Soundboard 60-ft. Arc

[Greg Newell]

Ron,
    Thank you for taking the time to write all of this. Would you have pictures you
could forward of the rib jig and or your soundboard press? A picture is indeed
worth a thousand words.
    How big is this soundboard press of yours? Do you have trouble storing when
it's not in use? Or is it in constant use in your high volume production
environment? I'm not trying to poke fun. I really have no concept of how busy
others might be. Is this patterned after Clair Davies press? Is this the one
featured in the Journal some time ago? Can you tell me which issue? Was the
pneumatic clamping system expensive?
    Thanks again for your help. It is most appreciated.

Greg

Ron Nossaman wrote:

> >
> > Ron,
> >     Would you care to describe your method of rib crowning a board for me?
> > Also could you suggest some reading I could do on the subject? (I don't have
> > the Journal index on CD) I'm curious to know what I'll be needing. Since I'm
> > heading to a woodworker show this weekend it might be a good idea to have an
> > idea of what faces me in the weeks ahead. THANKS!!!
> >
> >
> > Greg
>
> Greg,
>
> Back when the earth was young, I made a jig. A caul shaped to the chosen radius
> was mounted on it's side on a plywood base. The cut to width rib stock is laid
> in on it's side, sprung back into the curve of the caul and held there by four
> built in clamps while the jig is run through the table saw to produce the
> finished rib height and, when the clamps are loosened and the rib straightens
> back out, the machined crown. Ugly, but quick, simple, and effective. I then
> feather the ribs and clean them up with a little sanding.
>
> For assembly, the pneumatic presses have an appropriate radius cut into the
> caul to accommodate the rib curvature. I will have fitted the panel in the case
> and located and marked the ribs positioning on it. The panel is dried to about
> 6%MC. I start with one of the long ribs, temporarily dry clamping  the one next
> to it to the panel to establish and hold the curve so I have one less thing to
> fight getting that first rib on. I know I could spend 15 minutes and make a
> crude dedicated clamp or two for this, but I never seem to get around to it.
> Then position your pneumatic clamp,  glue on the rib, carefully ease the air
> in, watching to insure that your rib doesn't skate away from it's intended
> position. When you're up to pressure, take off your temporary panel bending
> clamp, move two rib positions over and install the next rib until all of the
> clamps are on. Then go back and move clamps to get the ribs in between those
> already installed. You don't need a lot of press clamps. I use 5. Leap frog
> them as you proceed. There is no sacred order of assembly or other magic spells
> necessary. I don't have the clamps mounted to a frame of any sort, and they
> just go where the panel takes them. It's just simple woodwork.
>
> I use a little straight through T handle valve (1/4" NPT), with a male quick
> disconnect nipple on each clamp. I made a "pig" out of 1 1/2" pipe with five
> 1/4" hoses with female quick disconnects on the ends. There is no plumbing
> between clamps other than the supply line from the pig.
>
> Decide for yourself when is the best time for cleaning off the glue squeeze
> out. It depends a lot on the glue you decide to use.
>
>  That's the gist of it. Details vary with individual preference and/or fetish.
>
> Ron N

--
Greg Newell
mailto:gnewell@ameritech.net