Restoration of a Two Weight Vienna Clock Movement by H. Endler ca1877

                     

This is a fine movement, made by H Endler of Silesia ca 1877. Whilst told it was running when I got it, I did not attach the weights and pendulum and see for my self. The pivot holes were very dirty and dry. The pallet impulse faces looked nasty and there was a really horrible looking Rathburn type bushing attached to the back plate.

      

        

These are particularly frowned upon in the horological community. What a terrible shame that somebody did this to this fine movement.

Why?

Given no other bushing working had been done on the movement, and given the position of the Rathburn I can only surmise that, along with discussion with likeminded friends, that it was put there to aid assembly of the strike train. In that the gathering pallet arbour’s position could be adjusted post plate assemble in order to adjust the stop position of the gathering pallet, against the rack.

It can be seen that there are 3 holes left by the Rathburn in the plate. The smallest one was for a locating pin.

  

        

I decided to ream the largest hole, taking in the smallest hole with it, and reaming the other on its own. The reamer has a slight taper, allowing the use of a slightly tapered brass plug to be cold fitted/knocked in to the plate. Given the type of movement and where the pivot hole would be in the train i.e. quite high up, I wasn’t  concerned about the friction/load of the arbour popping the brass plug. The taper tight fit would be more than enough. However when gathering pallets are re-fitted to the end of their arbour, they may need a few gentle taps to home them, with a stake. This will put pressure on any bushing on the back plate, and can pop it out. Often clock menders will shim behind the shoulders of the arbour before re-fitting a gather pallet to avoid such an event.

I cut a small chamfer on the inside of the plate, second pic above, to the newly reamed larger hole. And peened into this, pic below. In the same way I would if installing main wheel bushes on a clock plate. Excess brass was removed to original level, and the finish restored.

                 

The new hole for the gathering pallet arbour’s pivot required spotting, so using a depthing gauge the spot where the new pivot hole go should be was marked.

It was drilled using a clock plate bushing tool. The plate could be fixed flat by the tools clamps, and the 0.72mm spade end pivot drill held by the mini chuck. This ensured a perpendicular and accurate entry into the spot punch mark, and ultimately a clean pivot hole.

          

Following the hole being smoothed, a new oil sink was cut and this task was complete, second pic above. The plate restored to its original appearance.

A couple of bushes were required for a few other pivot holes, however they were in generally good order. A few pivots were a little bent, probably from previous assembly with a little heavy handedness, they were all burnished.

It was apparent somebody had previously had an attempt at re-facing the impulse pallets. At magnification you can see the file marks and the uneven finish. Personally I think they were lucky the clock was running, apparently.

            

As described in the making of Vulliamy Pallet in another entry on this blog, the pallets must re-faced as perfectly as possible. At the correct angle, and polished to a mirror finish.

A small home made jig was used to fix the verge and pallets onto the cross slide of a watchmakers lathe, ensuring that the tangent line from the brass disc (24.30mm in diameter for this verge) remains in line with the refacing surface, until the surfaces were re-faced perfectly, using different grades of wheel. And finally polish with super fine compound on a buff felt wheel. You can see the difference the right technique makes.

                             

Following a few other service related jobs and repairs the movement was assembled and ready for testing. 

Update. The movement has been on test for two weeks now and has run perfectly, so it will be going back in to its case and on the wall.

Restoration of Gustav Becker Two Weight Vienna Wall Clock

                                               

I managed to get this attractive Gustav Becker for a very reasonable price. It was the price that made my decision, had it cost too much more I may not have bothered given the work required.

The crown at the the top of the clock and bottom pediment are not original to the clock. It is not too unusual for the crown to go missing on these, less usual to have the bottom pediment missing. In the picture above right, the rear of the replacement bottom pediment can be seen. It has been well made, though with ply wood and then veneered with English Oak as had the top crown.

Below is a picture of a very similar Gustav Becker Vienna, which I used as a reference when restoring this one. The crown and the bottom pediment can be seen to be very different to the replacements found on the clock above.

