Hi Les, Today was a quiet day in the workshop so I took what we had discussed and played around a little. This is the conclusions I came across. I took six new hammers out of a part set, numbering 28, 29, 30, 31, 32, 33. I tried to weigh these unfortunately my weighing scales said they all weighed 10 g. I payed a visit down to the local shop and found his weighing scales no better than mine. All is not lost, the idea of the experiment was. To take a controlled amount from the sides of the hammers to alter the weight. So I measured them with a micrometer and they where 9.60 9.56 9.57 9.55 9.77 9.87 quite an variation all were measured at the same place if this was mirrored thurout the set it gave you plenty of scope 9.50 I think is the lest you could go down to. I decided to go for the 9.56 and reduce all to that level just to see if I could control the amount I could take off accurately. The problems: How to clamp the hammers without damaging them. I overcome this by using a small wooden platform measuring 200 mm by 80 mm on the 80 mm side, I placed a 9 mm high strip as a stop. I then took another piece of wood 10 mm by 9 mm by 200 mm. I then placed this at an angle, representing a gap of 10 mm at one end 50 mm at the other end. This gives you a V shaped slot. Placing the hammer with the tail at the thinnest end and pushing down until it was reasonably held. This I felt was secure enough, as I was going to use my pillar drill with a grinding disk. The downward pressure and sideways pressure would ensure the hammer head would not move. I calculated that two blocks of similar design but the angle set at a greater depth on the second one this should enable all hammers to be held in place ( this method allows you to turn the hammer over so you can reduce on both sides). I used a disk in the end with 340 grit wet and dry stuck to the disk. With the pillar drill coming down and circular movement of the disk it keeps the hammers in place. I could take off small amounts quite easily even with my naff pillar Drill. (I felt that I need a better Drill if I'm going to do this on a regular basis with contorol of 0.1) To sum up, if a technician was to take this on a regular bassis the purchase of quality weighing scales would be essential, a high quality pillar drill with good control. Accurate measuring of particular makes of hammers throughout the range should give you, amount to weight ratios this is so that you can speed the job up. For the sake of arguments, number 22 hammer of a set of ables 14lbs hammers. take off .2 mm would represent .2g. This of course is a theoretical scenario. But with practice and accurate record keeping I would imagine that sort of data would speed up what looks like a rather time consuming job. However, I now, can well appreciate the benefits of weighing individual hammers and hammer shanks. To obtain better quality control. You've sold me on the practice of weighing individual hammers. thanks Les and Jon. Barrie, In article <Pine.BSI.3.95.970322144421.8188A- 100000@buffnet7.buffnet.net>, Les Smith <lessmith@buffnet.net> writes >Hi, Barrie. > >We're in absolute agreement over the hammer shanks impact on tone >quality. Essnentially the important factor seems to be the flexi- >bility of the different woods. For example many older US-made pianos >used cedar for their shanks a relatively more flexible wood than >the maple used today. We we're talking about it on the list last >night, so you should have the posts. As regards the weight of the >hammers themselves, weighing every replacement hammer against it's >original counterpart is not an idle exercise for those with too much >time on their hands. While it's important to get a replacment hammer >that's as close to the original as possible in terms of over-all >weight and molding weight/felt density weight, there are some things >that can be done to the hammer, itself, to alter it's weight, with- >out having to get into changing the weighting of the action, itself. >The whole point of the hammer exercise is to PRESERVE the original >touch, assuming you and the owner think that that's a desirable thing >to do. What could you do to alter, or refine the weight of the replac- >ment hammers? Think about it. Experiment. Tell us what you come up >with. Also, if you came across a piano which had had its hammers re- >placed with ones that were too heavy, short of replacing the hammers, >or reworking the weighting of the action, is there anything else you >might try? Don't try to guess, actually try some things and let us >know what you come up with? > >Les Smith >lessmith@buffnet.net > >On Sat, 22 Mar 1997, Barrie Heaton wrote: > >> Les I don't agree its important to measure the weight of every hammer. >> As there is little you can do to alter the weight of individual hammers >> once you have decided to