Semester 2, Week 3, Days 4 & 5 (More ETA movements)

Thursday, I was able to get the watch back together without any other issues and the oiling went really well. I only had to remove the pallet fork one time to clean it an extra time. If you go back to this post, you will get a refresher of how I am going about oiling the pallet stones. Now, there is a treatment that I will eventually do with the pallet stones called Epilame that is supposed to make the process of oiling the stones a lot easier, but I don’t think I’ll be doing that until my fourth semester. In simplest terms, Epilame is liquid that helps keep lubricants where you put them in areas where they tend to spread/travel away. There are issues with Epilame if it isn’t done correctly, which is why I am not using it right now.

Once I got the watch put back together and fully oiled, I had to time it out. When I first put it on the Witschi, it was running about 2 minutes fast with a beat error of .4 ms. The amplitude was around 290°. Needless to say, I was not too happy about that. I moved over to the timegrapher and ran a quick tape on it. About 10 seconds into the tape, I noticed that both the timegrapher and witschi were set to a bph of 28800 with a lift angle of 52°. The 6497 has a lift angle of 44° and bph of 18000. I slid back over to the witschi and made the adjustments to lift and bph and the amplitude got down to about 230°. It was still running fast and had a beat error, but making sure I had the right settings on the machines was the first thing to do.

Addressing the fact that it was running fast was pretty simple since the regulator arm is easy enough to move. I was getting ready to pull the balance so I could adjust the collet to get the watch in static beat when my instructor let me know that the 6497 has a beat adjuster arm that I could turn that would adjust beat error. I was pretty excited because non of the watches I worked on last semester (regarding timing) had a beat adjuster. Putting a watch into static beat by adjust the collet isn’t hard, just time consuming. Having something that I could adjust on the watch while the watch was on the timing machine and see the immediate results made the process go a lot faster. Moving the beat adjusting arm caused the rate adjusting arm to move as well but it managed to move it the direction I needed (lower the rate). Once I got the the beat to 0-1 ms, I made my final minute adjustments to the rate and was very pleased with how it turned out. It was holding steady at 0-1 ms and was running at 0-+3 seconds in all positions. The whole timing process took about 5 minutes as opposed to 15-20 minutes last semester.

Once I turned in the 6497, I was given an ETA 7001 to work on. I knew that it was going to be smaller, but the difference in size is pretty stark. The ETA 6497 is 16.5 ligne movement (36.60 mm/1.44 inches wide), and the 7001 is a 10.5 ligne movement (~23.7 mm/.93 inches wide). I was able to get the pallet stones done pretty quickly (and put in the right way the first time!) and disassembled and ready for cleaning on Monday.




Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s