This vintage Rolex 1030 movement arrived in sad shape. It had a number of problems, one resulting from lack of regular servicing and the other from botched work. Our first task is to repair a worn arbor bushing in the barrel bridge.
This is a good example of what happens if you don't service movements on a regular interval, and remove the gunk that was oil and that at one time lubricated the pivots. But now, as a result of contaminants such as dust (which is very abrasive), the oil has become an effective grinding paste which very quickly can wear the pivots and arbors, with no access to spares, especially where vintage watches are concerned, the only hope is to restore the watch by repairing it, as such you can expect higher repair costs than servicing alone, along with loss of originality.
So lets have a look at the state of the movement, always a surprise to see the dirt and gunk that seeps past the worn out dried o'rings in the crown and tube. One of the biggest weaknesses of poor servicing, no one seems to want to change the o'rings in the crowns and tubes.
This looks like a piece of aluminium and how it got here is beyond me.
During the disassembly I notice a wear mark on the barrel bridge, there shouldn't be one because the winding wheel should not touch the bridge
and on the winding wheel there is also a wear spot
So next I check the end and side shakes of the barrel and this is what I find.
With the barrel sitting normal there is the proper clearance between it and the bottom of the barrel bridge.
If I press on the side of the barrel with a piece of pegwood this is what happens, there is so much side shake that the barrel is touching the bottom of the bridge, this is not acceptable and has to be repaired.
If you look closely at the barrel bushing you can see that one side is worn out.
So I can't leave that damage in place, it has to be repaired.
Barrel Bridge repair
The bridge is removed and installed in my jewelling tool for reaming of the hole. I use the jewelling tool not only because it has reamers, but more importantly the hole I cut has to be perfectly upright with regards to the bridge, using the jewelling tool ensures that it's done properly.
Overall view of the tool with the reamer in place and ready to cut away the damage. Because the damage is less than 1/2 of the overall circumference I am not worried about the new hole not being centered, or that I create a depthing error between the barrel and center wheel. I remove a bit of material at a time, and check as I progress on the relationship between the wear mark and the new hole, once the reamer reaches the same circumference as the wear spot, I'll stop.
Close up view of the reaming taking place.
Here's the results, a nice round hole perfectly centered on the original location.
With that taken care of, I am left with a burr on both sides of the bridge, so these are carefully removed with a cutter, done by hand so that I don't take away too much material.
Next step is to make a new brass bushing, starting with some raw round bar in the lathe. The ID is drilled undersize so that I can custom fit it to the arbour once it's in place.
The OD is machined to a few hundred's oversize so that I can get a nice friction fit.
Here's a view of the gap I have to fill, you can see the barrel arbor location compared to the enlarged hole that the bushing has to fill.
The new bushing is parted off and ready for installation, it is seated from below, just flush with the top surface.
Close up view once it's pressed home and secured with a drop of loctite.
Extra material left over on the bottom of the bridge that I will file away very carefully.
And with some careful reaming the final fit with the end and side shakes adjusted, problem solved...but more to come, there were other issues that needed fixing. Stay tuned for Part 2 of this job.
So after the repair to the barrel bridge, the remainder of the servicing and inspection and assembly went well. No other problems were noted with the movement, that is until I wound it up and was faced with a balance doing about + - 90 degrees of amplitude.
After all the normal checks under my 4X loupe and not finding any issues, I got out the microscope and had a closer look at the staff pivots, and noted that they had circular groves on them as well as a slight bend.
Balance Staff Replacement
I went ahead and removed the collet and hairspring, normally an easy job, but instead of the normal twist the collet off while pulling up and it loosens and comes right off, in this case the collet was doing the reverse, and tightening as I tried to remove it. Only by using the lifting levers was I able to get the collet off and then I immediately noted the problem, the collet seat on the staff was quite damaged and covered with turning groves. Taking off the roller table I found similar damage, so someone replaced the staff at some time in the past and did a botched job of it.
Here's a view of the staff, if you wonder why I didn't note the pivot damage under the 4X loupe, consider that the overall length of the staff is 3mm and the pivots have a diameter of 0.07mm, quite small by anyone's standards.
Note how rough the collet seat is.
Here's an overall view of the balance with old staff, the roller table and the hairspring
I know that some watchmakers believe that cutting away the staff rivet is not required before you punch out the staff, but I am not one of them.
The only proper way to ensure that you don't damage the balance arm during staff removal, is to cut the rivet on the staff that secures it to the balance arm. The balance staff is attached to the balance arm by peening and riveting the staff to the arm, so before pressing the staff out of the arm I will cut the rivet head off, here is the balance in the lathe getting the rivet cut off.
Once the rivet head is gone, there is no risk of damage to the balance arm, so the staff is pressed out with my Platax tool.
Staff is out and no damage caused to the arm.
Next up, lets install my new staff.
New Balance Staff
Here is an overall size view of the new staff before installation.
And here is the staff being riveted in the staking set. I always use a stump or a reverso punch to not risk damaging the plate on the tool.
Next the roller table is installed, then the balance is mounted in the movement and the balance cock put in place and secured. Before going any further I check the end and side shakes and the alignment with the roller table and pallet, it all looks good. Here is a nice close up of the pallet and roller alignment.
The next mandatory step is to "poise" the balance, making sure it has no heavy spots. Of all the steps required for a proper staff replacement, poising has to be the most important as far as time keeping is concerned.
The balance with roller table installed is mounted in a perfectly level poising tool, and rotated gently. Never blow on any watch parts, especially a balance, blowing always includes spit, which is not good for watches at all. The fine paint brush is used to gently rotate the balance checking for a heavy point.
For the poising to be accurate, the staff has to sit on the flat part of the pivots, not on the rounded conical section.
It's unlikely that you will ever have a staff replacement where the poise is good, in this case it was out, one side was very heavy, most probably partially due to the botched work of the prior watchmaker.
In fact the poise was out by so much that I had to install copper washers on the light side of the balance to get it even close to being poised.
Here you can see the copper washers being installed under the timing screws.
Once I had the washers installed and the poise close to what it needed to be, I did the final adjustment with the cutter and removed a slight bit off the heavy screw head.
Next step is to reinstall the hairspring, making sure to get the beat as close as possible to avoid repeated removals and installations of the balance wheel.
And finally the balance is installed on the movement, it's given a wind and the amplitude is now over 270 degrees up from the 90 degrees I had with the old staff. I check the poise by placing the movement in a vertical position on the timer, and because there is no change to the rate it confirms that the poise is good.
If this movement had been serviced at regular 5 year intervals, it would not have worn out the barrel bushing. As far as the original damaged balance staff, that comes down to an unqualified or unskilled watchmaker not doing his job properly. Moral of the story, service your watch on a regular basis and make sure you use a competent watchmaker. Thank you for reading.