One simple tool to use when adjusting damper timing is a modified clothespin. Using a dremmel, you can make the clothespin very thin so it fits between dampers and holds your target position while you make adjustments from the keybed.
Clothespins are gentle enough that they won't damage the damper, but are strong enough to hold it elevated in the desired location. They also allow enough precision to make very small changes to damper timing.
Using your handy Bessey 3-inch Clamp-on Vise, insert the clothespin close to the spring and tighten the clamp to open the clothespin widely. Shave down one side of the clothespin so that it is nearly flush with the center hole in the clothespin. Flip the clothespin around and do the other side. Make at least six so that you can use two in each section of the piano to set damper timing.
By Hannah Beckett, RPT