Hello, Un warping keys in soft wood is done efficiently with 2 irons and a wet rag, then an twisting with a weight or pliers. Once done it stay where it is enough IMO. I also do it with a hot gun with good results Keys in harder woods are more difficult to unwarp definitively. Understanding where the warping comes from is the most difficult part, as not overdoing it, but I prefer to unwarp the best I can, and finish playing with the pins alignment to get the keys level and squared as much as possible. I agree 100% with the new heel cloth (well tense and good action cloth of course). The use of hide glue is a must to get the wanted tension in that place, and yes it pay well for the touch feeling (minimal friction and noise). Isaac OLEG -----Message d'origine----- De : caut-bounces@ptg.org [mailto:caut-bounces@ptg.org]De la part de Mark Cramer Envoyé : vendredi 6 août 2004 18:44 À : College and University Technicians Objet : RE: capstan spacing Hi Allen, FWIW, here are some thoughts on key/capstan spacing and alignments. I prefer to work spacing/alignments from "both ends twoards the middle," i.e.: I want to have the keys evenly spaced and square, including the sharps well centered, and I want to have my hammers traveled, twisted and spaced for uniform shift, with flanges as parralel and evenly spaced as possible. I do not want to compromise key-space or hammer-space (if at all possible) for internal alignments. Now (in my humble understanding) I have the knuckles and capstans where they belong, (process vertical actions/keyboards exactly the same way)... and the fight begins!! ;>) With twisted keys, I am willing to (and routinely do) sand key-sticks for clearance from each other, and clearance from adjacent under-levers in shift position. (I must buy into the assumption that a twisted key is going to stay twisted) On occassion, I've sanded a fair amount of wood from the back end of a twisted key to have working clearance and preserve optimum squareness/spacing at the "user-end" of things. Recently, I removed a capstan which was square to the top surface of it's twisted key-stick and re-installed it "crooked" in order to have it square in relationship with the wippen. (I remember straightening twisted keys once (held in a vise) by steaming over a kettle, using the weight of a metal C-clamp (leverage/gravity) to influence the key back to square, however, can't remember the piano to tell you whether it lasted) Regarding wippens, of the three alignment methods discussed, I use lateral spacing and lateral flange-traveling to correct space, preferring as you mention not to rotate the wippen out of square with the knuckle. (will rest a straight-edge over a section of freshly spaced wippens to verify this) Space to the knuckles first (from the back of the action), ignoring heel/regulating button contact initially, as the latter offer a fairly generous contact target compared to the former. >From the front of the action, I'm likely looking for a safe capstan clearance from neighboring heels over full range of motion, even more than idealized contact with it's own wippen heel. Sorry Allen, I've forgotten whether the work you described includes new wippens, or just new heel cloth. The latter job (IMHO) ranks right up there with damper guide-rail re-bushing on the "work-related satisfaction meter," especially if you include a nice red bushing cloth bolster. (I've "bolstered" existing heel cloth to restore shape and tension, and experimented with steam, but have limited success restoring the dimpled contact area) In any case, new cloth provides a nice, wide, dimple-free target, even if the capstan contact needs to be quite near the edge. Certain actions offer more of a fight than others, and in some cases I will oval the flange-screw hole to gain more lateral space along the rail. So "yes," I guess I would be willing to move capstans to idealize contact, and in your situation, "now is the best time." As a personal operating value however, I guess I would choose "squareness" of motion and contact over target-centering. However, sometimes we don't have that choice. Happy aligning! Mark Cramer, Brandon University -----Original Message----- From: caut-bounces@ptg.org [mailto:caut-bounces@ptg.org]On Behalf Of Allen Wright Sent: Friday, August 06, 2004 9:21 AM To: College and University Technicians Subject: Re: capstan spacing Fred, Very interesting procedure you describe. Thanks! Allen On Thursday, August 5, 2004, at 11:06 PM, Fred Sturm wrote: > --On Thursday, August 5, 2004 9:39 PM -0400 Wimblees@aol.com wrote: > >> In a message dated 8/5/2004 8:07:55 PM Central Standard Time, >> awright440@cinci.rr.com writes: >> >> If keys are warped, is it possible to straighten them out, and if so >> how? >> >> >> I've been told to heat the key, and while the wood is warm, twist it >> in >> the direction it needs to go, then take away the heat. (Just like >> bending >> shanks.) I have tried to do this several times, but have never been >> able >> to successfully do it. >> Maybe someone else has a better idea. >> >> Wim > > Actually I do have what I think is a better process. Easier to show > than describe, but I'll try. I use a jig consisting of a length of 2 x > 4 with a small wooden block in the center. I clamp the key to the > block (and 2 x 4) using wooden handscrew clamp (could be done with a c > clamp and block just as well). The idea is to immobilize the key at > the balance hole, but support it out a ways on both sides to avoid > undue stress on that weak point. The balance hole portion of the key > should be centered on the block, and the hand screw or c clamp block > should straddle the balance hole. > I then place a wedge of the proper height and angle between key and 2 > x 4 toward the end of the key, engineered to make the key twist in the > direction I want it to go. Or, if all that is desired is a straight > bend, I place a square block similarly. The block or wedge should be > sized and/or shaped to allow the key to move in the desired direction > about twice the distance you want it to end up. > Then I clamp the end of the key to the block or wedge, and apply > steam with a steamer (travel steam iron by preference, or a teakettle > spout. I find the pressurized steamer puts out too much pressure and > not enough wet and heat). Give it a good long shot of heat and wet. > Follow with a heat gun (mostly to dry it and speed up the setting of > the wood). Allow to cool and remove the clamp. Measure to see whether > you got the results you wanted (I forgot to mention measuring before > clamping, so you know where you were when you began). > If necessary, reclamp, maybe with a shorter block or greater-angled > wedge and resteam. Or, if you went too far, it's usually very quick to > get back to where you were. I'll say that this procedure is usually > reliable, though sometimes I have needed to redo it. So I have learned > to aim at a little beyond where I really want to end up, figuring the > wood will tend to move maybe 1/3 the way back toward where it was. > I should also note that I have had some rather disastrous results > with the method Wim described, trying to twist too hard (breaking the > key) and various bad experiences with cutting kerfs and inserting > wedges. Sometimes I succeeded, but more often had a mess to try to > rectify. > I haven't used the method I described above enough to feel really > confident about its permanence, but results so far are encouraging. It > is, at any rate, the most controlled and controllable method I have > ever come up with or heard of. > Regards, > Fred Sturm > University of New Mexico > > > > _______________________________________________ > caut list info: https://www.moypiano.com/resources/#archives > _______________________________________________ caut list info: https://www.moypiano.com/resources/#archives _______________________________________________ caut list info: https://www.moypiano.com/resources/#archives
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