Ed: >"Friction free" bearings- well, harpsichords approach this, and they >tune easily with a T hammer. An impact hammer might work well on a >vertical piano with low friction. But this assumes you will use >standard tuning pins. I wasn't assuming any particular type of tuning pins. Just imaginary ones for now. >What do you mean by "solid, stable front and back lengths?" Meaning some means which is rigid enough that it is stable. Any instability in the non-speaking lengths will be instantly transmitted to the speaking lengths if there is no bearing friction, thereby making them unstable too. >Same total string lengths within a trichord should help with >stability over temperature and humidity change. Yes. >If this is a purely hypothetical piano, why not get rid of the front >lengths entirely? Have the string connect directly to the front >termination point. You need separate points for acoustic and mechanical termination, unless your acoustic termination is grounded (to hold the tension force). So, in principle, you could have both the same, but only at one end of the speaking length (e.g. strings tied at a movable agraffe). The other end will need a separate mechanical and acoustic termination so you can hear it, and therefore at least a backlength is unavoidable. Stephen -- Dr Stephen Birkett Associate Professor Department of Systems Design Engineering University of Waterloo Waterloo, Ontario Canada N2L 3G1 E3 Room 3158 tel: 519-888-4567 Ext. 3792 fax: 519-746-4791 Piano Design Lab E3-3160 Ext. 7115 mailto: sbirkett[at]real.uwaterloo.ca http://real.uwaterloo.ca/~sbirkett
This PTG archive page provided courtesy of Moy Piano Service, LLC