From: WVE~ol.com Date: Sat, 28 Aug 1999 16:50:30 EDT Subject: Re: _Reed_design, long and technical
In a message dated 8/28/99 6:16:06 AM Pacific Daylight Time, gi~aradise.net.nz writes:
> Vern, I am impressed by your efforts. That is amazing.
Please save your amazement for a time when I have equipped a harp with more than just one or two home-made reeds. I mention my reed-making efforts on harp-l only to try to discover others who have worked on the problem and with whom I might compare data and experiences.
> Do you supply F&R >Farrell with their replacement reed kits ?
No. My efforts have thus far been all experimental, not commercial. Even with my newly-automated machine, I do not anticipate being able to offer reeds for sale at reasonable prices.
My process requires shearing a .125 " wide blank from a 1" strip of .013" thick sheet metal, jig-drilling a pair of tooling holes near the ends (one of these becomes the mounting hole) that fit matching pins on the special-purpose mill, and making three cuts on the mill (two straight sides and the curved/tapered top thickness profile). Each cut requires hand-placing and clamping the workpiece on the mill's tooling pins. I use a 1/16" carbide cutter turning about 20,000 rpm under a drip of standard oil-emulsion coolant.
You can see that without automation of workpiece-handling, this isn't a mass-production process. The tolerances are ticklish...getting the sides equidistant and parallel to the mounting-hole centerline and holding the thickness profile close enough to avoid major retuning. My little 2-axis mill has 16,000 steps/inch in the reed-thickness dimension and 8000 steps/inch along the reed-length dimension. One of the big advantages of CNC is that I can compensate for errors of mill geometry in the part programs.
I will share the mill design including electronics and software free with anyone who seriously wishes to experiment with reedmaking. I can save you from a lot of trial and error efforts that cost me several years of fiddling around.
I would particularly like to cooperate with someone who is seriously interested in reed-design, has access to an FEA software package, and is expert in using it.
At SPAH99, Sissy Jones said that Farrell is negotiating with Hohner to offer individual replacement reeds in the future. Hohner will ship them in bulk and Farrell will separate, package and sell them . This will be a vast improvement over cannibalizing reeds of dubious condition from used harps. One complication will be the variety of different lengths of reeds having the same pitch. If I were Farrell, I would require a Xerox copy of the reedplate with every order!
