[Luke Bellani]

Hi Brendan,
That looks quite nice.

That sinusoidal signal looks like the meshing of the 47 tooth worm gear.

To me it looks like it is contributing about 2 arc seconds p-to-p to the PE.
Maybe the meshing is too tight? Perhaps a slight adjustment of the motor mounting plate may reduce that signal.

From what I can see, it appears that you only have one 8 minute worm cycle and that would makes it difficult to get any reliable idea of the true PE.

I believe that you need about 5 or 6 cycles to get a real representation of PE for your mount.

Well that is what I have been told from others that have a much better understanding of measuring PE than I do.

I think that a belt drive would not exhibit the sinusoidal signal.
Mine certainly doesn't, however there are other noise components that I am working to remove.

I have attached the a screen dump showing the first capture of PE data from my belt drive as analysed by PECPrep.

The data shown is from a PERecorder run capturing seven worm cycles.

The largest signal component is from the 60 tooth pulley on the worm shaft.

I'm hoping that the new pulley will do better.

Cheers,
Luke
P.S. Notice how all the cycles are in phase.
PPS. Sorry, I just noticed that there are two cycles in you graph.