Replies

1. 
   JeffHeath | Dec 31, 2004 05:52am | #1

   rustum

   I saw it posted here just last week.  Check the archives.

   JC

2. 
   Elcoholic | Dec 31, 2004 10:34pm | #2

   Here's one:

   Percent of spring back  = 100 X [1÷(N²-1)]  where N = the number of laminations.

   John O'Connell - JKO Handcrafted Woodworking

   The more things change ...

   We trained hard, but it seemed that every time we were beginning to form up into teams, we would be reorganized.  I was to learn later in life that we tend to meet any new situation by reorganizing; and a wonderful method it can be for creating the illusion of progress while producing confusion, inefficiency, and demoralization.

   Petronious Arbiter, 210 BC

1. 
   riff | Dec 31, 2004 11:39pm | #3

   Here's another, perhaps handier.springback = R /( N2 - 1 )where R is the form's radius and N is the number of laminations

1. 
   UncleDunc | Jan 01, 2005 12:09am | #4

   Is N2 supposed to be N squared or N times 2?

1. 
   riff | Jan 01, 2005 12:48am | #5

   N squared, I don't know how to enter the little 2. :)I've not yet had a chance to put this formula to use but the results seem pretty reasonable.

2. 
   rustum | Jan 01, 2005 02:01am | #6

   thanks

3. 
   Jamie_Buxton | Jan 01, 2005 05:30am | #7

   Riff ---

     I've seen that formula too.   However, I don't understand what this springback is.  For instance, is the difference in the radius from the form's radius?  Or is it something else?   Could you make a diagram which clearly defines this?

1. 
   riff | Jan 01, 2005 08:11am | #8

   Hi Jamie, you've got it. As you said "the difference in the radius from the form's radius" or put another way the form's radius + spring back equals the final radius of the laminated part.

3. 
   RickL | Jan 03, 2005 03:47pm | #9

   http://www.woodweb.com/knowledge_base/Calculating_Springback.html

   http://www.woodweb.com/cgi-bin/search/search.cgi

   A visual to go with it. Most of the answers are already out there if you know how to search. Thinner plies and a harder gue will eliminate the problem as well.

   
   

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   Edited 1/3/2005 7:49 am ET by rick3ddd