Fadal Spindle Motor Encoder

 One of the most common problems with a Fadal Spindle Drive running in the Vector mode is caused by the spindle motor encoder. Missing encoder pulses will basically confuse the drive and cause vector miscalculations which result in too much current output to the motor. One sign is that the load meter will usually “peg” or pulsate. Another sign is the RPM will not be stable. Too often the drive is misdiagnosed as being “bad” when it’s actually the encoder causing the problem.

The best method of testing a Fadal Spindle Motor Encoder is to use an oscilloscope to view the A/B channels. Pulse errors can easily be detected. With our new Baldor H2 drive, we simply switch the drive into open loop Inverter mode and you can see the encoder RPM calculations changing erratically with the drives diagnostics feature. With the older Baldor drives, as you rotate the spindle, the drive keypad will display the calculated rpm.

One simple way to manually test an encoder is by using a FLUKE meter, set it to AC input. When checking from the encoder supply power common to one of the A+,A-,B+,B- encoder signals on the spindle drive encoder input terminal, you should see approximately 2.8 VAC when turning the spindle at the orientation speed. The digital pluses look like an AC voltage to a FLUKE meter.

Another important way to test the encoder is by checking the state of each channel. With a voltmeter in the DC setting, from the encoder supply power ground to the A+ encoder input, you should measure either 0 or 3.5 VDC. The state is either high or low. If A+ is high (3.5 volts) then the A- channel must be low; A+ and A- can never be the same. The same logic goes for the B+ and B- channels. If you rotate the spindle and let it stop, you should see the states changing.

When you buy from us, you’re not just getting a “Part In A Box!”

Here are four key examples of the Total Support our customers receive:

1) Diagnose – Direct help in determining if you really do need to replace the part. Based on experience having worked as part of the engineering team that originally designed the Fadal machine parts, our knowledge helps us determine if there’s other elements in the system that need to be addressed before replacing the part.

2) Documentation – We provide very simple and concise information on this site on how to install and get your replacement in and running.  With our documentation, we also include Preventative Maintenance tips to help avoid future failures.

3) Warranty – Just like “the old days”, we value our relationship with each and every customer.  We are driven by fairness and committed to your satisfaction. 

4) Support – With the combination of our Fadal Engineering background and direct interaction with suppliers engineers, you are getting the absolute best product support possible at installation and beyond.

Why buy something from someone without the Fadal engineering experience and the replacement part manufacturer’s direct support?