Several weeks ago I removed these three items from the Meade ETX-70AT telescope in preparation for tearing it down:

That’s the focusing knob, and the tripod bolts. I put them in a “safe place” so they would not get lost, but once I got around to tearing the telescope apart and putting it back together, do you think I could find them? Spoiler alert: No, I could not find them.

I’ve spent countless hours over the past week looking for these, only to come up empty handed each time. Then this morning, as I looked for a completely different item, there they were, sitting in a drawer I had looked in at least three times. Never fails. I spend more project time looking for things I know I have than I actually spend on the project itself.

Every. Damn. Time.

So back to the project… Over the course of that week, I decided that the stock focusing knob has two fundamental flaws that needed to be addressed. First off, the knob is just way too small, which makes fine focusing difficult. Secondly, it’s right up on the back of the telescope next to the eyepiece housing, and gets harder and harder to get at as the telescope is pointed higher. In fact, it is impossible to get at when the telescope is anywhere near straight up.

I have a two part plan to alleviate this. First is a replacement knob which I 3D printed from an STL file I found on Thingiverse:

As you can see, it has a much larger diameter which should make fine focus much easier. This particular knob was designed for the ETX-125, and is actually too big for the ETX-70, as the eyepiece housing is in the way, but that’s OK as it leads right into part two of the plan, which is a flexible shaft extender which will move the knob out past the eyepiece, and should make focusing easier when in vertical orientation. There’s a guy selling one on Amazon for $9.98, but I’m thinking I can fabricate one for much less after a visit to my local Ace Hardware.

To be continued….