Unit 2 : Final Grade Part I : Practical
Clock and Watchmaking Techniques
Candidates were required to make a carriage clock size assembly of cock, plate and squared arbor, designed to ensure that candidates can demonstrate a broad range of practical making skills. These included filing and turning brass and steel to ensure correct working fits, achieving a high standard of finish whilst maintaining required dimensions within tolerance. Where not specified the components must be finished in accordance with good practice.
Accuracy
Achieving correct end shake for the arbor again proved difficult, as in previous years. Several were a tight fit between cock and plate, while others showed excessive movement. The side shake, however, was more often correct.
Other dimensions varied in accuracy. Dimensions relating to the cock and plate were mainly within tolerance, but those relating to the arbor were less accurate, particularly the length of the squared section.
Workmanship
Turning the arbor and filing the flats was generally well done, but good, square shoulders where the flats meet the round were rarely achieved. Fitting the jewel supplied, as instructed, proved difficult. Few were flush with the top of the plate and no candidate achieved a countersink that was level with the bottom of the jewel hole.
A bevelled edge was required round the top of the cock. A number of good examples of this were seen, better than in previous years; the standard of this aspect of the work has improved. The lifting slot, however, was again given a low priority, with many left rough and unfinished.
The steady pins to locate the cock on the plate were generally neat and accurate with the pins being a close fit and the holes correctly chamfered.
Finish
A high polish with sharp external corners was achieved by many candidates but the inside surfaces of the cock and internal corners were less well finished. Abrasive marks and traces of polishing compound often remained in corners and inside holes. Screws were often well made and well polished before bluing, but the bluing itself was not generally of good quality. Candidates should be aware that bluing must be done by heat treatment, in the traditional manner. No marks are awarded for the use of blue lacquer.
Unit 4 : Final Grade Part I : The
Practical Repair of Clocks
The examination requires candidates to:-
1. Submit a Record of Repairs giving details of eight clock repairs
2. Produce a detailed drawing showing the construction of a recoil anchor escapement.
3. Design and make recoil pallets to work with an escape wheel and plate with two studs which are provided by the Institute; a maximum of eight hours is allocated for this task.
1 Record of Repairs
Each candidate submitted a Record of Repairs; all, except one, fulfilled the necessary requirements with complete documentation. It is essential that every repair has a separate form and the “Contents” form is submitted to summarise the work undertaken and confirm that the various “Repair Processes” have been completed.
2 Drawing showing construction of a
recoil anchor escapement
The weakest areas in the design drawings were the quality of the drawn lines and the quality of the lettering. Centre lines were often poorly presented; the convention requires a “chain” line beginning and finishing on a long line and, if denoting the centre of a hole, crossing on a long line. Construction lines were sometimes rather thick; they should be thin so as to easily differentiate between outlines and construction.
If candidates wish to produce hand written lettering, then lettering and numerals must be consistent in size, slope and quality; the use of a stencil or faint guidelines for lettering would much improve the quality of the work.
3 Design and make
pallets for a recoil anchor escapement
Six candidates entered this aspect of the Unit; two were of a low standard showing that candidates had not prepared adequately for the assessment.
A note about the Design
Drawing for making pallets:-
This drawing is produced in the eight hour period to enable candidates to construct the pallets accurately. There was a wide variation in the nature of the drawings which were submitted; some were detailed design drawings with every detail which might be required. This is not expected because it is essentially a basic working drawing and candidates should remember that only a small proportion of the total marks are awarded to this aspect of their work; time spent adding unnecessary details will detract from the time available to actually make the pallets. Three of the design drawings were good but two showed a lack of understanding of the method of constructing the design. Occasionally a candidate uses a different approach to that contained in the Distance Learning Course. Alternative constructions are perfectly acceptable; indeed sometimes the pallets are drawn directly on the metal. In this instance it is important that the candidate includes a drawing with notes to describe the approach; marks are awarded for the drawing.
When completed the inside and outside drop should be equal but only two examples achieved this standard; inside drop was often small but outside drop excessive. The overall shape of the pallets, which should be symmetrical with correct undercut, was often not satisfactory. The workmanship and finish achieved by the best two candidates was not good; some were very poor. A suitable finish, particularly for the pallets, requires not only a finely reflective flat surface but also the absence of underlying scratches or blemishes. Deep scratches must be eliminated before any attempt is made at polishing.
Overall
It is evident that some students had practised the exercise, a necessary step to ensure a good standard under examination conditions. The pallets account for a possible total of 85 marks and the detailed design drawing submitted with the Record of Repairs accounts for a maximum of 15%. Candidates must gain a pass level for both these areas and submit a completed Record of Repairs to achieve an overall pass.
Unit 9 : Final Grade Part I : The Practical Repair of Watches
The examination requires candidates to:-
1. Submit a Record of Repairs giving details of ten watch repairs
2. Service a quartz watch and mechanical watch movement
1 Record of Repairs
The Record of Repairs was complete in each instance and showed that a variety of work had been undertaken during the year.
2 Service a quartz
watch and mechanical watch movement
Candidates are required to identify faults that have been introduced into the two watch movements, service the movements and rectify the faults. The standard of work assessed was generally very good for both the ETA 956.112 quartz watch and the P7001 mechanical movement. All candidates gained a pass for each of the watches, a requirement for an overall pass to be awarded. Most faults were correctly identified and satisfactorily rectified.
Cleaning was generally good but there were errors in some assembled movements, e.g. the assessors found balance springs that were not flat - a fault not present when the student received the watch movements.
One weak area was the oiling of pallets; often there was an insufficient quantity or even a complete absence of oil. Examiners use a microscope to see that there is a visible wedge of oil between the pallet stone and escape wheel tooth. The application of one spot of oil onto the exit pallet is unlikely to be sufficient when it has been distributed to the acting faces of the escape wheel teeth.
The oiling of keyless work was also variable; this must be sufficient to ensure that, when distributed, all of the moving surfaces are lubricated. This should include the surface between the stem and the plate, since it performs a critical role in both lubrication and as a dust trap.
Two candidates failed to observe that one of the hands was bent so that, even though the watch continued to operate, the hand contacted the inside of the glass. Alignment of hands is an important feature in the presentation of quality work and it is important to ensure that the seconds hand aligns correctly. One candidate did not consider a date changeover at 9-15 as an error!
Candidates should include in their observed faults items such as a seriously loose screw since in a quartz watch this can lead to loss of electrical continuity and faulty operation.
Overall
A good standard had been achieved by the candidates both for
the practical test and the Record of Repairs. Candidates must achieve a pass standard for the quartz watch
and the mechanical watch movement as well as submitting a completed Record of
Repairs to gain an overall pass.
The Examiners
exercise considerable care to ensure that there can be no error in the final
mark awarded. If, however, you
believe that a mistake has occurred then you may request that your paper be
assessed again. The charge for
remarking is £40.00 per unit, which must accompany the request. This should be received on or before
31st August 2007. The
fee will be returned if it is found that as a result of the appeal process the
outcome of the examination (i.e. Pass / Fail or Pass / Pass with Merit) is
changed.
Page address http://www.bhi.co.uk/exam.htm
Last Updated 3rd August 2007