"Y" axis problem

["joe bury" <joebury-at-hotmail.com>]

List,
  I'm working on a two axis wood routing machine. It has a stg8 model 2 
card. Each axis is driven by a rack and pinion. Each pinion is driven by a 
series of two cog belts.
  I have an encoder with a resolution of 2048, but it has to travel about 
three and a half inches to complete one revolution. This gives me a 
resolution of about 585 per inch.
  On the "x" axis the encoder is coupled with the cog belt drive. This axis 
work fine.
  On the "y" axis the encoder has it's own rack and pinion making it more 
accurate as far as the Poisson of the router. My observation is that emc 
sends the dac a signal and before the amp can ramp up and move the axis 
enough to get some encoder counts it gets get a fowling error. After that 
the emc releases control of the axis and there is a small hop of the axis.
  I have hooked a meter to the dac so that I could watch the signal. I have 
applied voltage in place of the computer to the dac and the axis and encoder 
run smoothly.
  This machine was designed to move quickly three horse power on each axis 
and with out a high degree of accuracy. I may be way off on these 
observations but in any case I think you can get the idea of the problem.
  I would appreciate any input on this matter,I have no idea on what to try 
next.
                                              Joe


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