Repairing Bulle clock Suspensions
By John Hubby
The following is applicable for rebuilding a suspension that still has the *original* Bulle brass end blocks:
1. The original suspensions were made with two pieces of silk ribbon having bound edges to prevent fraying. These can be replaced with new silk ribbon, 1/4 inch wide available at most fine fabric shops. If you can't find silk, polyester/cotton blend will do. Nylon is not recommended because it stretches under load. Do not try to use fabric cut in strips with scissors, it will rapidly fray and have to be replaced. Some of the new synthetic bonded or non-woven fabrics might work but I have not tried any of them.
2. The original brass end blocks (four pieces to clamp the ribbons) had two pieces that were smooth and flat, and two pieces (one for each end) with a shallow rectangular groove cut about 1/16 inch from one of the long edges. When the suspension is assembled, the two pieces with the grooves are set about 1/16 inch apart on a flat surface, with the grooves on both pieces facing up and adjacent to the space between the pieces. I place a 1/16 inch wide brass strip between the two pieces to maintain even spacing during assembly. Two pieces of ribbon are then laid into place at right angles to the grooves, with one piece flush to each edge of the end pieces (I use fabric glue to hold the ribbons in place, available at any craft shop). A strip of lead about 1mm diameter (I use Tix solder) is then placed on top of the ribbon at each groove. The two smooth end pieces are then set in place and clamped to compress the lead strips, then riveted or screwed together. Most of the earlier suspension ends seem to have been screwed together, like 400-Day suspension blocks, and the later ones riveted.
John Hubby dba Pas-Times 400-Day Clock Specialist
P.O. Box 9543, The Woodlands, TX 77387-6543
Member NAWCC, AWI; BHI Associate
Secretary, International 400-Day Clock Chapter #168
Ph: (281) 362-0165 FAX: (281) 362-0514
