• Important Executive Director Announcement from the NAWCC

    The NAWCC Board of Directors is pleased to announce that Mr. Rory McEvoy has been named Executive Director of the NAWCC. Rory is an internationally renowned horological scholar and comes to the NAWCC with strong credentials that solidly align with our education, fundraising, and membership growth objectives. He has a postgraduate degree in the conservation and restoration of antique clocks from West Dean College, and throughout his career, he has had the opportunity to handle some of the world’s most important horological artifacts, including longitude timekeepers by Harrison, Kendall, and Mudge.

    Rory formerly worked as Curator of Horology at the Royal Observatory, Greenwich, where his role included day-to-day management of research and digitization projects, writing, public speaking, conservation, convening conferences, exhibition work, and development of acquisition/disposal and collection care policies. In addition, he has worked as a horological specialist at Bonhams in London, where he cataloged and handled many rare timepieces and built important relationships with collectors, buyers, and sellers. Most recently, Rory has used his talents to share his love of horology at the university level by teaching horological theory, history, and the practical repair and making of clocks and watches at Birmingham City University.

    Rory is a British citizen and currently resides in the UK. Pre-COVID-19, Rory and his wife, Kaai, visited HQ in Columbia, Pennsylvania, where they met with staff, spent time in the Museum and Library & Research Center, and toured the area. Rory and Kaai will be relocating to the area as soon as the immigration challenges and travel restrictions due to COVID-19 permit.

    Some of you may already be familiar with Rory as he is also a well-known author and lecturer. His recent publications include the book Harrison Decoded: Towards a Perfect Pendulum Clock, which he edited with Jonathan Betts, and the article “George Graham and the Orrery” in the journal Nuncius.

    Until Rory’s relocation to the United States is complete, he will be working closely with an on-boarding team assembled by the NAWCC Board of Directors to introduce him to the opportunities and challenges before us and to ensure a smooth transition. Rory will be participating in strategic and financial planning immediately, which will allow him to hit the ground running when he arrives in Columbia

    You can read more about Rory McEvoy and this exciting announcement in the upcoming March/April issue of the Watch & Clock Bulletin.

    Please join the entire Board and staff in welcoming Rory to the NAWCC community.

American Barr/Poole hip toggle adjustment ? Help

cvcman

Registered User
Dec 15, 2011
45
0
0
I have 2 Barr clocks, I just made new contacts for the one,,,it runs and keeps time but a couple questions

1) it seems to cycle every 20 seconds, how to I increase that ?

2) how do you properly adjust the contact screws ? I have them so they both touch at the same time but what is the proper way to adjust ?

Thx
 

cvcman

Registered User
Dec 15, 2011
45
0
0
Do you mean make it a longer time or do you mean make it a shorter time.
Tinker Dwight
Well ive heard that it should run a minute before cycling,,,so Id like to get it to where it should be,,,also would like to understand what adjusting the contact screws does and where they should be
 

Ditto Designs

Registered User
Apr 3, 2004
20
0
1
The Poole clock differs in design than a "regular" pendulum movement, and there are a couple of things to consider when setting up the contacts and optimizing the performance to max out the interval between impulse arm resets.
1. The pendulum drives the gear train through the interaction of the non-escape wheel... the drive mechanism is the interaction of the pawls into the pins on the escape wheel. There is no equivalent to the normal concepts of lock, drop etc - it basically brute forces the escape wheel to move. With that in mind there is really no putting into beat in the normal sense, but you do have to consider the "beat" of the interaction of the impulse arm to the pendulum crutch.... the key to optimizing the transfer of energy to the pendulum is maximizing the drop of the impulse arm and this in part is accomplished by setting the contact screws to the proper position.
2. Simply back out both screws so there is no possibility of electrical contact... manually reset the impulse arm to it's locked position, and start the pendulum swinging. Start with ONE of the contact screws, and give it a 1/2 turn towards the upper contact. If the contact fails to make when the impulse arm is tripped by the toggle, start the process again, by resetting / and giving the contact screw another 1/2 turn until the clock mechanism resets itself properly and repeatedly....then give the screw an additional 1/4 turn for insurance.
3. Take a small piece of cello tape and insulate the contact portion of the screw that you just adjusted. Now do step # 2 above while adjusting the second contact screw.... this way both screws are set at exactly the same trigger point. Remove tape when adjustments are complete.
4. A trick I found to setting the "actual" beat of this clock is to use the leveling screws, and you'll find a sweet spot where the actual drop of the impulse roller to crutch pin is optimized at the best point of the pendulum arc to maximize the energy transfer to the bob. I found that being off-of-vertical. on my particular clock,by about a 1/4 of the bubble in the base level, changed the period of reset activity from 38 swings to 62... you have to sneak up on it, and try both directions off of vertical to see if there is an improvement. So effectively my clock resets itself about every 49 seconds..
Hope this helps.
Mike
 

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