As would be expected, the movement is of a very good quality. Finely made with precision, though very dirty and very oily. After disassembling it was given a thorough clean and reassembled to observe for wear in the pivot holes and the pivots. Each component is carefully inspected under magnification, looking for wear, bent teeth or any signs of metal fatigue. These finer movements often do not need a great deal of bushing work carried out on the pivot holes, however notable wear was evident and a total of 12 pivot holes were re-bushed.

                                                                          

All other aspects associated with a full service and repairs were carried out and the movement was re-assembled. Running the movement on a test stand for a couple of weeks gave the opportunity to work on the case. I wait until everything is ready for assembly before polishing the weights and the pendulum bob. After polishing these I like to coat them in a gold tinted shellac, which protects from tarnish, finger marks and gives a brighter finish.

                                                                       

Case parts were supplied by John at Old and New Times. John makes replacement components based on original designs. Having chosen the case parts it then required the task of matching the wood colours. I used small squares drawn out on a parts of the case components that would not be seen on assembly to test the colours. No two wood dyes form different manufacturers will ever be the same, so it is a case of mixing and testing in the numbered squares drawn out on the wood. It's a good idea to make notes, and use a precise measurement, such as a large plastic syringe, as you go in order to be able to repeat what you've done in a larger batch when happy with the match. It's fair to say it's pretty difficult to get an exact match, and it's a good idea to get a second and third opinion from friends. Ask them to choose the best match out of the test patches on the parts. If they agree with you it's probably close enough!

So here's how the clock looks now it has been finished. In the first picture you can see the pendulum swing with quite a large amplitude. This was reduced greatly by adjusting the locks of the pallets until the escapement wheel teeth were dropping onto the lock faces of the pallets by only approx 0.35-40mm. It now swings approx 18-19mm either side of centre, which does make it more sensitive when beat setting but is my preference to have a small amplitude. It is keeping great time. 

Tooth Repair on a Fine Clock Wheel

I thought it might be useful, and enjoyable, to show a few techniques I use when repairing/dovetailing a tooth on a French wheel. These teeth are very small and can be challenging to replace. I hope it offers something to someone.

I have used a French wheel from my parts bin.

The tooth in question can clearly seen to be bent in Pic 1.  Before the tooth is  removed, using a sharp scribe, score a line from the centre of the base of the old tooth on the radial line to centre of the wheel, no deeper than half the depth of the rim, pic 2. Once this is scribed the tooth can be carefully taken off using a very fine blade on a jewelers scroll saw; fine enough to fit between the teeth and cut along the line of the wheel circumference.

Using the scroll jaw, cut into the wheel along the scribed radial line to the desired depth, pic 3. Avoid cutting deeper than half of the depth of the wheel rim. When using a scroll saw for these micro jobs I have found the scroll saw easier to use and control if only approx a quarter of a blade is used.

Use the scroll saw to carefully cut the dovetail sides, to the same depth as the centre line already cut, pic 4. The scroll saw can be carefully used to remove any brass in the dovetail hole. Using a very thin cut of 600 grit wet and dry cloth in a ‘to and fro’ motion with both hands will effectively smooth the base of the dovetail, pic 5. Wet and dry paper will break doing this, the fiber backed type is ideal for this.

Finishing or widening the dovetail side is tricky in such a tiny space. My preference here is too use the cheap Indian suspension springs with wet and dry paper glued to one side, pic 6. This technique creates a tool that can work effectively in this small space and also will not abrade other areas of the working space, pic 7.

               

 Once you’re happy with your dovetail hole, pic 8, cut a piece of donor brass, place it under the dovetail hole, mask the wheel up with tape; holding the donor piece tight to the wheel with the tape, pic 9. Spray the dovetail very lightly with  an aerosol paint and leave to dry. Any paint on the wheel will dissolve in some acetone, and you will have the impression of the dovetail left on the donor brass, pic 10, which will be a great help when cutting the new tooth/dovetail insert with the scroll saw. Leave plenty  of brass at the large end of the donor piece for handling and holding in a vice, pic 11. It will also be a lot easier to find if you drop it, or subconsciously put it down on the bench whilst looking for a different tool.

