<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:st1="urn:schemas-microsoft-com:office:smarttags" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv=Content-Type content="text/html; charset=us-ascii"> <meta name=Generator content="Microsoft Word 11 (filtered medium)"> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PlaceName"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PersonName"/>  <style>  </style> </head> <body lang=EN-US link=blue vlink=purple> <div class=Section1> You have my interest guys, with all this careful work.<o:p></o:p> <o:p> </o:p> However, what about the effects of uneven string-height on strike-line? A capo cast or ground 3mm higher at one end is just as deadly as a gluing a hammer on 3mm off line. And although a hammer offline by an 1/8th” (3mm) would certainly catch your eye, a deviation in string height of 1/8” is not all that uncommon. <o:p></o:p> <o:p> </o:p> (I’m needing at least one person to agree that missing strike by a mm would have “at least” as much impact as a shank that is .2g off target weight! :>)<o:p></o:p> <o:p> </o:p> The only two factory scale designers I’ve discussed this with assert that the strike point is the first line they draw, and that it is most certainly “straight.” <o:p></o:p> <o:p> </o:p> (my only other point of reference is a fairly vivid imagination, and I can’t “imagine” them drawing it any other way... can you?)<o:p></o:p> <o:p> </o:p> When the capo is curved, I’ve always believed (okay... assumed) that this was a deliberate compensation designed around a straight strike-line, in order to accommodate the arc and placement of the bridge, not to provide a template for our hammer-line. (Correction welcomed)<o:p></o:p> <o:p> </o:p> In any case, I would want proof in the form of speaking length measurements before going wavy with another hammer-line, having unglued/reglued my own work onto “shortened” shanks more than once.   <o:p></o:p> <o:p> </o:p> Question #1:<o:p></o:p> <o:p> </o:p> So, if the strike line you set “by-ear” ends up being a little crooked, and uneven string height is the culprit, why not vary the bore-length?<o:p></o:p> <o:p> </o:p> A wise and valued supplier who I turn to for pre-hungs when things get “bizzy,” will not do this for me. His claim being that moving mass further in/out on the arc will have more detriment than anything I’m trying to correct. <o:p></o:p> <o:p> </o:p> (I trust his knowledge, but have to temper it with the reality that having to graduate bore-lengths would also slow ($$$$) down his operation ;>)<o:p></o:p> <o:p> </o:p> Question #2:<o:p></o:p> <o:p> </o:p> So wouldn’t moving the hammer in/out on the shank do exactly the same thing?<o:p></o:p> <o:p> </o:p> Question #3:<o:p></o:p> <o:p> </o:p> How does the Stanwood approach deal with moving the Sumo further in-out on the see-saw?<o:p></o:p> <o:p> </o:p> Thanks all, I always appreciate your wisdom.<o:p></o:p> <o:p> </o:p> <st1:PersonName w:st="on">Mark Cramer</st1:PersonName>,<o:p></o:p> <st1:place w:st="on"><st1:PlaceName w:st="on">Brandon</st1:PlaceName> <st1:PlaceName w:st="on">University</st1:PlaceName></st1:place><o:p></o:p>  <o:p></o:p> <o:p> </o:p> <o:p> </o:p> <o:p> </o:p> <o:p> </o:p> <o:p> </o:p> <o:p> </o:p>  <o:p></o:p> <o:p> </o:p> <o:p> </o:p> <o:p> </o:p> <o:p> </o:p> <o:p> </o:p> <o:p> </o:p> <o:p> </o:p> <o:p> </o:p> <o:p> </o:p>   <o:p></o:p> <o:p> </o:p> <o:p> </o:p> <o:p> </o:p>     <o:p></o:p> <o:p> </o:p> -----Original Message----- From: caut-bounces@ptg.org [mailto:caut-bounces@ptg.org] On Behalf Of Jon Page Sent: February 15, 2008 9:05 AM To: caut@ptg.org Subject: [CAUT] hammer line <o:p> </o:p> I weigh shanks and separate them into piles to the .1 g.<o:p></o:p> Then I measure the height of the knuckle, measuring<o:p></o:p> the shank too (the shank width variance is negligible)<o:p></o:p> but the knuckles are not always pressed in the same.<o:p></o:p> So I further break down each weight pile into three groups:<o:p></o:p> low, med, hi.  I try to keep the variance within .010" (.25mm)<o:p></o:p> and set aside ones out of the 'window'.<o:p></o:p> <o:p> </o:p> I weigh the bored/tapered heads and plot their weights on a chart.<o:p></o:p> <o:p> </o:p> According to the hammer weight, I'll select the appropriate weight shank<o:p></o:p> to achieve as smooth of a SW curve as possible bearing in mind knuckle<o:p></o:p> height groupings to place the med's more central and the low's and hi's at<o:p></o:p> the extremes, screwing the shanks to the rail as I go.<o:p></o:p> <o:p> </o:p> Grouping like-height knuckles leaves a more even let off button line and<o:p></o:p> one less variable with note to note wippen/shank vertical placement<o:p></o:p> (I know there's a better word for this).<o:p></o:p> <o:p> </o:p> By assigning a specific weight shank to a hammer weight less SW adjustment<o:p></o:p> is needed at the end of the process, ie; if the hi bass weighs 9.5 and the low<o:p></o:p> tenor weighs 9, using the same weight shanks will leave the .5 g difference.<o:p></o:p> But if you place a 1.7 g shank with the bass hammer and a 2g shank<o:p></o:p> with the tenor you will come out with 11.2 and 11, respectively.  Depending<o:p></o:p> on the availability of sizes, you can strive for the same weight or a <o:p></o:p> .1g difference.<o:p></o:p> <o:p> </o:p> I then install the hammers and let dry, then remove them from the rail.<o:p></o:p> Next is to cut the shank protrusion off with a band saw and rough cut the arc.<o:p></o:p> Cut all tails to a even length ( I order longer moldings to accommodate a<o:p></o:p> tapered bore) and sand the tails to a 3" arc. This produces a nice <o:p></o:p> finished edge.<o:p></o:p> Arcing removes about .3g.<o:p></o:p> <o:p> </o:p> Now comes the final weigh off. Usually only 12 to 18 need addressing.<o:p></o:p> I precut the hammer leads so I only need to look at the graph to install the<o:p></o:p> appropriate lead. If material needs to be removed. I'll first look at <o:p></o:p> the front side<o:p></o:p> of the cove to remove a few tenths with a Forstner bit.  I order sets uncoved<o:p></o:p> as well; so as not to be hindered in the arcing process with a deep cove. The<o:p></o:p> cove removes so little weight, it is not worth the effort in the <o:p></o:p> scheme of things.<o:p></o:p> <o:p> </o:p> FInally, easing the rear edges and bottom of the tail with a file. Reinstall.<o:p></o:p> -- <o:p></o:p> <o:p> </o:p> Regards,<o:p></o:p> <o:p> </o:p> Jon Page<o:p></o:p> </div> </body> </html>