---------------------- multipart/alternative attachment Below you see the first test of side by side magnets with adjustable fold down mounts for the key magnets. I want to refine this idea so that the flange is the key itself, and the shank is sunk down into the key half the diameter of the shank... about a 3 mm deep by 15 mm long routed channel. That will look a bit better methinks, and give even better room. These magnets are Ø5mm by 3 mm thick, and you dont need any more then that as the UW/DW measurements below will show. Mags Down from left to right DW 70 UW 41 // DW 68 UW 47 // DW 69 // UW 50 Mags Up from left to right DW 54 UW 30 // DW 54 UW 39 // DW 54 UW 46 This experiement saw the magnets mounted a good deal more solidly then previous ones, and I was suprised that for these three notes there was a reduction in apparent friction of about 2 grams. The 3.5 gram difference in friction in the middle suggests some influence by the neighboring magnets, and its interesting to see that the effect is apparently something that overcomes exisiting friction and lowers its value by some small degree. Using Ø4 mm magnets would decrease this affect, and would no doubt provide enough effect placed where these were. As is.. with about 5 mm distance between key and whippen magnets, we are getting a reduction in DW of around 15 grams. The whippen magnet was glued on the underside of the jack about 3 mm forward of the jack centerpin. This far out neutralizes the tendency of the hammer to speed up through the bottom half of the keystroke doing the DW test. I think actually, They could be placed just a bit further back ... just behind the jack on the whippens lower arm and still get enough effect while not effecting this hammer travel fully so much. Cheers RIcB [Image] [Image] -- Richard Brekne RPT, N.P.T.F. UiB, Bergen, Norway mailto:rbrekne@broadpark.no http://home.broadpark.no/~rbrekne/ricmain.html http://www.hf.uib.no/grieg/personer/cv_RB.html ---------------------- multipart/alternative attachment --------------457388F5D5ED598FCD5554A2 An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/54/d1/46/7f/attachment.htm --------------457388F5D5ED598FCD5554A2 A non-text attachment was scrubbed... Name: C:\\DOCUME~1\\RICHAR~1\\LOCALS~1\\Temp\\nsmail5J.jpeg Type: image/jpeg Size: 41082 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/42/a4/e6/40/nsmail5J.jpeg --------------457388F5D5ED598FCD5554A2 A non-text attachment was scrubbed... Name: C:\\DOCUME~1\\RICHAR~1\\LOCALS~1\\Temp\\nsmail5G.jpeg Type: image/jpeg Size: 41326 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/8a/e7/31/a3/nsmail5G.jpeg --------------457388F5D5ED598FCD5554A2-- ---------------------- multipart/alternative attachment--
This PTG archive page provided courtesy of Moy Piano Service, LLC