion anti-clockwise, thus releasing the jam. The Engine will continue with no loss of calculation numbers or error induction.
Jamming due to the figure wheel locks striking the tops of the figure wheel teeth
OR the sectors failing to mesh with the figure wheels
This is due to erratic turning of the handle or turning the handle too slowly. Either the lock jams by striking the figure wheel teeth which has failed to fully rotate or the sectors have rested on the top of the figure wheel teeth due to one or the other failing to fully rotate. The error in rotation is only one to two degrees and is generally due to the lack of momentum to complete the rotation and engage. To clear the Jam establish which reason has caused the problem. To check the figure wheel locks, try lifting them at the bottom link. If they are free there will be a small amount of movement. If one has jammed it will feel solid. To clear the jam, remove the shoulder screw and washer at the bottom of the lock and lift the lock up. Check the columns of figure wheels to see which one has been slightly displaced. Turn the displaced wheel to align the number to the arrow. Do not over-rotate the wheel otherwise the wrong number will be set up and an error created in the calculation. Lower the lock and check that it now engages into the figure wheel teeth. Re-connect the shoulder screw and washer. Re-check all the figure wheel locks again before attempting to turn the handle. To check the sector/figure wheel mesh, try pulling down each column of sectors. If they are free there will be some movement. If one has jammed it will be solid. To clear the jam, move each sector on the column until you find' the one that is solid due to resting on the figure wheel. Using a large screwdriver, lever up the column of sectors enough to take the load and free the sector/wheel mesh. Release the column of sectors and pull down on the top to check there is now movement. Repeat the procedure if still solid, as there may be more than one sector involved. Re-check all the other sector columns. With care the jam can be cleared without interrupting the calculation cycle and the calculation continued without errors.
Jamming due to sectors catching the sector zero stop
Carry out the same procedure as (11) except you are now looking at the sector/zero stop relationship. If this jam cannot be cleared you may have to remove the sector zero stop to free the jam and then return the stop back to it's original position. To remove the sector zero stop, remove the two screws on the top bearing plate and the two screws in the bottom bearing plate that holds the stop. Again there should be no interruption of the calculation cycle.
b) Calculation Errors
Errors In calculation are either due to the Operator setting the wrong coefficients on to the figure wheels (see Section 3) or a carry lever that has failed to operate correctly.
When the Engine is moved to a new site it is suggested that the calculation of y = x' from x = -80 to x = +80 be carried out to check the accuracy of operation. If the Engine is being used on a regular basis this check should be carried out at the start of every week. If there is an error in the calculation then the Engine should be set up to carry out two sets of calculations simultaneously. Calculate y = x from x = -80 to +80 as before. With x = -80 or +80 the result has only fourteen significant figures. Therefore the two calculations can be set one above the other, y = x' across the axes using wheels 1 to 14, y = x using wheels 15 to 28 and setting the counter on wheels 29 to 31. The results can be compared and checked to see if they are correct after each calculation. If one answer is wrong, then the coefficients at that setting can be compared with those of the other equation. By this means you can identify which carry has failed to function. That carry lever can then be adjusted using the tool provided and the operation repeated. This procedure is repeated until the full set of calculations has been carried out without error. (N.B. Care must be taken not to overstress the carry levers when adjusting otherwise the solder joint of the lever will break.) ...
