The four little grub screws are potentially lateral alignment adjustment, used at the factory to align the centers of corrector and secondary with the primary. My vintage Celestrons use cork shims. Lateral and rotational matching of the corrector is performed to get the wave error as low as possible and meet specifications.
I just popped the secondary out and used kimtech wipes while wearing thin vinyl gloves to remove the haze that had collected inside the corrector plate. Other than the minimal amount of dust that snuck in, it's as good as new.
@@deepskyutah5257 I'm just realizing that mine's the 14 inch version and that with the thinner scopes, it might not be as easy to fit one's hand through the hole at the center of the corrector plate, so ymmv
That is not fungus but gassing from the paint or the epoxy that Celestron uses. They are aware of it and would have cleaned the telescope for free. Though shipping cost is borne by the customer. I will do it a little differently. I will not loosen all 4 grub screw. Just loosen the top two that way your corrector and secondary alignment will not change. Also very important is the Indexing of the corrector. It should not rotate in the housing at all. There is a notch on the secondary mirror housing at 3 o'clock if I remember right.(That was the norm on the non-edge SCT's). So its important to mark the corrector orientation precisely. Also do not remove any of the spacers or cork between the corrector and the metal ring holding it in place. Finally do a star test. Even after collimation if you see any spikes and not a perfect round star with diffractions rings, loosen the screws on the outer ring. But just barely. The idea of the outer ring is just to grab the corrector firmly and not pinch it. I had the gassing on my c14 edge. I just removed the secondary and I could reach the inside of the corrector lens through the hole in the centre. I have cleaned the C8 and C11 quite successfully.
Thanks for the comment and information, Jay. Hopefully I won't ever have to clean it again, but all works perfectly after re-assembling. It's a very fine telescope!
If you go to the HuTech video on sct collimation they explain that those 4 screws are used to adjust the corrector plate so it is in the center of the optical axis of the telescope as a whole. It's a very interesting video to watch but I don't have the $450+ to plunk down on a tool I would rarely use. If you're in an astronomy club maybe the members could get one for everyone to use when they need to. Unfortunately I don't think my NX11 has those 4 screws in it and that C used shims or something to center the plate. Will be pulling it very soon as I just got the gasket today for the secondary mount to stop the secondary holder from rotating when I take it out and put on my HyperStar so I will find out how they centered the plate.
Ahhh, thanks for the pointer. That makes sense. Luckily I haven't had any issues with mine since I cleaned it. I checked collimation and it was close enough for me. I think I can say that the Edge is my sharpest telescope and produces much better stars on the edges than my refractors.
need to be really careful and tender with those "grub screws". Those screws play a key role in centering your secondary mirror in the absolute center of the optical train. I recommend only loosening a single grub screw and make note of how much you turn it. Just loosening one should provide enough gap all the way around to remove the corrector plate. If you dont get that secondary mirror back in its proper position, you will have a heck of a time getting it there. Might have to send the OTA off.
Just wondering just undoing the whole front assembly from tube is the better option just take off the dove tail. Then you just mark tube and from assembly rather than corrector plate
Do you have any problems to turn that plastic cover of collimation screws with fastar stick? my turns about a milimiter and stucks. Any suggestions how I can get to this collimation screws?
Distilled water and light soapy water if needs be is all I would use, some products have alcohol in them and that can remove or damage the special coatings. Glasses cleaners are a big No because some of them contain alcohol or other solvents that can basically destroy your optics.
Wow, hope that works when you try it again? Ive seem quite a few vids on Doing this. None like yours.. scarey to watch.. lol Got a ton of dog hair in mine.. love the bubble wrap! Great idea!!
Haha, I know what you mean. Everything turned out A-OK! It's still the sharpest telescope I own edge to edge. I have to keep everything in the garage...it's the only place not covered in dog and cat hair, lol.
I should add that I did check the collimation on an out of focus star. I think I made some minor adjustments, but those could have been needed before removing the corrector.
I had the corrector out on my 925 Edge yesterday but those 4 adjustment screws you mentioned seem to be locktight in the outer tube. I can't even tell if they are hex screws as Celestron must have applied something to them at manufacturer to stop them moving. Do you recall if they are hex screws?
Hey Simon, I do believe the are hex screws. Is there some kind of of coating on them preventing access? Mine were clearly visible, but maybe the first owner had worked on it previously.
@@deepskyutah5257 Just reading the White Paper for the Edge - they apply Locktite to the adjustment screws to permanently hold them in place. They seem to have added Locktite into the head of the hex screw too as I had issues trying to figure out what kind of screw it was they used...
@@SimonT65 interesting. Someone must have done some work on mine before I purchased it because those screws came out pretty easily for me. Maybe I'll use a little of the blue stuff if I open it up again.
@@deepskyutah5257 Just an update on this as I worked on my 925 yesterday. Celestron use Locktite to fix those adjustment screws in place. I heated an Allen Key using a heat gun, the heated Allen Key melted the Locktite so I could easily adjust the screws.
Isopropanol to clean first... Then Distilled water to rinse.... Then Dry to remove residue... Cotton balls in small circular motions working from the inside out both Cleaning and drying just like a camera lens...
![จบจนได้ ! | Black Myth: Wukong #007 [ตอนจบ?]](http://i.ytimg.com/vi/DSqvWndF0sw/mqdefault.jpg)
The four little grub screws are potentially lateral alignment adjustment, used at the factory to align the centers of corrector and secondary with the primary. My vintage Celestrons use cork shims. Lateral and rotational matching of the corrector is performed to get the wave error as low as possible and meet specifications.
