Indexing with VFD. Best practices? Alternatives?

I would look into a Camco indexer and the clutch / brake mentioned earlier - likely you will need an inline reducer as well (some units may provide this already). These things provide a sinusoidal motion profile and are designed for just such an application.
 
Is it beyond reason to up-size the VFD higher than the motor, so that the VFD has enough power to decel without error?
DB resistors would help as well.
 
Now that we know "the REST of the story", I have to agree with DickDV. You are trying to accomplish a Servo function without using a Servo and although there is SOME leeway in what a VFD can do, and you can oversize the VFD if you have to, an induction motor is NOT made to accomplish this. The mass of the motor itself is going to become a limiting factor, and if you increase the motor size to get the added torque necessary, you are ALSO going to increase it's mass and inertia. It quickly becomes a game involving the laws of diminishing returns and at some point, probably now, it is going to get you into a corner where you can only get out by switching to a servo system, but AFTER you have bought and tried the induction motor then found that it failed.

If you were not aware, Rockwell offers a free Motion Analyzer Tool, either as a cloud based program or you can download it to run independently. You enter your mechanical properties and required movements, and it picks out the servo and drive you need to get it done. You have to register, but there is no cost.
http://ab.rockwellautomation.com/motion-control/motion-analyzer-software#overview
 
Per Archie's and Jesper's suggestions

As Archie and Jesper have suggested, this may not be the best application area for a VFD, or even servo drive.
I would investigate using a wrap spring clutch, also known as a single revolution clutch.
Several manufacturers offer a package that will index a full or partial revolution per input.
 
There is a crude (relative to servo) positioning function built into the new PowerFlex 525 that is specifically intended to fill the gap between simplistic VFDs and servos. I've used, it's surprisingly good. It needs an encoder on the motor and an encoder card added to the drive, but it is very simple to implement.

Going to a synchronous motor will not really buy you anything.

Hey, it's an old post, but can you or someone explain a little more details on how to do indexing. TIA
 
What is the mass that has to be indexed this way ?
If there is no variation to the indexing, why even consider an electrical solution ?
I bet it can be done purely mechanically.
Check out "geneva mechanism": http://en.wikipedia.org/wiki/Geneva_drive

We use this quite often, and it is excellent solution, as you do not need to brake during process just at the end of process in order to stop at precise position. We use it with classical U/f drive with encoder and magnetic brake and gearbox. If you do not need to change speed of motor once you have obtained the effect, there is even no need for drive. Disadvantage is that is costly to build Geneva drive if is not done in series...
 

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