Wilding Hipp Clock Toggle

[Graham ComptonParticipant @grahamcompton76871]

Rather a long time ago I made my first clock. It was the Wilding Hipp Clock, published in Model Engineer. It was my millennium clock. It has been going more-or-less continuously since then but I can't say I'm happy with the Hipp toggle action, so I'm looking for ideas/advice. The toggle and the notch were both made from hacksaw blade material, which I think was as originally described. Occasionally the toggle would would stick on the exit edge of the notch, making a loud thump. I made the spring lever that holds the notch more resilient and that improved things a bit, however, steel on steel is not a great idea and so I replaced the notch with one made from phosphorbronze. Not bad for a while, but the steel gradually cut grooves in the notch and it started to play up. I went through two versions of the phosphorbronze notch, with different exit edge geometry – no improvement. I then decided to change it all around and I've recently made a notch from silver steel and left it dead-hard. The toggle is brass. It still grabs the exit edge a lot of the time. I guess my next move will be to return to the steel hacksaw blade for the toggle, but has any one solved this problem? I've watched the mechanism in action on the tower clock in the BHI museum. Works every time, despite fairly gentle curves on the edges. Why does mine sometimes stick and that not?

regards

Graham

[Graham ComptonParticipant @grahamcompton76871]

[BizibilderParticipant @bizibilder]

There is an "improvements to the 3/4 second electric clock by J Wilding" article in ME that shows at least one resolution to this same problem in the 3/4 second electric clock which also has an Hipp trigger- the geometry of the notch is apparently not the best in the original design – this may point you in the right direction for a cure to the problem in your Hipp clock. Not sure of the volume of ME but an index search should show it soon enough.

Edited By Bizibilder on 05/05/2018 18:51:58

[Michael GilliganParticipant @michaelgilligan61133]

Graham,

You may find something useful in this earlier thread: **LINK**

http://www.model-engineer.co.uk/forums/postings.asp?th=120989

I suspect that your present problem will relate to friction in the trigger mechanism, or the geometry of the notch.

[but that doesn't really get us very far, I'm afraid]

MichaelG.

.

[Graham ComptonParticipant @grahamcompton76871]

Thanks for your comments. Since my post I've thinned down the edge of the brass toggle and it has helped a bit; it now only sticks on the edge about once in 5 or 10 (approximate, I know, but I've spent an uncomfortably long time staring at the clock; a hidden cost of infrequent pulsing). My collection of Model Engineers occupies a number of cardboard boxes in random order so finding Wilding's article on improvement will take a while!

My clock differs from Wilding's design in a number of places, mostly to reduce friction and raise the pendulum Q a bit, but the only variations that affect the toggle action are making the lever springy (I don't think that will come into play until after the the toggle has caught on the edge or not) and lightening the toggle. On thinking about it, by removing most of the brass around the toggle base and therefore shifting the toggle's centre of gravity away from the pivot I will have lowered the frequency of it's swing and slowed it's movement away from the the edge of the notch. However, a bit of blue-tack at the base doesn't seem to have made any improvement.

If all else fails, I may try adding a light spring to the toggle.

regards

Graham

[Michael GilliganParticipant @michaelgilligan61133]

Graham,

I feel the need to tread very carefully [*] so I will offer just one link that you may find useful:

**LINK** http://www.hvtesla.com/masters/po36_intro.html

That page nicely illustrates the Agate notch-block on the GPO clock, and includes links to a descriptive page: There are many variations on Hipp's elegant theme, but I think this version is particularly 'well engineered'.

… It would be interesting to see some photos or sketches of your toggle mechanism, so that forum might discuss.

MichaelG.

.

.

[*] "Once bitten — twice shy"

When I posted links to some explanatory animations of a clock mechanism for someone last year, I obviously did the wrong thing, and caused offence. …. That's a situation I would never wish to repeat.

Edited By Michael Gilligan on 07/05/2018 08:20:00

[Roger HartParticipant @rogerhart88496]

Many years ago I looked after clocks in a telephone exchange, just like the one pictured above. The maintenance schedule advised that the Hipp clock be oiled once in a blue moon. In my youthful enthusiasm I decided it was about time, older hands advised 'leave the b%&*dy thing alone'. I spent the next couple of months resetting clocks and trying to get the thing back into time, the old hands were right!

