Tolerances for Grinding Laminations

[SenterShot]

I'm having a sled made to grind tapers and the question of accuracy/tolerances came up. How perfect do tapers (or parallels for that matter) need to be? If the typical taper is .002 / inch, will a few thousandths off in the middle of a limb make a noticeable difference? How much is too much variance?

[Crooked Stic]

Depends on what you are building. You can get by with more on a longbow than a curve. Make sure you sled is accurately machined. Adjust your sander as close to perfect as possible. Some say .002 side to side. I like it closer. You can flip the lams on each pass when getting close to you target thickness. And don't rush things. Learn your machine and you will do well.

[kennym]

A few won't make a lot of diff, you can tiller with the edges of limbs to get the profile you want. That said, the more accurate you can get em the better!  

[LittleBen]

x2 what's been said. The thicker the stack, the less it will matter.

Also, I know that my sled is not that accurate, so what I do is I stagger the lams ... So if I'm making a 60" bow, one set of lams gets the thin ends cut off, and the next set of lams gets the thick end cut off then spliced ... that way I don't have two thin spots on top of one another amplifying the problem.