In Conclusion
  The new block lived up to my expectations in ease of installation, adjustments, and performance. Oh yes, and the 21st century V2 look too. At first the results had me concerned because of a new peak but realizing that with a new block design comes a new method of installation and adjustments due to the Ruland disk coupler used in place of the Oldham coupler. There were no instructions with the unit and as intuitive as the installation may look, worm to gearbox alignment is critical to remove the 'pulsation' felt when manually rotating the worm where the previous Oldham coupler was more compliant in self adjusting though you could still be out of alignment. Once the alignment was perfected the performance improved and exceeded my expectations as can be seen below with the before and after profiles. And because the 76 sec error has shifted to a fundamental frequency (80 seconds) it was successfully reduced using PEC programming.

   Coupler Design- If you are a diehard and want to use the Oldham coupler you need to get a longer gearbox drive shaft otherwise you will have to use the Ruland coupler that came with the new worm block. The test results of the Oldham and Ruland couplers show that both perform equally well when properly aligned so there is no advantage of staying with the Oldham coupler.

So, getting back to my original expectations:

Is the upgrade worth it? Yes, and it improves the G11 performance noticeably as demonstrated in these before and after measurements.

Before - PE profile with the stock G11 worm assembly with the high precision brass worm and no PEC fitting applied
Note that there are no drift fitting applied to these before and after results to purposely show the raw results. Most graph examples posted on the web have them applied and the numbers appear much lower.
After - PE profile with the new one piece worm block using the original brass worm and no PEC fitting applied. While the slopes between the old and new designs look similar (same worm), note the Y scale between the two. The new block results scale is only +/- 4.7 arc seconds.

© 2010 Michael A. Siniscalchi