FWIW the toggle was steel and pivoted very freely.

[BazyleParticipant @bazyle]

It seems to me that the difference in amplitude between swings as measured at the "exit edge" is going to be in the order of a few thou. If the interface of this edge is rounded to a greater extent than this amount the toggle will not be able to drop away precisely at the same decay point. This will be made worse if the toggle is rounded too and if the toggle twists on its bearing. Wear in the bearing might therefore be a cause of loss of performance after a time.

[Graham ComptonParticipant @grahamcompton76871]

I'm envious of that agate notch-block. Before I made my steel version I was contemplating some sort of jewelling, but I decided that it would take me too long to master the technique. I'll try to get a picture of mine, but my macro photos never look very good. The differences in shape from the agate version are: the notch is a right angle whereas the agate one looks rather more than 90 degrees; my entrance ramp is linear rather than a curve; my exit edge is another right angle – this is the most interesting difference, the agate version clearly has a flat top. I'll try that on my next version.

Yes, the decay between swings measured at that exit edge is going to be very small. I wish I could think of a non-invasive way of measuring the pendulum position, but I've yet to think of one, especially one with that sort of resolution.

Yes, leaving it alone might have been the best advice. The clock was working reasonably well until my wife wanted it off the wall to make way for decorating. While it's off the wall, I thought, I'll just have another go….

The slightly mysterious good news is that over the last 24 hours the proportion of impulses where the toggle sticks has gone right down, not to zero, but probably now only once an hour. I can think of only two explanations: the steel edge has trimmed off some of the brass toggle and improved its shape or the draining battery has changed the magnitude of the impulse to a level where, by chance, the decaying swing doesn't hit the edge but drops neatly on either side. Time will tell, but one reason I swapped the materials was that the steel toggle was cutting grooves in the notch block, making the sticking worse, the new hard steel version should avoid that, but possibly at the expense of the brass toggle.

regards

Graham

[Michael GilliganParticipant @michaelgilligan61133]

Graham,

At the risk of diverting you, away from solving the problem with your existing toggle mechanism:

May I share this little gem of a video: **LINK**

The 'inverted' design is an interesting option

MichaelG.

.

Edit: New York Standard Watch Company

http://www.pocketwatchrepair.com/histories/nys.html

http://www.rareclock.clockdoc.org/_wsn/page16.html

Edited By Michael Gilligan on 08/05/2018 07:00:30

Edited By Michael Gilligan on 08/05/2018 07:05:31

[Stephen BensonParticipant @stephenbenson75261]

Hipp toggle is on my todo list however I have no idea how to get email notifications other than by posting on thread

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Stephen Benson on 08/05/2018 08:20:15:

… I have no idea how to get email notifications other than by posting on thread

.

It's not a facility that I use, but there is a 'Bookmark this thread' link [at the bottom of this column]. … Only visible when logged-in.

MichaelG.

Edited By Michael Gilligan on 08/05/2018 08:36:42

[Graham ComptonParticipant @grahamcompton76871]

My daughter tells me that this is a link to a picture of my toggle mechanism:

**LINK**

I tried clicking on the likely looking icons but couldn't work out how to post an image using the tools on the forum page. Not intuitive for me I'm afraid.

Meanwhile, she also lost all my text so here we go for the second time.

I feel a bit of a fraud. The toggle mechanism has healed itself and in a few days it has gone from sticking every other impulse to not sticking at all for the last 6 hours while I've been monitoring it. It remains to be seen whether this is permanent. One reason for using a hard notch block was that any material removed might make things better rather than worse – but it might be luck.

Assuming the image is available: It's fairly self explanatory. The notch block is a corner of 3/16" silver steel, milled to clean up the edges and add a 90 degree notch. Polished in the immediate vicinity of the notch. Tapped 3mm and then coated with soft soap, heated and quenched in brine with some oil on top. The lever is a piece of clock spring, a hole punched in the middle for the block. There is a shorter piece of spring below it that extends a bit less then half way from the mounting and another shorter piece between the main piece of spring and the block to change the way it bends. The contact is at the left end. The toggle is a bit of brass sheet (not engraving), soldered to a brass tube drilled 1/16" for the arbor. Brass hammered to harden and filed to thin the edge. In the image, the pendulum is moving left to right.

fingers crossed

Graham

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Graham Compton on 08/05/2018 22:39:37:

My daughter tells me that this is a link to a picture of my toggle mechanism:

**LINK**

I tried clicking on the likely looking icons but couldn't work out how to post an image using the tools on the forum page. Not intuitive for me I'm afraid.

