<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type"> <title></title> </head> <body bgcolor="#ffffff" text="#000000"> Hi Dave I read what he wrote, and replied as I felt appropriately. (friendly tone here just so thats said)  It is not given that you need to change the tension of the spring when you change pinning resistance. You dont know that until you've actually changed the pin and find out.  I tend (try) to keep to the exact subject matter as best I can, and the sequence of posts written that he replied to had one specific reference to changing the spring tension... and that stated to quote: <blockquote> <blockquote>"Whatever friction there is at the lever pin simply restricts the amount of movement of the lever for same spring strength" </blockquote> </blockquote> The subject matter was in other words nicely isolated and I treated it thus.  I went on to point out that if you first did decide to imply that an increase in pinning resistance bore with it a need to increase spring strength... that this was questionable.  It  may... or it may not... depends on how strong the thing was... depends also on whether or not you need to change the hammer center first... depends on other things you need to take care of first as well.... which makes it very complicated to comment on unless one keeps each moment isolated bit for bit. As to your closing claim.. I agree.. you can increase the push on the key without making a hammer jumpy by increasing the tension on the spring and other appropriate adjustments. But this can be done in several ways... and not all of them are equally wise.  The point is, the tension of the spring affects jack travel, hammer lift, and key return, and all these are in turn affected by the friction of their respective centers, and by their individual mass.  And the main point of the whole repetition lever is not to help key return speed... but to raise the hammer and reset the jack well before the key returns full distance.  How fast the key returns in all this in the end is more a matter of pianist preference to begin with then it is anything else.  Some like to feel a bit of a kick from the rep spring... some like none... some like 30 grams of upweight... some prefer closer to 20. Cheers... btw... hows the convention going ?? RicB <blockquote>Ric: </blockquote> <blockquote>You need to read more carefully.  Dean said " If you increase the resistance of the pinning, you must also increase the spring tension to overcome this resistance for a given hammer lift." </blockquote> <blockquote>Of course the spring tension doesn't get increased until you increase it.  The point is you can increase the tension helping to return the key and hammer without making a jumpy hammer. </blockquote> dp   David M. Porritt </body> </html>