Meade SN6 Focuser

[B]
I bought an old Meade SN6 from an Astromarter. It had a terrible helical focuser that was balky and frustrating to use. My intent was to eventually give this scope to my son and grandchildren. But they would have quickly lost interest when trying to fus with that old focuser.

I could have gotten a more modern replacement focuser from GSO, but I elected to get one from the Crawford Machine shop to support home-grown craftsmen.

Dan, the man at Crawford, planned to use the mounting base from the old focuser for the new one. Dan said he can make me a 1 1/4" focuser with no problem. But a 2" focuser is proving problematical because there's no way to get the screws and nuts on to mount the new focuser without removing the corretor lens.

So I have a few questions for any users of Meade SN telescopes. How would you install a new focuser?

How difficult is it to remove the corrector lens and get it back on properly.

I'd appreciate answers to these questions soon, because Dan is waiting for me to tell him how to proceed.

Thank you in advance.

Steve Gaber

Hi Steve, I did exactly what you're proposing to my SN6. If it's got the helical focuser (good riddance), it may be an LX55. My LX55 had a phenolic tube, not metal; it makes a funny kind of rap when you tap it, not metallic at all. You can easily drill through the stuff, so making new holes for Dan's focuser is easy. But be careful and go very slowly once the bit tip penetrates the wall. That phenolic will "give" and inner wall fragments will break into the tube and leave a ragged hole. Slow works like a charm. Then use a Sharpie to mark a tiny dot on the corrector glass right at the edge, and another on the tube, so you can get the corrector on exactly where it was before. Don't try to remove the complete corrector housing ring from the tube. The 6 screws attach to nuts inside the tube that you can't refasten with the corrector in place. Remove only the corrector and secondary unit using the allen screws in front. You can do the job horizontally on a soft, fluffy (clean) bath towel in case anything slips. However, there are small cork shims that cushion the corrector against the ring which need to go back exactly as they were before. Hence I did the removal with the tube vertical. I took the occasion to completely rehab the scope. I removed the primary & cleaned it up, marking its position with a Sharpie as with the corrector in case the secondary got rotated during the work. I also Protostar-flocked the tube, and bolted on a Vixen-style dovetail. Cleaning the optics is not a frightful procedure as long as you're slow, careful, and use the cleaning methods described in other threads here. My rehab turned the scope into one of the handiest, most enjoyable scopes I've ever had. Tack sharp stars to the edge, nearby GCs resolved to the core, and low-power sky-sweeps that took my breath away no matter how many times I'd seen the area before. The SN6 is perfectly sized to cradle in your arms as you sit on a chair and sweep the skies. You can hold it this way quite steadily up to about 80x but you probably won't go there very often anyway. Using a 30mm 80º eyepiece (25x) and a good clear night, you'll see the skies as you never have before. Later I added some drawer-pull hand-holds to the tube to turn it into a dedicated lap scope. Looks like a snowmobile on training skis, but improved steadiness dramatically. With a Crawford riding up front, it'll be a great scope no matter how you use it. Good luck!

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Finally, the bolts are out. The problem was solved, but not by me.

Since there are no longer any telescope repair shops in this area, I had the idea to see if a machine shop could help me. No machine shops wanted to take on the job.

Then I had a stroke of genius: a gun shop! they work on rifle scopes, so why not?

I found one, the guy did the job in 15 minutes for $10. Fantastic.

There were two reasons why I couldn't get those bolts out.
1. They were not 2mm Allen bolts. They were Star-headed bolts, which was difficult to see. I messed up the heads of two of the bolts in my attempts to remove them with an Allen wrench. The gunsmith had to drill those two out.

2. The bolts had embedded themselves in the cheap-ass plastic hold-down ring, which I thought was aluminum.

After finishing grading my exams and papers I will proceed with the installation of the focuser.

Thanks for your support on this issue.