Moonlite - Fine Adjustment Knob

[johnb]

Hope someone can help with my Moonlite Issue, the fine adjustment knob has come away from the main unit but 
I simply cant see how to get it back in

It wont simply push back in as it does not go in all the way and i notice the spindle has a small groove and again does that go in the knob or the main unit - hopefully the pics explain

I looked on line but could not seem to find much

Help appreciated

Regards

John B

 

[Astrobits]

Here's a diagram that I obtained from a Chinese observatory when I was making my own units. The shaft goes through the three ball bearings and the balls ride in that groove. You will probably have to dismantle the whole focusser unit to get the knob back together again including removing the shaft from the fine focus knob. 

Nigel

[Peter Drew]

I'm afraid Nigel is correct. You have to dismantle the unit enough to release the three balls. You can then slide the shaft back in, replace the three balls which will now line up in the shaft groove, this drives the slow motion at the same time as retaining the balls and operating shaft.   

[Astrobits]

Here's a tutorial on a GSO focuser strip-down and re-assembly to give you some idea as what to expect.

http://polluxchung.com/gso_crayford_fix/

Nigel

[johnb]

6 hours ago, Astrobits said:

Here's a tutorial on a GSO focuser strip-down and re-assembly to give you some idea as what to expect.

http://polluxchung.com/gso_crayford_fix/

Nigel

thanks

[VuurEnVlam]

Hello, 

I know this is an old post, but I'm raising it back because I found myself in the same situation while trying to disassemble the fine adjustment knob in order to install a focuser motor.

I'd already started to disassemble the focuser to reach and release the three balls shown in the diagram in the previous replies when, during the process, I casually figured out that for the Moonlite's crayfords (mine is a CHL 2.5, the one for edge SCTs, but this could be probably the same for other Moonlite models) the thing it's easier to solve:

After you remain with the fine-focusing shaft in your hand.. You have to remove the coarse knobs from both sides; then by pushing (and hold, there's a spring) the shaft of the coarse-adjustment side, the whole 'balls mechanism' will pop up giving enough room between the balls to insert back the fine-focusing shaft; then releasing the pressure on the coarse-adjustment shaft the mechanism is pulled back again by the spring, engaging the fine-adjusment shaft . 
I attached a video that shows how the mechanism pops up pressing the coarse knob shaft, when is out the fine-adjustment shaft can be insered back.

That's it. I wanted to share this here because this is the first and only link/post/thread I found searching online for help about this specific issue with this specific focuser brand so. Hoping the above is understandable and could help someone in the same situation that walks past here as I did. 

Stefano

Edited November 21, 2020 by VuurEnVlam

[MultumInParvo]

On 21/11/2020 at 16:14, VuurEnVlam said:

Hello, 

I know this is an old post, but I'm raising it back because I found myself in the same situation while trying to disassemble the fine adjustment knob in order to install a focuser motor.

I'd already started to disassemble the focuser to reach and release the three balls shown in the diagram in the previous replies when, during the process, I casually figured out that for the Moonlite's crayfords (mine is a CHL 2.5, the one for edge SCTs, but this could be probably the same for other Moonlite models) the thing it's easier to solve:

After you remain with the fine-focusing shaft in your hand.. You have to remove the coarse knobs from both sides; then by pushing (and hold, there's a spring) the shaft of the coarse-adjustment side, the whole 'balls mechanism' will pop up giving enough room between the balls to insert back the fine-focusing shaft; then releasing the pressure on the coarse-adjustment shaft the mechanism is pulled back again by the spring, engaging the fine-adjusment shaft . 
I attached a video that shows how the mechanism pops up pressing the coarse knob shaft, when is out the fine-adjustment shaft can be insered back.

 

That's it. I wanted to share this here because this is the first and only link/post/thread I found searching online for help about this specific issue with this specific focuser brand so. Hoping the above is understandable and could help someone in the same situation that walks past here as I did. 

Stefano

Hi Stefano,

I have taken the coarse focus knob off from the other side but I can't seem to get the same movement as you have here, is there something else I need to remove or loosen?

Thanks in advance,

Ian

[MultumInParvo]

Actually, I just needed to be a little braver and push a tiny bit harder on the spindle.

 

Thanks for this Stefano, literally the only place on the internet with this information.

Ian