Week 31 Feb. 21-26, 2011

Last week I spent most of my time working on hairsprings. I hadn't touched any since before the christmas break so it had been a while. But that was the last part to get the W-01 running so I had to get started.

The first part was to attach the inner part of the spring to a collet. Then you center and flatten the spring to the collet. After that you use the vibration tool to find the vibrating point. It looks like a complicated tool but it's not too crazy. The idea is to pinch the spring at the correct length to make your balance wheel oscillate at the same speed as one of a known frequency. This will ensure your balance will be the right frequency to match the gear ratios of the rest of the watch. In the picture you can see an 18,000 on the side which corresponds to 18,000 vibrations per hour.

Finding the vibrating point is also used to see where you need the spring to come out of the collet (for flat hairsprings). This is because the rate at lower amplitudes changes depending on the angle of the colleting point to the vibrating point. Hopefully this makes sense. If not maybe I should work on that, might have to explain this on a test at some point...

Here you can see the wheels are meant to have the spokes aligned so you can see by eye if the wheels are oscillating together.

As I said before, the W-01 will have a Breguet overcoil. So after I was done finding the vibrating point, I was ready to bend the overcoil. The idea is to make two 35-45° bends to make the last coil higher than the rest. Then you bend the spring into a certain shape according to the diameter you want at the pinning point (end of spring where the clamp pinches it).

I showed a picture of the different overcoil shapes last week, here it is again. I originally picked the one in red, but I had to use the one in green after finding the vibrating point to be much longer than before because of the heavy balance wheel. As you can see, the lower the number, the closer to center C becomes. I had already made the clamp so I had to follow the pattern that matched the diameter of the clamp.

The overcoil was not really that difficult to bend for me. I built a little tool to help me bend the overcoil part of the spring that worked really good. It was just a really thin plate of brass that I could slide the majority of the coil under, and then just work on the overcoil part. It helped keep it much more flat and straight. But it still did take about 3-4 hours to get it looking nice and following the correct shape. You can see in the photos the last part of the spring seems to rise up a bit so I'll have to see what is causing that.

Here you can see the two bends in the spring that raise the last coil up. Then from there it goes overtop and around to where the clamp is. 

And here you can see where the clamp pinches the spring. That is the exact point I want the vibrating point to be. It will take some time and skill to get it perfect, because this is what sets the rate of the watch. even a few hundredths of a millimeter to the left or right could make the watch go 10-20 seconds faster or slower. 

There is also some extra spring sticking out on the right side that I will trim off later when I know the exact location. 

So after putting the spring in the clamp the watch was ready for its first oscillation! I just wanted to see it working so I didn't clean and oil everything, but it still worked fine on the first try. It was very satisfying to see it finally come to life. It was also cool to see the overcoil as I hadn't really looked at one up close (even though we have worked on Rolex watches with overcoils, I just never really looked at it). 

Next thing I did was clean everything to see if I had a decent amplitude. We had to make the balance staff so you never know if things are going to work great on the first try. I had 290° amplitude in the horizontal position so that was a great start. The vertical position wasn't that great (215°) but there are a lot of reasons as to why. I now have to start fine tuning to get the results I am looking for. But here's a quick video of the watch actually running!

One other thing to mention about the overcoil. f you watch the video you can see how the spring expands and contracts evenly around the entire spring. This is because the overcoil places the center of gravity in the center of the balance. On a flat spring the center of gravity is not in the center of the balance so the spring will expand and contract a different amount in different spots. This is one of the benefits of the overcoil.

I am also working on getting the AMS1 running. It will have a flat hairspring so I will have more examples of that later. But I put in the eccentric banking pins and I think they look cool. Now I still have to adjust them and also make a spring for that balance. And I have to figure out a way to make some regulating pins. They are extremely small so it's not going to be fun...

Week 30 Feb. 14-19, 2011

Holy cow, 30 weeks doing this already. Seems like I could've accomplished a lot more. I suppose I didn't originally have a CAD program or plan to make my own mainplate so maybe it's more like 20-25 weeks realistically. But anyways here's the scoop on last week.

I actually didn't do a hell of a lot. I started the week in hopes of making the balance staffs needed for the W-01 and the AMS1. I finished one for each. I will still need to make another one for the AMS1 but for now it is fine. I will use the first one to rivet to a test balance wheel so I can do all the testing without using the nicely decorated balance wheel I plan to use.

Just to test the staff I made, I glued it to a temporary balance wheel. The staff was just the right length at the extra 0.18mm I had calculated. In these first two pics I was just testing the staff to see if the pivots fit and if it was the right length.

Not the nice balance wheel like the one with the screws...

