Replies

1. 
   JohnWW | Aug 15, 2006 06:31pm | #1

   Craig,

   Usually the flatness of a fence is measured by placing a straightedge against the fence and then measuring any gaps between the straightedge and the fence with feeler gauges.  How did you set up the dial indicator to measure the flatness of the fence?

   John White

1. 
   craigpw | Aug 15, 2006 10:12pm | #2

   John, I use a TS-Alignment jig which uses a  miter slot  to slides a dial indicator along the fence. The jig also allows the vertical face of the fence to be measured which was .002 in. maximum for my fence.   Craig

1. 
   JohnWW | Aug 15, 2006 11:22pm | #3

   I guessed that was the technique you used, but it doesn't pay to jump to conclusions when you are problem solving. 

   Next question:  The dimensions you gave.004" high and .010 low, are they both on one face of the fence?  In other words did you zero the indicator and then find that the reading moved between .004 to one side of zero and then shifted to .010 to the opposite side as you traversed the face of the fence?  Also were the high and low areas localized, just a small dip or bump, or was the change gradual over the whole length of the fence. 

   Also are you sure that you aren't just reading a misalignment of the fence to the slot, or possibly some flaw in the straightness of the slot itself, which is a risk using your method of measurement.

   John W.

1. 
   craigpw | Aug 16, 2006 06:28pm | #4

   I measured the fence on the left side only. I zeroed the indicator at the front fence and read dimensions as left/minus (.999, .998, etc) and right/plus (.001, .002, etc)  until the miter slot ended. I used both the left and right miter slots to see if there was a difference between them as you suggested. Using the blade as a reference, a difference of .001-.002 in. was seen although not a every long distance. When I measured the fence many times from each miter slot at various distances, the left slot measured .000-.990 in. (left) and the right slot measured .000-.010 in. (right) with a 6 in. distance .004 in. (left).  This suggests I'm doing something wrong. I have used a dial indicator before but perhaps my technique needs some help. Or should I get a good straight-edge?

1. 
   JohnWW | Aug 16, 2006 11:42pm | #5

   I think that using the dial indicator to determine flatness is creating problems.  Using a straightedge for flatness and a square to determine if the face is vertical will yield much more reliable, and understandable, results.

   The face of the Biesemeyer fence probably isn't flat in any case, they all seem to be off by a few thousandths at least, and the design of the fence makes adjustment impossible since the attachment screws for the facing are covered by the laminate facing, a major design flaw.

   John W.