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Old 11-07-2025, 01:32 AM
Leo.G (Leo)
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Leo.G is offline
 
Join Date: Nov 2016
Location: Lithgow, NSW, Australia
Posts: 1,614
EASY disassembly of stubborn screw together focuser bodies

I have an 80mm Megrez original model semi APO refractor, everything on the telescope is standard.
I've recently noticed excessive slop in the original focuser and worn (binding) bearings on the slide (693ZZ, $1.80 each) and do have another very nice Williams Optics focuser which should go on with minimal fuss but I'd like to shim/modify the original and have it with minimal slop in the extended position with a lot of weight where I use it for my photography with my full frame Nikon D810.


In struggling to unscrew the body sections my son took it out from where I was cursing, ran to the kitchen and got a silicon jar opener with varying sizes for different lids, clamped it on one section then had to find something to grip the main body to try and unscrew it. He ended up grabbing one of my exercising resistance bands (blue if it makes any difference) and WOW, how easy was that, the resistance band griped the body like my chain strap wrench (chain wrench) would without the damage (last resort for this type of job, fine with most mechanical tasks).
Another part of the body had been locked onto the main thread with 3 Allen head grub screws and one straight blade head grub screw, The 3 Allen head grubs were not particularly tight but the straight blade unit was excessively tight. All of these grub screws had chewed into the primary 68mm thread they locked onto on the tube. The handy resistance band came into play again gripping both parts with my son turning one end and me turning the other.

I'll clean the threads before I reassemble the unit but we've just found it's a GREAT way of holding these things without slip and so cheap at Aldi and other places (when Aldi have them).


I'll be using resistance bands in future for these hard to grip items (and numerous others when a chain wrench and an 8" Record bench vice (or 12 inch milling machine engineers vice just aren't suitable due to the damage they will cause.
If I had bought them at K-Mart it would make the news and become a life hack (no, don't get me started on the stupidity of these idiots discovering things our grandmothers did for centuries and all of a sudden common sense becomes a "life hack" discovered by some over paid/sponsored influencers.


Influencer used to be another word for unemployable hack.
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