  

The donor piece needs to be a tight fit. It is a good idea, with a very fine paint brush , to apply a little solder flux in the joint before fitting. I use Tix flux and solder.

When you are happy that it will go in with a little gentle persuasion, I have found the best way is using a staking tool and a small piece of ‘Bluetac’, pic 12, a little tap with a brass ended flat punch will fit the piece squarely. Ensure there is excess donor brass either side of the wheel, and using a steel flat punch in the staking tool, ‘peen’ the donor brass to fit/fill the dovetail hole well, pic 13. This is why the flux has already been applied in the joint.

Only very tiny chips of solder are needed for the joint, It is helpful to squash the solder in smooth nose pliers, cut teeth longways and then trim tiny pieces off and place them on the seams on the joint, pic 14. This needs doing under mag, I use 10x for this as I like to have the solder pieces ‘standing up’ as in the picture. Placing the solder in this way I find that the solder, melts, drops and flows straight into the joint and much less on the wheel rim, pic 15/16.

A mini butane soldering torch with a fine hot air nozzle attachment, to ensure there is no flame, and at a low/med heat from underneath does a great job. Some prefer other heat sources, including alcohol lamps. After it has cooled clean off any flux thoroughly.

I prefer to leave a ‘long tooth’ throughout, up until the next stage, as it is easier to see that the new tooth is still on the radial line. When cutting off the excess tooth, and filing to length it is a good idea to protect the adjacent teeth tips with tape, and keep checking it has not been breached, pic 17.

If the gaps between the new tooth and adjacent teeth has been compromised, by solder for example, it can be very tricky to ‘make good’ in such a small gap. Get another of those cheap Indian suspension springs, put it in the vice, and ‘skip’ a needle file across its edge to give it very fine teeth, pic 18. Using this will make a good job of re-defining the 90deg root angle of the tooth in the gap, where most files will not fit, pic 19.

If the new tooth is too wide, use the suspension spring with the wet and dry paper stuck to it to reduce its width. Again, using this will ensure only the width is abraded, not the gaps base. These can also be used to finely finish the tooth’s profile. Carefully remove excess brass from the tooth to match the wheel rim width, with damaging/marking the rim. The dovetail can be carefully finished/polished with very fine wet and dry paper, to a point where it is virtually invisible to the naked eye.

When using files to shape the tooth, it is best to use as fine a file as you can, cut grade 4 and above. ‘Escapement’ files are smaller than other needle files, for shaping the top of the tooth a Barette/safety escapement file is ideal. Good ones are not cheap, and should be saved for delicate jobs.

Fabricating New Vulliamy Pallets for a Vienna Regulator Clock

I'd like to thank David La Bounty for his invaluable technical advice and Ken Simmons for the use and support with his industrial size lathe to machine the original piece of tool steel. My clock maker lathes were simply not big enough to perform the original cut!

The wear on the original pallets can be clearly seen in the picture below. Ordinarily it might be possible to grind and polish the impulse faces, and refit. However I think these have had that done before now, as they are quite short, leaving little room to remove enough steel to give a clean face.  Unfortunately the existing ones are not reversible; i.e. where the pallet can be turned and fitted in the opposite verge arm, as both ends have been ground. So completely new pallets required making. This will mean that a complete ring will need to be made in order to ensure that the curvature of the nibs is as required, and the nibs then cut out of the completed ring.

In picture 1 the 60mm tool steel rod can be seem in the lathe chuck. It is quite a piece of steel given how small the pallet nibs will be. The outside diameter of the ring required is ascertained from measurements already known, i.e. the distance from the centre of the verge arbor, to the outer edge of one of the existing pallets = 51.68mm.

