Timing Hairspring

[rrmelo]

Hello everyone,

Disclaimer: I AM A NEWBIE. Now that I made that clear, here I go with my tip and trick.

During one of my great horological adventures I messed up a hairspring, well other bits too, but let's focus on the hairspring, so after a bit of work and a now slightly shorter hairspring I wasn't sure if it was going to vibrate correctly. I read a bit about checking vibrations and I came across vibrating tools and methods for counting the balance vibrations whilst watching it, etc. Well, I'm already past my tool budget and really didn't see myself counting vibrations during some sort of time interval, so I thought of something else.

In my set up I have a camera on a goose-neck to take pictures of my work as I go along, this is actually a video camera, so I decided to get the balance cock with the balance and hairspring on one of those pins on a stand, and placed it under the video camera, started recording and then just got the balance going with a peg-wood.

Using a formula, I counted the number of teeth and leaves of the movement train and confirmed the balance should vibrate 18000 times per hour, pretty standard movement.

I got the video on my PC and with a video editor I could watch it frame by frame. In my part of the world we use the PAL system with 25 frames per second. A bit more maths and this balance should vibrate 5 times per second giving 5 frames per vibration.
You will see in the combined pictures below, 1st picture is the starting point, 5 pictures later at number 6 we get 1 vibration and at picture 11 we get the 2nd vibration, so this confirms 1 vibration for every 5 frames. The hairspring is vibrating at 18000 vibrations per hour.

This method is valid for all balances for whatever number of vibrations they should be set to.

Ok, I already had the software and hardware, you do need a video camera, PC and software, but I believe most of us have these anyway. And as far accuracy goes, I trust more the video than my eyes counting vibrations on a vibrating tool.

Now, back to the watch, a few more months and I hope to get it going.

Rod

[tmac1956]

[Arutha]

Brilliant idea Rod!
Now to get on ebay and find a video camera
By the way, is that a balance from a cylinder escapement?

[rrmelo]

Yes, it is indeed a cylinder escapement. It's been a bit of a challenge, the cylinder was bent and I did my best straightening it and getting the walls cylindrical again, it ticks and all, but only face down. For that I am following another thread on the forum where another member was having the exact same problem.

One thing at a time.

It is part of a small beautiful ladies pocket watch which I intend to fix for my wife. Hopefully she will then be in more agreement to my expenditure in horology.

It is great to be pat of the Forum.

Rod

[tmac1956]

rrmelo:

What software and camera combination did you use for this?

Thanks!
tmac

[rrmelo]

Hi tmac1956,

I used an old Sony HDR-SR1 and the Software is the PowerDirector.
The camera, although old, it is HD and has a hard drive too, these days you can get some good deals on used cameras on ebay, they have had such development that the old ones now are just as good.
The software I also got from ebay, it can popup in auction format for reasonable value.

Anyway, I got these to make and play with home videos and now am taking advantage of it in my little horological room, a great help I must say.