John Wilding Regulator

Adding extra weight will lead to more friction hence wear on pivots I would make sure that the pivots and pivot holes are dead smooth and polished and not too tight mine is about 25 years old and runs on about 6 lbs ( if I remember ) and keeps time dependant on temperature because my Invar pendulum rod is not stable

Roy

Many thanks Roy, I half wondered that, hence the question.

I finished all the pivot holes using pivot burnishers and made a flat pivot burnisher from a small file withe the teeth linished off so that the grain of the linishing did the polishing.

I'll try removing some weight.

Edited By Brian Hutchings on 31/01/2016 12:56:06

I don't seem to be able to get much workshop time these days with all the other pressures on my time. It's nearly a year since I poste my last update so it's time for another.

About a year ago I had the movement test running propped up on some bricks on a Workmate. My next task was to make a dial. I drew up the dial in reverse on Draftsight and printed it out on Xerox transparent film in two parts as it is too big for my A4 ink jet printer. I found the inkjet printer in photo mode gave a better result than my laser printer. The two parts were lined up using printed registration marks and cut and joined. I then laminated some dry film photoresist onto a sheet of brass using an office laminator and and exposed the resist to UV from the sun for three seconds (not having a light box) . After developing I had this:

I then silvered the dial using silvering powder from Honiton Clocks and lacquered it with shellac. All the above required numerous experiments to get the process right.

Then it was just making the hands. I intended to use my little cnc mill to cut them out but a computer failure occurred and I ended up making them by hand the traditional way. I don't think the result was too bad:

The clock is now running and mounted on the dining room wall while I continue with the case:

I had to get the hardwood for the case shipped over from the UK ans I couldn't find a supplier here other than complete trees sawn into planks. Anyway, the case is now ready for varnishing:

Not much left to do now

Russell.

That's looking rather fine, Russell

MichaelG.

That looks very good Russsell. Glad to hear that the photoresist can be exposed in the sun. I've done that with pcb's so wondered.

Tempted to mention types of ball bearings but I think I will put it in the beginners clock thread.

John

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NIce work, Russell.

Neil

Russell Well done

Roy

Hi Roy,

That is a truly beautiful clock and dial and case! Wonderful work!

How did the dial surround/rim change from 'silver' to brass?

Will you add a brass sleeve to the pendulum bob?

What wood did you use for the case?

Cheers,

Julian

"How did the dial surround/rim change from 'silver' to brass?"

Poor lighting, almost backlit from a window in sunshine!

"Will you add a brass sleeve to the pendulum bob?"

A nice idea but I will have to consider the effect on temperature compensation.

"What wood did you use for the case?"

I managed to find some sapele faced plywood locally for the panels and then ordered sawn sapele from Robbins Timber in the UK. I still have a homemade router table that I made for doing boat repairs many years ago so was able to use that to make the mouldings fairly easily.

Russell

Lovely work and and I would also like to know more about how you printed the dial

Russell

That is beautiful work throughout - something to look at everyday and get pleasure from.

BUT....."the case is now ready for varnishing:"

Please don't VARNISH it! Instead take the time to apply successive coats of button polish, with a rubber, to build up that lovely deep, smooth, shine.

I can imagine many restful hours in the company of your clock as it plays you its peaceful and comforting song!

 ......of course what are you going to do with your spare time now ?

Norman

Edited By NJH on 29/04/2016 12:11:11

O.K. here goes:

I started by drawing the dial using Draftsight although any 2D CAD system would have done. I then mirrored it to get a reversed print so that the printing on the transparency would be on the underside and directly in contact with the resist. I found that the printer would not print to the defined pen thicknesses so I printe to PDF and then used the PDF viewer to print the master on acetate film using an Epson printer in photo mode in order to get dense blacks.

I thoroughly washed the brass sheet in detergent and hot water to remove any grease and then wet laminated the resist film before passing it through an office laminator. The brass with the photoresist and the master was then sandwiched between an MDF board and a glass sheet with some thin translucent plastic foam to make sure there were no gaps between the brass plate and the master and expose to the sun for 3 seconds. I am in the South of France so I guess slightly longer exposure would be needed in the UK. The resist film came from Mungolux in Germany.

Once exposed the resist was developed in washing soda solution and then washed to give the result shown in my photo. Exposure and development times need to be determined by experiment.

The plate was then etched in ferric chloride for about an hour with occasional agitation. Then washed and dunked in caustic soda solution to remove the resist.

I sprayed it with black acrylic car paint to fill the etched portions and the paint on the unetched parts was removed using fine wet and dry paper and water. I then grained it with 240 wet and dry, fairly coarse but it looks appropriate on a large dial.

Again very careful washing before rubbing with silvering powder and then finishing powder. To protect the silvering I made up a lacquer from shellac dissolved in colourless meths (sold here as burning alcohol).

Throughout I did experiments on scraps of brass to verify each process. I now see why bespoke etched dials are so expensive to buy!

Russell

Yes, french polish is very nice but I have never had much success with it. I am using several thin coats of a good quality satin finish varnish (Liberon) and will wax over it. Certainly none of the modern water base varnishes.

Russell.

Three days might do it.

Neil

Finished at last:

Russell.

Lovely job, Russell

MichaelG.

John

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My clock has now been running for over 8 months and after some teething troubles is giving quite good timing. Over the month of December it gained just over one second which is quite pleasing. The following is a plot of the going rate daily change over the month of December:

The green line shows my actual measured values using a stop-watch to compare with an atomic clock app on my tablet. The greater part of the random variation is probably due to my measurement technique.

The black line is a moving four day average to smooth things out and clearly shows an increasing rate, increasing by about 0.25 second/day over the month. My initial thought is that the friction in the clock is slowly reducing with running in.

Now comes my problem in understanding:

Intuitively I would expect reducing friction to speed things up. However reduced friction must result in a greater swing of the pendulum and that should result in a slower rate due to the circular error of the pendulum. So which is right?

Russell.

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Forgive me, Russell ... I have probably missed something significant; but I can't reconcile those two statements.

Could you please clarify ?

Many thanks

MichaelG.