The inside diameter is taken from the Outside diameter minus the thickness of the pallet nib required.

= 51.68mm – 0.94mm = 50.74mm

The outside diameter is cut first and polished whilst on the lathe, not just for convenience, as the thickness of the ring can then be measured as the boring out of the internal diameter actually progresses (picture 2), using the outside finished and polished diameter as a constant, given there will be no further material removed from the outer diameter.

In picture 3  the ring can be seen to just beginning to locate in the verge. This was enough of a cut for now, as any surplus material on the internal diameter would be taken off in a polishing process.

There was a good amount of chatter when commencing parting off the ring from the steel rod, despite the tool being very sharp and central, and kept close to the tool post. So I adjusted the cutting tool to give a slightly negative cutting rake, i.e. the cutting edge was sloping downward by a degree or two. The parting tool was also ground with a slight rake across its width in order that the cutting edge (on the right edge) meant the ring parted from the rod with very clean edge. The tool adjustments made quite a difference and parting off was clean.

                   

In picture 4  the ring can be seen to be mounted in a small chuck on my Lorch 6mm lathe, the jaws have been reversed to accommodate it. However holding the ring too tightly ran the risk of distorting it, so small pieces of thick double sided tape were used to hold it in situ, whilst the jaws were minimally tightened. Round wooden dowling was used, loaded with emery paper, to polish the Internal diameter. From 600grit through to 7000grit, in stages. 

Picture 5  shows the completed ring sitting snugly in both slots in the verge. Clamping the ring between two thin pieces of wood (Picture 7) in a vice gave support for cutting lengths off to make the nibs. This ensured that the jewellers scroll blade did not ‘skip’ across its polished face, undoing all the polishing work. It also held the cut length in situ until the blade was all the way through, ensuring a very clean cut. 

           

          

Picture 6 shows the jig I made to hold the verge during the process of grinding and polishing the impulse faces on the nibs. This could  be mounted on the cross slide of my Lorch lathe. The verge must be able to ‘swing’ on a constant axis point onto the face of the grinding and polishing wheels, yet still be held firmly in order to discourage any chatter. I used a modified old centre wheel spider spring for applying tension onto the brass disc holding the verge to the aluminium plate. Hence the tension was adjustable. The brass disc was turned to have a radius of exactly half that of the measurement between the centre of the verge arbor and the dead centre of the pallet nib. This measurement meant that a tangent line from the edge of the brass disc could be aligned with the face of the grinding and polishing wheels, ensuring an impulse face of 2° would be ground/polished, picture 8 and 9. 

                                          

 Picture 11 shows the exit side pallet being ground, and the tangent line mentioned earlier. The brass wheel in picture 9 was made for sticking the emery paper onto for finer grinding and polishing. Once the brass wheel’s desired diameter was cut, its front and back was faced off on the lathe to ensure it turned square and flat to the pallet nibs impulse face. If it does not run square and true the impulse face could be ‘buffeted’ by the wheel and lead to a lesser finish. After using the grinding wheel for removing the initial amount of steel, I used cut discs of emery paper, stuck to the brass wheel with a spray glue. It does not take much glue to stick these on satisfactorily.

When using the emery paper on the brass wheel, once the face has been ground on that grade, moving the pallet nib impulse face slowly across the paper using the cross slide, whilst keeping light pressure on it with my finger, effectively removes any lines left by the paper. This is especially effective during the last polish. Grades of paper used in sequence were grits 600, 1000, 1200, 2500, 3000, 5000, 7000.

It’s a good idea to check your tangent line after changing the grade of paper, given they differ in thickness.

Pictures 10 and 12  show the finished pallet nibs, with clean edges and even impulse faces. They are hardened by heating to cherry red and quenched, followed by tempering to very light straw colour and quenched again. Followed by a final impulse face polish on the jig set up, polish of the locking face with 7000grit, and finally polished using a felt buffer and a super finish polishing compound.