Polar scope - O-ring to stop small optics wobble inside

It's been a year since I decided to buy a scope and begin to explore the heavens. I must admit that it was a great year, got pretty far with gaining experience using the scope equipped with a dslr and how to capture different objects with different imaging methods. Eventually I had my first photos of planets, meteor, Moon and ISS. So I love my Skywatcher Explorer 200PDS+EQ-5 mount.
But still there is one thing I couldn't sort out yet. Polar Alignment... Slowly becoming my nightmare, tried many many different ways, watched tutorials etc.
One thing became soon clear, if I do everything the right way than there must be something wrong with my equipment's settings. I had an attempt to remove the polar scope, but only the bottom part came off (small piece of optics with Cassiopeia and Big Dipper on it). After that whenever I turned the RA axis around whilst looking through polar scope the little optics in the polar scope was wobbling, making polar alignment impossible.
Later I've been told they put a rubber O-ring in between the optics and the small tube, as optics inserted the O-ring keeps it right at a good fix position.
Of course it was probably one little step to resolve the misery of my polar alignment issue, but this might be useful for someone.
My big question was the size of the rubber ring. I did my researches on that but found no answer on exact parameters.
Well went into a DIY store, bought 5 different size of O-rings I thought might fit the requirements and luckily one did. I had to acknowledge the wobble has stopped.
Hopefully one problem less...

Inside diameter 18.0mm
Section               3.0mm

 

 







This video I found and is a perfect explanation of this problem. By the way many good videos can be found on youtube under name Astronomyshed, same gentlemen who's in this video too.
From 2:30 becomes interesting.......

Again an aircraft crossing Sun

It seems like these are my lucky days. I just set up my camera, start shooting a movie and bang there's a plane in front of Sun. I actually changed location as moved to another part of London, so that's the only reason I can think of to be so lucky recently.... anyway here is a nice photo and a gif of the whole event.
This must be a small aircraft, most likely an Airbus 320 or a smaller Boeing I recon.

 Here comes the Sun, outdoor photo with sun spots on its surface

Indoor photo (not as sharp as the one above plus it is on frame of an HD video)

and the gif from the actual video - 24 frames so nearly one second (as my dslr records 30fps)

As aircraft crossing Sun

During yesterday's attempt to take a nice shot of the morning Sun with huge sunspots on it, I realized aircrafts are keep crossing the disk. So after a few photo I changed my camera settings to video mode and started to shoot a couple of videos. And than it happened, pure luck I guess...

ISS in the past year

It's time for some summary.
So far there were four occasions when I was able to take shots of the International Space Station.
Here they are in chronological order:

08.06.2013

13.08.2013

20.10.2013

27.12.2013

Venus

Yesterday at ISS hunt I had an approximate half an hour till 17:11 ISS pass. It was a bright clear sunset, Venus was such an obvious target to spent some time with. Although the air was shaking due the harsh wind blowing from east , when I set the controls to the heart of Venus :) the surprise came. 

I really never spent time on Venus, probably once but luckily it was a full Venus than. So never assumed a crescent Venus exists.

Than I realised how dumb I am, of course there is a crescent Venus. I found this drawing on twitter. It explains why we see the Venus the same way than we see our Moon, in different phases.

It also explaines why will Venus become from a sunset object to a sunrise object. Soon it disappears as it positions itself in-between Sun and Earth, just like Moon does. Of course Venus and Moon has a different orbit and motion relatively to Earth, but still the way they are lit is similar and results similar visual experience.

So see you Venus in the morning skies on the 11th January....

ISS today

Today's try on ISS reminds me how hard it is to capture a fine sharp image of it. Not my best attempt but still some details are visble. Also some photos below attached.

Over 7100 frames captured, but my guess is that the sharpness wasn't the best at all. I've done this a few times and this amount of frames should have a few very good one. 

To be honest ISS appeared at its highest of 35º so because of its distance that might be result of my lost sharpness. Anyway it was a lovely evening and I did not come home empty handed :)))

The gif below shows its journey from west towards south-east. When it first appeared, coming from west just after an hour after sunset, Sun still reflecting on the solar panels. But as it kept moving into the direction of the dark side of Earth, less and less sunlight reflected back towards my eyes so less and less is visible from ISS from my location. By the end of the gif - approximately 2:30 mins - the solar panels disappeared completely.

Let's add that the whole duration of ISS's crossing the sky was roughly 6 mins but due to low clouds I couldn't continue shooting. 

A gif of 14 frames which I think has something to show -
during the journey it took in 2:30min crossing the sky.

The very first useful frame, probably the best with all four solar panels

Because of its orientation - I guess - already two of four solar panels are dissapeared

Jupiter with surprise

I managed to capture the Red spot and the shadow of one of its moons Europa.