Q5. Calendar Work. (2 attempts) This question was not well answered. Descriptions were lacking in detail and sketches were poorly proportioned; the engagement of fingers, wheels and jumpers was often inaccurate.
Q6 Self-winding Watch. (5 attempts) This was generally well answered. Both the reverser wheel and rocking arm systems were well described and well understood. Supportive sketches clearly illustrated the action of the parts.
Q7 Lever Escapement errors. (8 attempts) Candidates had to explain poising, curb pin, escapement, temperature and centrifugal errors. Apart from curb pin error, which was well understood, there was limited understanding of the principles. Candidates struggled with this question with only two scoring above half marks.
Q8 Cylinder Escapement. (8 attempts) This was the best answered question on the paper with many candidates scoring very high marks. The action of the escapement and the construction of its component parts were well known and understood and well described, with good illustrative sketches. In some cases an amount of historical information, not asked for in the question, was included. Extra marks cannot be awarded for material that does not answer the question, even if it is correct.
Section
B - Short Answers. Many high marks were scored on this
section. The questions least well answered were; the main purpose of stop work
in a fusee watch (Q19) and, "What is a depth tool most commonly used
for?" (Q24). Several questions were answered correctly by all ten
candidates.
Unit 10 : Final Grade Part II : The
Practical Repair of Watches
The examination
requires candidates to:-
1.
Submit
a Record of Repairs giving details of ten watch repairs
2.
Service
an automatic watch and a stopwatch movement.
1 Record of Repairs
Candidates are required to service fifteen watches for their Record of Repairs. Each Record of Repairs was complete and showed that a variety of work had been undertaken during the year.
2 Service an automatic watch
Four faults in each which had been introduced for the purpose of the assessment; candidate are expected to identify and correct the faults and service the watch and watch movement. The watches were an ETA 2893-2, a gents automatic with date and centre seconds hand, and an uncased BFG 411 stop watch.
The standard of work on the automatic was generally good; the cleanliness of the watches was also good but there was minor damage to screw heads and slight general damage.
The alignment of the hands at 12 o’clock was generally satisfactory but a significant failing was that hands had been installed which were not parallel to the dial; there was the consequent risk of hands fouling. This is a most important part of the presentation of a finished ‘service’. The service manual provides exact heights for each of the hands and these can be achieved with the jewelling press or similar.
Oiling is a key area and was generally completed to a good standard on balance staff endstones; the pallet faces showed, in contrast, extraneous oil. Another error was the lubrication of the stop lever, part 9433; this should not be oiled since the oil could migrate to unwanted areas. Automatic work was correctly assembled and operative but oiling was often excessive.
Fault finding with appropriate corrective action was generally very good. There was generally a good amplitude for the balance but the balance springs in some watches were not exactly flat.
3 Service a stopwatch movement.
Candidates were required to find four faults in a BFG 411 stop watch movement complete with dial and hands, service the movement and rectify the faults. This movement provides a very different test from the ETA 2893 automatic on which all candidates performed well. A stop watch has a number of different mechanisms each of which has to function and be adequately lubricated if it is to perform satisfactorily.
There is a brake on both the balance and seconds wheel; these are important and a key feature of a rapid stop which is essential for an accurate indication on the dial. Setting of hands exactly to zero after reset is essential and was not always to a high enough standard.
Balance springs were not generally sufficiently flat or central, sometimes due to poor pinning at the stud, surprising on a watch of such a large calibre.
Lubrication for a pin pallet watch of this size does require care since the pallet pins are a potential problem area. An oil should be used which will remain in place; Moebius 9010 may be satisfactory on smaller calibres but is totally unsatisfactory in this instance; 941 should be used. All of the sliding levers need to be adequately greased but not such that these may be transferred to other areas. Transfer to small pivots or balance springs can cause loss of power and performance.
Overall
The candidates achieved a good standard for both for the
practical test and the Record of Repairs.
In order to gain an overall pass, a pass standard for the automatic
watch and the stopwatch movement must be achieved as well as submitting a
completed Record of Repairs.
Unit 11 : Final Grade Part II : The
Theory of Watches and Watch Restoration and Conservation
There were five candidates for this paper. One candidate only attempted three questions rather than the four required.
Q1
Marine Chronometer. (5 attempts) The drawing and
description of the action were generally of a good standard showing an
excellent understanding of the spring detent escapement. The description of the
safety action was, however, less well answered, with several important points
omitted.
Q2 Early forms of Keyless Work. (5 attempts) There were good drawings and descriptions for both the Rocking Bar and Sliding Sleeve type of keyless work. Candidates were clearly familiar with both mechanisms and scored well.
Q3
Perpetual Calendar work. (4 attempts) This is a complicated mechanism to
describe, but all four attempts were successful in varying degrees. The design
of the month cam and mechanism for automatic correction of short months was
well known with adequate descriptions. Diagrams were often not well proportioned,
but adequate for the purpose.
