Hi All,

As per J444,3.1.1.1 and 3.1.1.2, the shaking speed shall be 270 to 300rpm and taps per minute shall be 140 to 160.

Would like to know how to calibrate the Ro-tap machine to NADCAP standard? As J444 is a requirement and there's no standards detail the Ro-tap performance.

Calibration has also become the local site responsibility.

Thanks!

I can only offer minor insights since I have never had to perform Nadcap audit for Ro-tap machine myself. I presume you would use stop-watch to measure the taps/minute and some form of calibrated (i.e. certified) tachometer for the rotation speed. I understand that the timer must also be calibrated/certified. The screens must also be certified (available from manufacture).
Perhaps someone with more Nadcap familiarity can help with this answer.

Jack has it right. Calibration can be done internally if instruments are traceable to National standards or can be done externally by qualified source.

Hi Jack & John,

Thanks for the insight. The timer is calibrated via a stop-watch and the rpm is calibrated via tachometer. Both masters are traceable to certificate of conformance.

The issue I had now is the taps per minute. Is there any equipment/gage available to count the number of taps?

Thanks!

The Ro-Tap has specifications of 280 rpm +/- 10 sieve rotations and there are 150 taps/minute +/- 5 taps. The most common used sprocket has 14 teeth and the timing belt pulley has 87 teeth. By taking the actual rmp of the motor and multiplying by 14/87, you should get the actual rpm of the Ro-Tap. I.E.! 1750 x 14/87 = 281.6 = 282 rpm There are 29 teeth on the timing belt pulley hub and 54 teeth on the cam gear. 282 x 29/54 = 151 taps per minute R-30015 timing belt pulley w/hub R-20039 cam gear R-10070 14-tooth sprocket