It is amazing at just how many times we have seen this happen. It seems like people who do not know how to recognize the difference between a riveted staff and a friction fit staff are winning the battle and at the same time destroying many valuable balance wheels.
We have actually seen watches come into our shop where someone has made an attempt to replace a friction staff, not knowing that it is a friction staff. They place these into a lathe or worse, into the staking set, and attempt to either cut or drive out a friction staff. The result: A very badly damaged balance wheel arm.
The other problem we have seen is that the wrong size stump or on the Inverto sets, the wrong stake was used. The selected stake did not support the hub on the balance arm. When the attempt was made to drive out the staff, the whole staff and the hub was driven out of the balance.
What to look for:
Most of the time, a friction fit hub will always be a blue steel color. This alerts the watch repairman that there is a difference between the staff and the hub.
Howard watches most of the time on their friction fit staffs would mark the underside of the balance bridge with a notation that said, "Friction Staff."
Once a determination has been made, you must select the correct stump or stake that will firmly support the hub on the balance while at the same time allows for the removal of the staff. You can drive them out with very light taps from a watchmakers hammer or you can use the jeweling press attachment on the staking set to simply press the old balance staff out. Doing this will insure that the hub will remain firmly attached to the arm of the balance wheel.
Now the balance can be flipped over and supported on a proper size stump or stake. Use the correct size that will allow for a little more clearance, just enough for the new staff to be driven into the hub, while still supporting the hub and allowing the staff to clear the hole in the stump or stake.
It is also a very good idea to use a lubricant on the inside of the hub, some fine watch oil will work, before driving in the new balance staff. This lets the new staff glide into the hub reducing metal-to-metal contact. Remember, when the job is done, you must clean the watch and balance assembly, so a little oil here is not a problem and really helps the new staff go into position.
It is also important to remember to always align the stumps or the stakes so that they dead center to each other. If you don't, and they are off center in the least amount, you will either ruin the new staff, break the hub, or bend the arms of the balance wheel.
Take your time to examine each balance. Study it carefully and determine your plan of action. A little time here will save you literally hours of time trying to correct damage to an otherwise perfect balance wheel.
We have actually seen watches come into our shop where someone has made an attempt to replace a friction staff, not knowing that it is a friction staff. They place these into a lathe or worse, into the staking set, and attempt to either cut or drive out a friction staff. The result: A very badly damaged balance wheel arm.
The other problem we have seen is that the wrong size stump or on the Inverto sets, the wrong stake was used. The selected stake did not support the hub on the balance arm. When the attempt was made to drive out the staff, the whole staff and the hub was driven out of the balance.
What to look for:
Most of the time, a friction fit hub will always be a blue steel color. This alerts the watch repairman that there is a difference between the staff and the hub.
Howard watches most of the time on their friction fit staffs would mark the underside of the balance bridge with a notation that said, "Friction Staff."
Once a determination has been made, you must select the correct stump or stake that will firmly support the hub on the balance while at the same time allows for the removal of the staff. You can drive them out with very light taps from a watchmakers hammer or you can use the jeweling press attachment on the staking set to simply press the old balance staff out. Doing this will insure that the hub will remain firmly attached to the arm of the balance wheel.
Now the balance can be flipped over and supported on a proper size stump or stake. Use the correct size that will allow for a little more clearance, just enough for the new staff to be driven into the hub, while still supporting the hub and allowing the staff to clear the hole in the stump or stake.
It is also a very good idea to use a lubricant on the inside of the hub, some fine watch oil will work, before driving in the new balance staff. This lets the new staff glide into the hub reducing metal-to-metal contact. Remember, when the job is done, you must clean the watch and balance assembly, so a little oil here is not a problem and really helps the new staff go into position.
It is also important to remember to always align the stumps or the stakes so that they dead center to each other. If you don't, and they are off center in the least amount, you will either ruin the new staff, break the hub, or bend the arms of the balance wheel.
Take your time to examine each balance. Study it carefully and determine your plan of action. A little time here will save you literally hours of time trying to correct damage to an otherwise perfect balance wheel.
