Using Rulon Tape as a Bearing Edge on Timpani
The author has used 1 inch Rulon tape (a PTFE derivative) as a bearing-edge surface on drums with wide, rounded bearing edges with great success. Rulon tape is thicker than the traditional PTFE (“Teflon”) tape used by some professional timpanists (often ~3 mil). The RU-series film is typically ~8 mil backing thickness (plus adhesive).
The “wide-lipped” drums are excellent for producing a period sound with slightly less resonance and sustain than “thin-lipped” instruments, yet they yield a prominent principal tone. (see The Bearing Edge) Rulon is a PTFE-based material that works very well as a low-friction bearing-edge interface. The following video demonstrates how to prepare a timpano bowl to receive Rulon tape on the bearing edge and how to apply aerosol PTFE spray.
N.B. Adding any material to the bearing edge introduces a thin interface layer that can slightly alter boundary friction/damping and can also change thermal coupling at the contact region. Some players report that PTFE tape of any kind “deadens” the sound of the instrument. While any added layer at the bearing edge can, in principle, modify the boundary condition to a small degree, the author has experienced no noticeable degradation in pitch clarity or overall sound on the instruments tested.
Rulon tape: CS Hyde Co, IL, USA
Rulon® is manufactured from skived compounded PTFE Rulon® film material. The RU-Series is often referred to as bearing tape and offers outstanding abrasion and temperature resistance as well as enhanced wear resistance in a PTFE fluoropolymer based material. Both Rulon® tapes have an 8.0 mil backing thickness and 2.0 mil of pressure sensitive adhesive for the silicone system and 2.3 mil of pressure sensitive adhesive for the acrylic system. Color is Raspberry Red. Available in slit rolls in 5 yards or 18 yards.
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