.

The link is fine, Graham … please give your daughter my thanks.

Meanwhile; here is the essential guidance on posting photos: **LINK**

http://www.model-engineer.co.uk/forums/postings.asp?th=103028&p=1

MichaelG.

[Graham ComptonParticipant @grahamcompton76871]

Thanks Michael. Sorry, "if all else fails, read the instructions". I'll try your instructions to show a wider view of my version of the Wilding Hipp clock switch mechanism.

Thanks for the link to that Hipp clock on Youtube. Rather more elegant than mine, although part of my excuse is that I've tried to minimise the weight of moving parts. My first notch blocks were very much lighter than the one at issue, which was born of desperation. I think my criticism of the Wilding design, viewed from where I am now, is that some of the moving parts are a bit massive.

The image was taken with a Lumix on the widest angle, so the perspective is a little odd. The arrangement of the pieces of spring in the lever may be visible, although as I'm typing this it looks as though the resolution has been reduced. The observant may notice the BlueTac preventing the screw on the left from moving.

The notch is offset to the left by rather more than I intended (yes, I should have measured more carefully) and the result is that the pendulum arc is quite large. However, it works! And without sticking for a good day and a half now, so I'm loathe to interfere. As a watch repairer said to me when I'd managed to re-assemble my wristwatch "quit while you're ahead". Maybe next time it comes off the wall for the decorating. Or sooner if the large swing continues to offends me.

regards

Graham

[Graham ComptonParticipant @grahamcompton76871]

There's the god news and there's the bad news:

The clock has only made one loud noise (in my hearing) in the last few days. All other switching events have been quiet. So it sounds as if the toggle no longer sticks on the edge of the notch block.

However, I connected a 'scope across the solenoid. The pulse is generally about 130ms with most events between 110 and 150ms. Occasionally though there are 300ms events. I recorded two of these and I was watching the second. The toggle caught on the exit edge and so pushed spring lever further down and closed the contacts for longer. It was quiet because the toggle didn't slip off.

So, the noise is cured, but not the fault. Has anyone out there made similar measurements on a Hipp toggle?

regards

Graham

[Paul StaniforthParticipant @paulstaniforth17543]

Hullo all,

I am no engineer but came across your correspondence today when researching this clock mechanism. I am currently at West Dean College of Art & Technology in Sussex where hanging on the wall is a functioning Higgs toggle clock made by students in the 1980s. It’s based on instructions found in a very early Model Engineering magazine. The clock was made in the clock making workshop which has been taking students for years and for which the college is famous. If it’s of any help I believe part of the toggle mechanism is made of the non conducting stone Agate.

I cannot contribute any more and will be leaving the college after my short course (nothing to do with clocks) in 2 days.

Good luck to all you model engineers. Paul

[Tony JeffreeParticipant @tonyjeffree56510]

Posted by Graham Compton on 05/05/2018 17:41:19:

Why does mine sometimes stick and that not?

Rather late in the day coming across this…but my 2 pennorth:

I suspect what you are seeing is an inherent problem with the Hipp toggle – unless everything is precisely aligned, the trigger and notch are perfectly hard and have very sharp edges, there is always the possibility of the trigger "catching" on the edge of the notch rather than in the base of the notch as it is supposed to do. My version of the Wilding 3/4-second pendulum clock has always exhibited this behaviour, and I pretty much gave up on fixing it; the clock keeps good enough time so I ignore it. However, that is one of the reasons that eventually led me to build a pendulum with a similar drive mechanism but which uses Hall-effect sensors to detect the pendulum swing amplitude, which removes the problem altogether – see link. I am tempted to retro-fit a similar solution to the Wilding clock at some point.

[Martin KyteParticipant @martinkyte99762]

Regarding the original post. Not entirely sure the steel on steel aversion is relevent. Fair comment regaring bearing surfaces but in the toggle the action is either batting the lever out of the way or sliding into the notch with very low friction. I would be interested to know if the toggle block or lever or both become magnetised to any extent. I can see that messing things up and creating unexplained issues that dissapear after a while.

regards Martin

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