Next I riveted the balance staff for the W-01 onto the nice balance wheel. The screws are for regulating the watch. This is also the underside of the wheel.

Next I started making the spring clamp. Usually there is a stud that holds the one end of the hairspring with either a pin or shellac. But this design is a little more solid and suits a Breguet overcoil design a little better. Note: a Breguet overcoil is just a different shape of the end of a hairspring to aid the center of gravity of the spring. Normally a hairspring only expands and contracts one way because of its shape. But the overcoil reduces this effect creating a better timing between the 6 different positions (crown up, left, right, down, dial up & down).

Here you can see different shapes of overcoils, depending on the radius of the end point. I chose the one circled in red. We have to bend the spring by hand in the air. I'm sure it won't be easy...

So anyways, the design is pretty simple for the clamp. Just a disc that has a flat face on one side, with a steel piece screwed on creating a clamp. This is the underside....

The spring will go into the spot indicated by the green arrow. Please forgive my horrific attempt to free hand draw a hairspring in photoshop hahahaha. More info on balance springs here.

I had to drill and mill holes in the bridge to fit the screws. These are some of the smallest screws I've had to make. The head is 0.60mm, thread 0.50mm and the length is only 0.80mm. The one for the clamp is really small as well. I think I will be making all the screws blue.

The end of the screws will be polished so you will just see two circles. The top of the clamp will also be flat polished.

Here you can see what it will sorta look like with the pallet fork bridge and balance wheel. Very simple design but nice I think.

I think I will try to leave the arms of the balance in this position. That way it won't block anything from view when the watch isn't running (not like that'll really matter, but still).

As for next week I will be finishing the bridges and hopefully bending the spring to get the watch working! See ya

Week 29 Feb. 7-12, 2011

*Update: added a few photos of the barrel bridge stem cut out

This week was quite a bit worse than last week as far as getting things done. On Monday I tried to cut out the recesses for the balance bridge but it didn't go so well I ended up making another one and finally got it to work. 

I was testing the bridge with an original balance wheel and staff and as you can see the mainplate jewel is sticking out quite a bit. This just means the balance staff I make will have to be a bit longer, not a big deal.

Then I worked on the recess for the sliding and winding pinion on the barrel bridge. I didn't really have the right tool or machine to make the correct cut out on the bridge so I had to improvise. It is supposed to be a curved shaped cut out for a round piece but I just made small steps in the material to create the recess. I forgot to take a picture of it so I'll have to update this tomorrow otherwise this makes hardly any sense. But anyways, you can't see the recess so it's not a big deal what it looks like really... Here's a pic of cutting the recess for part of the winding stem out of the bridge and mainplate.

Pic of the original (left) and the AMS1 (right)

Then I had to make a winding stem since the hole in the mainplate and bridge are a bit bigger than the original one. Only took about 3 hours (compared to the 6 or so for our exam) since I didn't really need it to be nearly half as accurate. Here are a couple pictures, with a temporary crown glued on.

Next thing I had to make was a new setting lever spring. The one I had made before was nice but it wasn't quite working properly on account of the shape of the spring. It was curved the opposite way and was too strong. Also when you pulled the stem out, the pin would jump out of the notch because there wasn't a big enough rest for it. So here is the picture of the new one on the left. It all works great now and the functions are smooth.

Saturday I decided to make a few of the parts needed for the moon phase. The springs were simple to make, but I found hardening and tempering them a bit tricky. They are very thin (0.20mm) so I was worried they might become bent while hardening. I first tried to put them in this tube (pictured) with some charcoal inside but the springs didn't get hard. Then I tried pressing them between two thin plates but that didn't work either. Finally I ended up making a little basket dealy out of wire that I wrapped around a piece of steel first. Then I put one spring in at a time and that worked great. They came out still straight and finally hard. 

As for an explanation of the springs. There needs to be a spring holding the star wheel and the moon phase wheel in place when they are not being activated. It keeps the wheels from moving and also so that the finger of the cam will always activate in the same place. The photos explain best I guess so just take a look. I know, I know the teeth on the moon phase wheel are backwards. That's just the spare trial wheel and I did a trial decoration on the underside of the wheel. It is just in upside down to see the decoration....

So next week I have to get started making balance staffs. I need to make 1 for our school watch W-01. And I should make maybe 2-3 for the AMS-1 since I would like to have one for a trial balance, one for a good nicely decorated balance, and one for a spare in case I ever break one. I could make a spare for the W-01, but I figure it would be not so likely I would break a balance staff in a pocket watch that isn't used. But anyways, not looking forward to a whole week or so making balance staffs. Nicholas if you read this maybe you can make me one?? Haha, cya next week...