purchase your particular set. Of course you >> can re-lead the keys, altering the down weights and up weights will >> not only affect repition, but the voice as well. >> >> Also, if we want to be really picky with period pianos. The hammer >> shank has to be taken in to consideration, some early Brimmead pianos >> had oval shaped hammer shanks, with nice little nobly bits behind >> the hammer head. The shape and weight of hammer shanks also plays a >> part in the colour range of a pianos tone this is due to the pianoist >> ability to bend the shank when playing. This will excite different >> harmonics. >> >> Regards, >> >> Barrie. >> >> >> >> In article <Pine.BSI.3.95.970321182103.23080A- >> 100000@buffnet11.buffnet.net>, Les Smith <lessmith@buffnet.net> writes >> >Ah, now you're bringing another factor, voice, into the matter of >> >hammer selection. It's certainly worthy of consideration, and in the >> >process, complicates things somewhat. The weight of the hammer-- >> >measured in grams--is of comnsiderable importance to the touch of >> >the piano. If we're restoring an instrument where we want to pre- >> >serve the original touch, measuring and matching up the weights of >> >both the original hammers and the replacements becomes of primary >> >importance. And it's not just a matter of weighing and matching up >> >the first and last hammer of each section, it a matter of weighing >> >and matching each hammmr. All eight-eight. Now you want to add to >> >that matter of the "voice" of the hammer. Different moldings-- >> >walnut, mahogany, birch, etc--have different weights, and as the >> >density of different felts vary, so too will their individual weights. >> >So the wieght of a particular hammer depends upon BOTH the type of >> >wood used for the molding and the density of its felt. From a touch >> >standpoint, it really doesn't matter whether the hammer's weight is >> >the result of a heavier molding and a less dense felt, or a lighter >> >molding and a denser felt, but the such a selection can have a big >> >impact on the voice of a particular hammer. In other words, it might >> >be the correct weight, but the voice is all wrong. Kind of like your >> >making that Bechstein sound like a Yamaha! Therefore, not only the >> >weight of the hammer is important, but how that weight is achieved >> >in terms of molding-weight/felt density must be considered, too. >> > >> >Les Smith >> >lessmith@buffnet.net >> > >> >On Fri, 21 Mar 1997, Barrie Heaton wrote: >> > >> >> Yes, your on the right tracks. Les and Horace had described density to >> >> you very well. May I add though, the customers requrements should be >> >> taken in to account. I misinterpretered a customers request on his >> >> Bechstine he said it had lost its "umph" my neighbour has a lot of >> >> "umph" His neighbour had a brand new Yamaha which I tune. Which is >> >> very bright and lovely bass. So I assumed he wanted a bright piano. >> >> Boy was I mistaken it took me six months and a loot of visits to tone >> >> those hard hammers down. What he meant by umph he wanted a nicer bass >> >> but he still wanted his Bechstein sound which is a soft mellow treble >> >> compared with a Yamaha. >> >> >> >> Some of the Bechstein Grands start at gage 13 at the top so a dense >> >> hammer is not necessary to produce a quality sound. That's why >> >> personally on grands around the 1920 and down. I tend to go for re- >> >> covering rather than replacing, it is a bit like buying a set of pre- >> >> hung hammers the re-coverer matches the original felt so all you'll have >> >> to do is replace the rollers and re-centrer the hammers plus they are a >> >> little bit cheaper. >> >> >> >> Hope this is of some help. >> >> >> >> Regards, >> >> >> >> Barrie. >> >> >> >> >> >> >> >> In article <09151041200001@DEBCOM.BE>, Peter Kestens >> >> <KESTENS.P@Debcom.be> writes >> >> >PETER KESTENS >> >> >Het Muziekinstrumentenatelier >> >> >BELGIUM >> >> >KESTENS.P@Debcom.be >> >> > To Barrie Heaton, >> >> > >> >> >Could the density of the felt being of any importancy? The higher it is, >> >> >the more it weights? >> >> > >> >> > >> >> >> >> >> >> >> >> >> >> >> >> -- >> >> >> >> Barrie Heaton | Be Environmentally >Friendly >> >> URL: http://www.airtime.co.uk/forte/piano.htm | To Your Neighbour >> >> The UK PIano Page | >> >> pgp key on request | HAVE YOUR PIANO TUNED >> >> >> >> >> > >> > >> >> >> >> >> >> -- >> >> Barrie Heaton | Be Environmentally Friendly >> URL: http://www.airtime.co.uk/forte/piano.htm | To Your Neighbour >> The UK PIano Page | >> pgp key on request | HAVE YOUR PIANO TUNED >> >> > > -- Barrie Heaton | Be Environmentally Friendly URL: http://www.airtime.co.uk/forte/piano.htm | To Your Neighbour The UK PIano Page | pgp key on request | HAVE YOUR PIANO TUNED
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