Q4 Equation work / missing wheel & pinion. (1 attempt) The candidate attempting this question produced a very good answer. The drawing showed an equation cam of appropriate shape and the correct use of a rack and pinion to amplify the movement of the follower. The required numbers of 13 and 6 for the missing escape wheel and pinion were correctly calculated from the given tooth count.
Q5 Elasticity & Mainspring calculations. (4 attempts) This was the least well answered question. Hooke's Law, Young's Modulus and Moment of Elasticity were not accurately defined in most cases. The calculation of the limiting radius was often correct, but further calculations to find the maximum number of turns and optimum length contained errors. Most were aware of one or two reasons for the difference between theory and practice, but few could list all four.
Short
Answers. This section was well answered, in
general, and, apart from the astronomical section, showed a good all round
knowledge of the syllabus. The two questions relating to astronomical work,
i.e. explanations of the leap second and sidereal day were, in all cases,
either answered incorrectly or omitted.
Unit 12 : Final Grade Part II : Practical
Watchmaking Techniques
The syllabus requires candidates to be able to make small watch components. The examinations focused on a range of different types of components and candidates ably met the challenge. The requirement this year - make a balance staff for a platform escapement, a stem and an index ring complete with boot and index pin for a UT 6497 pocket watch movement.
Six candidates entered this Unit and all achieved a satisfactory standard with four good pieces; one candidate gained a Pas with Merit.
Care should be exercised when removing the balance spring to avoid damage to the collet, the balance or the balance spring. In one instance the collet had become distorted so that it was no longer a friction fit on the balance staff; marks were lost for this defect. Similarly a suitable fit must be achieved for the roller. The balance staff was generally well made, the pivots were, in some instances, well made but many were rather flat at the end. One had excessive end play and for one the balance was out of flat due to poor seating. Finished pieces are checked by examiners for poise and neat accurate seating is necessary to ensure that the balance is flat. Any gaps between the balance and its seating on the staff will result in the balance wobbling as it oscillates. Accuracy is essential to achieve a satisfactory poise. Neat true seating of the roller is also required and was usually achieved.
The stem was well made and each one functioned well in the watch although some were loose between the plate and barrel bridge. The threads were satisfactory but to achieve full marks it is important to ensure the thread is uniform and not torn.
Finishing of the stem, particularly the square and the pivots, was very variable, some were very good. These items provide an opportunity for candidates to demonstrate their skills at achieving a first class finish on flat and rounded surfaces.
Finishing was also the major failure on the boot and index
pin. There had been little attempt to give these items any neat finish or
polishing even though a polished finish was requested. (These items would not necessarily
have a fine polish, just a smooth grained finish but the question papers
requests candidates to ensure the parts are “finished to
a high standard”. Finishing was often good on the top index surface but
with edges rounded marring the outcome and there was little attempt to smooth
and polish the edges of the index ring.
Riveting was safe with correct friction on the boot action but could be neater in some cases with the two rivets matching. It is not essential for the rivets to be finished flush with the index, a help when avoiding damage to the index top surface.
Unit 8 / 13 : Final Grade Part II : The
Practical Restoration / Conservation of Clocks / Watches
More detailed requirements were provided at the start of the year to give clear guidance to candidates on how to set out their work under four separate and distinct headings.
a. Appraisal
b. The Conservation /
Restoration Process
c. A Justification of the Conservation / Restoration Approach
d. Research
An example was also provided to enable candidates to emphasise the kind of approach and content that is required.
Six portfolios were assessed, one clock and five watch.
All candidates laid out their work in the four sections required by the guidance notes and the standard of presentation was generally good. The quantity of material was as required and excessive material was not submitted. This helped with assessing the work.
There were two very good portfolios, one clock and one watch, but the latter not reach Pass with Merit standard. These were the only candidates who had studied the BHI document ‘Servicing of Clocks and Watches’ sufficiently carefully to adequately justify their approach. Most candidates had attempted to demonstrate an understanding of the principles of conservation/ restoration but without the background information presented in the ‘Servicing of Clocks and Watches’ it was often unconvincing.
Many items lacked a full description of the pre-repair condition.
Choice of suitable materials is often discussed when making of watch or clock parts but usually without any justification of the resulting strength and application of the part.
In the Research section only one candidate provided a list of source references. No one made reference to the BHI document ‘Servicing of Clocks and Watches’. A list of references is a fundamental part of demonstrating that the research is sound.
Use of photographs was generally satisfactory but there were few diagrams.
It ought to be standard practice to give part numbers when relating to watch part spares, since this can be important in ordering spares from suppliers, but only one candidate did so.
Some candidates made components which showed clear signs of being hand made without any of the neat professional finish to be expected on watch parts. However, some novel approaches were noted, such as, making a rubbed in jewel by rounding the edges of a press fit jewel to provide a jewel of correct thickness.
If a candidate uses “modern” watches for each item in the Portfolio, the opportunity for restoration, the making of components, can be limited.
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