[Harp-L] RE:Was American Chestnut combs, now stainless steel (Vern , Dave , Seth , Gary)

["geoff atkins" <geoffatkins@xxxxxxxxxxxxxx>]

(Re: Comments about weight, construction of SS combs, and dangers to dental
equipment)

Hi Seth, 
strange, the heavier the article the more we seem to equate it with quality,
(unless it's a mountain bike or a squash racket).
The harp is a heavy mother indeed, but feels great IMHO. 
Gary's comment about weight leads me to think I should perhaps have designed
the combs with a knuckle duster and gum guard detail...  :) 
Rubber embouchure?... no.

Hi Vern,
The sound is brighter and surprisingly louder than a wooden combed harp.
Even finger-clamped together, the comb feels more air-tight than timber. 
The whole harp vibrates at certain frequencies, an odd feeling. I'd be
hard-put to make a statement regarding difference to aluminium combs, first
feeling is that it's not as shrill..
A thousand bucks? I do not make wagers, even on certs, (one of my quirks). 
I wouldn't take your money off you, but I'll set up the same equipment and
analysis system (plus a db(A) meter) that I used for the covers experiments,
and we can see the difference. A muso friend has already identified the
quality difference, but he wouldn't take your money either, he's already got
enough.  :)

The laser cut everything in one single movement, to a linear precision of
0.1mm (0.1 mm = 0.00393700787inches) say 4 thou. There is an attractive
visible striation on the cut edges, I'll clock it later.
There was one comb that had spatter on it (the vendor said it shouldn't have
left the shop) the spatter came off in a sheet and hadn't adhered into the
surface.
I'm not going to grind off the striation, no more than I would try to hide
wood grain, (or those lovely blunt saw marks on certain wooden combs :)

The procedure was:
- Measure comb with Vernier (no pun intended) 
- measure reedplate width (I don't want projections)
- Prepare 2D CAD drawing integrating reedplate and comb dimensions
  (For tines I used the overall opening size then subdivided using
   an array command).
- external 4 corners 5mm radius, all tine fronts 1mm radiused
  (square would be a tongue blocker's Freddy Kruger nightmare)
- modify line type to continuous polyline
- Deliver CAD drawing in DXF form for laser cutter CAM drawing
- wait with bated breath.


I had a set-back with the drills today, the local iron store tried to sell
me HSS bits as Cobalt drill quality and prices. Only when I told them that I
already had some cobalts -and knew what they looked like- did they admit
their "error".  ......  :(  welcome to Africa.
I'll shop in the industrial area of the city near the docks on Monday.
The blanks are waiting forlornly in this fuzzy pic. 
(Anyone with a facebook account can see it)

http://www.facebook.com/album.php?aid=102079&id=840522574&saved#/album.php?a
id=102079&id=840522574

It is fun though!
Best Regards  Geoff Atkins