Secondary Mirror Mod

[Benjamin]

“‘Allo again”

Just wondering if others have done this Astronomy Shed secondary mirror mod?

https://youtu.be/MUE8fxqH3Qc

I’m keen to give it a go on my Skywatcher 8” Quattro as it’s been over tightened by me in the past (have Bob’s knobs already inserted in the secondary holder) and its now hard to adjust easily without a bit of jumping around (much time spent iteratively auto-collimating and recentering). Part of me thinks a whole new spider and secondary holder might be a better solution (say a TS Monster Spider) but also keen to hear of other possible solutions. Any advice welcome! If you have tried it and have a spare but of Teflon sheet or a 35mm OD 10mm ID washer...

[RyanJones]

Hi Ben,

I have done this mod in the past with an older 2nd newt that I had which had developed these indentations over time. I simply used a nylon “ panel washer “ the same size as you have described. It worked a treat and made it much easier to collimate without the secondary shifting back as I locked it off.

Cheers

Ryan

[glend]

Sorry, I had to laugh. I need a translator for that video.

[Benjamin]

Ha, he does some great videos! Less glam than some perhaps.

Will give the Nylon washer a go too. Have the stainless steel washers anyway as a staring point :-)

[Hedworx]

I tried it and it all went swimmingly, can thoroughly recommend it

[Benjamin]

I’ve got a nylon washer version up and running which has made collimation much easier. Have some PTFE sheet on the way to give the metal washer version a go later :-)