?HAC Pendulum adjustment?

[ARw]

I have a HAC round face wall clock, non striking, reverse painted glass dial.

I'm not sure that it has all original parts, but I don't see a means of adjusting the pendulum length. There are slotted holes which would allow the pallet engagement depth with the escape wheel to be adjusted, but I don't think that would change the time keeping.

Does anyone have information or thoughts on this?

 

[JTD]

Unless we can see a photo of what you are looking at, it is very difficult indeed to give any helpful advice. Please post photos and there will be help forthcoming I am sure.

JTD

 

[Uhralt]

I would say it is likely the wrong pendulum bob. Get an adjustable one.

Uhralt

 

[ARw]

I would say it is likely the wrong pendulum bob. Get an adjustable one.

Uhralt

I think you're right. I've had this clock for 40 years and am just now thinking about getting it running.

Has anyone seen one of these with its original pendulum?

 

[JTD]

Unless we can see a photo of what you are looking at, it is very difficult indeed to give any helpful advice. Please post photos and there will be help forthcoming I am sure.

JTD

Thanks for the photos - these were not visible when I wrote.

JTD

 

[ARw]

Yes, thanks JTD. I finally figured out that I had to compress photo files before they would load.

 

[Willie X]

If the one you have is in the ballpark, Merritt's #P98D, or #P98C, should allow you to zero in on a good rate.

The smaller D @ 1 1/2", will give you a slower rate than the C @ 1 3/4", all else being equal.

Willie X

 

[ARw]

Thanks, Willie.

I'll check those out, but first I have to get it running so I can observe the rate.

 

[Willie X]

Yes, first things first. Willie X

 

[ARw]

I got the HAC cleaned and put back together today. Good news is that I think I found the correct pendulum bob in an old box that had contained the HAC and a Seth Thomas mantel clock with a built-in pendulum adjuster.

I put the solid bob on the Seth Thomas, and the adjustable bob on the Hack. Both are running at about 82 to 83 swings per minute, when measured on my optical tachometer. I have no idea what a typical number would be. I guess I'll find out tomorrow when I see if they are keeping time.

 

[Uhralt]

I got the HAC cleaned and put back together today. Good news is that I think I found the correct pendulum bob in an old box that had contained the HAC and a Seth Thomas mantel clock with a built-in pendulum adjuster.

I put the solid bob on the Seth Thomas, and the adjustable bob on the Hack. Both are running at about 82 to 83 swings per minute, when measured on my optical tachometer. I have no idea what a typical number would be. I guess I'll find out tomorrow when I see if they are keeping time.

It seems you found the solution.

Uhralt

 

[ARw]

Good news: The HAC is hanging on the wall and has been running for 3 days and has only lost 1 minute. I should b e able to regulate that.

The amplitude of swing seams short to me at about 1/2 to 5/8 inch at the bottom end of the adjusting screw. It makes the clock very sensitive to hanging angle error. Maybe that is the reason for the fork at the bottom of the clock to lock it in place once the (would beat be the correct word?) tick-tock are set equal?

 

[JTD]

Maybe that is the reason for the fork at the bottom of the clock to lock it in place once the (would beat be the correct word?) tick-tock are set equal?

Yes, that is to stabilise the clock - once you have it in beat on the wall. You put a scrrew in the slot to hold the clock in place.

JTD