Topic: Tair 3A 300/4.5 dismantling
If you have not attempted to dismantle a lens before then I would suggest that you do NOT start with one of these !
First step, remove front lens housing:
If you are only cleaning the lens then clean the rear lens in situ, ignore the bit about removing the rear cover tube
(the bit with the tripod mount on) and just remove the lens mount and rear light baffle for easier access.
If you want to clean and re-lubricate the focussing threads then most of the thread can be accessed by sliding the rear cover tube forwards.
You can now clean and lubricate most of the thread and you may not need to dismantle any further.
If you want to completely dismantle the focussing screw then you will need a special tool.
I attacked an old spanner with my angle grinder and made one in about 15 minutes,
the handle has to be offset as you have to put it in at angle to reach inside the tube.
If you want to completely unscrew the focussing mount there is now nothing to stop you, otherwise do NOT turn it.
I had to remove mine because someone had attempted to lubricate the lens by putting oil down the end of the rear
cover tube, all this did was to make the felt seal swell up and make it all even stiffer.
That's it, when putting it back together you will have to make sure all parts go back to exactly the original positions
because all the grubscrews locate into pre-drilled holes on the threads and if you don't get them right they stand out
above the surface.