6 replies to this topic

[Optics Patent]

I decided to test Grok with a simple question like we have here. I see that it is likely to put the helpful people here out of business! (I note that it missed the key point about the Barlow being engaged while in finder mode).

Q: I’m having trouble getting my Questar telescope to focus. No matter what I do with the focusing know I can’t get it to focus

A: If your Questar telescope (likely a 3.5” Standard or Duplex model) won’t focus despite turning the focus knob, here are some steps to diagnose and potentially resolve the issue, based on common problems reported with Questar telescopes:
1 Check Finder vs. Telescope Mode: Ensure the selector lever on the control box is set to telescope mode (usually vertical or fully to the right). If it’s in finder mode, the focus knob won’t adjust the main telescope’s focus, and you’ll only see a blurry image through the finder.
2 Inspect Knob and Shaft Connection: Verify that the focus knob is securely attached to the focusing shaft. A loose grub screw in the knob could mean the shaft isn’t turning when you rotate the knob. Check if the knob feels loose or spins freely without resistance. Tighten the grub screw if necessary using a small screwdriver.
3 Examine Mirror Movement: Look down the front of the telescope tube while slowly turning the focus knob. The primary mirror should move smoothly forward and backward. If it doesn’t move, the focusing screw may have detached from the mirror arm. This is a known issue and can often be fixed by:
◦ Unscrewing the main tube from the control box (it may be tight, so use steady force).
◦ Checking if the focusing screw is disconnected from the mirror arm.
◦ Reattaching the screw if detached, following guides like those on the Questar Zone (referenced in forums). This is a relatively straightforward fix for someone mechanically inclined but requires care.
4 Assess Focus Range and Resistance: Questar focusers have a wide range (up to 50 turns between close focus at ~10 feet and infinity). Turn the knob slowly through its full range to see if focus emerges. You should feel light resistance at the extremes but avoid forcing it. If the knob turns without any effect, the internal threads (especially in older models with a Synthane rear piece) may be worn, preventing mirror movement. This would likely require professional service from Questar.
5 Check for Image Shift or Optical Issues: If the mirror moves but the image remains blurry or shifts significantly when focusing, you might have a “focus shift” issue (normal to a small degree, about a Jupiter diameter, but excessive shift indicates misalignment). This could require factory adjustment. Also, ensure the optics are clean and free of significant dust or coating degradation, though this is less likely to prevent focus entirely.
6 Try Different Eyepieces and Barlow Settings: Use the lowest power eyepiece (e.g., 24mm or 25mm) and ensure the Barlow lever is disengaged (out of the optical path). Higher power eyepieces or an engaged Barlow make focusing harder, especially if the system is misaligned or you’re bypassing the narrow focus range.
7 Test on a Bright, Distant Object: Point the telescope at a bright, distant target (e.g., a streetlight, the Moon, or a bright star like Jupiter) to make focusing easier. Start indoors with a well-lit object like a dollar bill on a wall if you’re struggling outside, as Questar recommends. If you still can’t focus, the issue is likely mechanical rather than user error.
8 Check Model and Age: Older Questars (pre-1964 or with Synthane rear pieces) are more prone to worn threads or detached screws. If your scope is an early model, the Synthane threads could be stripped, preventing mirror movement. Note the serial number and year (if available) when contacting Questar for support.
Next Steps:
• If the mirror isn’t moving or the screw is detached, try the reattachment fix described above. Refer to detailed guides like those on the Questar Zone (search for “Questar Zone telescope repair” online) or Cloudy Nights forums for step-by-step instructions.
• If the mirror moves but focus still isn’t achieved, or if you suspect worn threads or optical misalignment, contact Questar Corporation (http://www.questarcorporation.com) for service advice. They can assess whether it needs to be sent in for repair.
• Avoid forcing the knob or disassembling beyond the main tube without guidance, as Questar’s precision optics and mechanics are delicate.
If you can provide more details (e.g., the model, year, whether the mirror moves, or what you see through the eyepiece), I can narrow down the issue further. Have you checked the mirror movement or tried switching between finder and telescope modes yet?

[gstrumol]

Get out!!! 

 

That's amazing ...

[ccate]

I wish our sponsor would 'open source' all cn post data since the beginning of time. Some here have the skills to integrate this with a language model. The searching/filtering could be amazing.

[Steve C.]

Grok does seem to be one of the more capable AI's out there. I've been having fun making images.

[Optics Patent]

Clearly, Grok has learned from this site. I am flattered it mentioned my own YouTube channel.

[norcalryder]

Grok is a souped up search engine that can phrase its results in a human manner. It doesn't "know" anything more than what it found searching the internet.

[Steve C.]

Grok is a souped up search engine that can phrase its results in a human manner. It doesn't "know" anything more than what it found searching the internet.

True, but its utility is in the time you save from doing a number of searches to gain that "human manner" of results.