I just popped the secondary out and used kimtech wipes while wearing thin vinyl gloves to remove the haze that had collected inside the corrector plate. Other than the minimal amount of dust that snuck in, it's as good as new.
Very nice! I'll look into the Kimtech wipes next time I need to do this type of cleaning.
@@deepskyutah5257 I'm just realizing that mine's the 14 inch version and that with the thinner scopes, it might not be as easy to fit one's hand through the hole at the center of the corrector plate, so ymmv
Well done. My first attempt at this last week caused a crack in my C9.25 XLT corrector plate. Hopefully help is at hand.
How did things turn out for you?
@@Michael.Chapman Still unrepaired.
That is not fungus but gassing from the paint or the epoxy that Celestron uses. They are aware of it and would have cleaned the telescope for free. Though shipping cost is borne by the customer.
I will do it a little differently. I will not loosen all 4 grub screw. Just loosen the top two that way your corrector and secondary alignment will not change. Also very important is the Indexing of the corrector. It should not rotate in the housing at all. There is a notch on the secondary mirror housing at 3 o'clock if I remember right.(That was the norm on the non-edge SCT's). So its important to mark the corrector orientation precisely. Also do not remove any of the spacers or cork between the corrector and the metal ring holding it in place. Finally do a star test. Even after collimation if you see any spikes and not a perfect round star with diffractions rings, loosen the screws on the outer ring. But just barely. The idea of the outer ring is just to grab the corrector firmly and not pinch it.
I had the gassing on my c14 edge. I just removed the secondary and I could reach the inside of the corrector lens through the hole in the centre. I have cleaned the C8 and C11 quite successfully.
Thanks for the comment and information, Jay. Hopefully I won't ever have to clean it again, but all works perfectly after re-assembling. It's a very fine telescope!
If you go to the HuTech video on sct collimation they explain that those 4 screws are used to adjust the corrector plate so it is in the center of the optical axis of the telescope as a whole. It's a very interesting video to watch but I don't have the $450+ to plunk down on a tool I would rarely use. If you're in an astronomy club maybe the members could get one for everyone to use when they need to. Unfortunately I don't think my NX11 has those 4 screws in it and that C used shims or something to center the plate. Will be pulling it very soon as I just got the gasket today for the secondary mount to stop the secondary holder from rotating when I take it out and put on my HyperStar so I will find out how they centered the plate.
Ahhh, thanks for the pointer. That makes sense. Luckily I haven't had any issues with mine since I cleaned it. I checked collimation and it was close enough for me. I think I can say that the Edge is my sharpest telescope and produces much better stars on the edges than my refractors.
need to be really careful and tender with those "grub screws". Those screws play a key role in centering your secondary mirror in the absolute center of the optical train. I recommend only loosening a single grub screw and make note of how much you turn it. Just loosening one should provide enough gap all the way around to remove the corrector plate. If you dont get that secondary mirror back in its proper position, you will have a heck of a time getting it there. Might have to send the OTA off.
Just wondering just undoing the whole front assembly from tube is the better option just take off the dove tail. Then you just mark tube and from assembly rather than corrector plate
Do you have any problems to turn that plastic cover of collimation screws with fastar stick? my turns about a milimiter and stucks. Any suggestions how I can get to this collimation screws?
What hand motion did use to actually clean the glass with the wipes
Hi,
Can you tell us which tool( Allen,..) did you use to take the Schmidt plate out ?
Thanks
Distilled water and light soapy water if needs be is all I would use, some products have alcohol in them and that can remove or damage the special coatings. Glasses cleaners are a big No because some of them contain alcohol or other solvents that can basically destroy your optics.
Wow, hope that works when you try it again? Ive seem quite a few vids on Doing this. None like yours.. scarey to watch.. lol
Got a ton of dog hair in mine.. love the bubble wrap! Great idea!!
Haha, I know what you mean. Everything turned out A-OK! It's still the sharpest telescope I own edge to edge. I have to keep everything in the garage...it's the only place not covered in dog and cat hair, lol.
I should add that I did check the collimation on an out of focus star. I think I made some minor adjustments, but those could have been needed before removing the corrector.
Good 9:49am july22/23
Would you know the size of the four screws holding in the corrector plate?
Sorry, I don't know what size they are.
I had the corrector out on my 925 Edge yesterday but those 4 adjustment screws you mentioned seem to be locktight in the outer tube. I can't even tell if they are hex screws as Celestron must have applied something to them at manufacturer to stop them moving. Do you recall if they are hex screws?
Hey Simon, I do believe the are hex screws. Is there some kind of of coating on them preventing access? Mine were clearly visible, but maybe the first owner had worked on it previously.
@@deepskyutah5257 Just reading the White Paper for the Edge - they apply Locktite to the adjustment screws to permanently hold them in place. They seem to have added Locktite into the head of the hex screw too as I had issues trying to figure out what kind of screw it was they used...
@@SimonT65 interesting. Someone must have done some work on mine before I purchased it because those screws came out pretty easily for me. Maybe I'll use a little of the blue stuff if I open it up again.
@@deepskyutah5257 Just an update on this as I worked on my 925 yesterday. Celestron use Locktite to fix those adjustment screws in place. I heated an Allen Key using a heat gun, the heated Allen Key melted the Locktite so I could easily adjust the screws.
@@SimonT65 that's a great idea with the heated Allen key. Thanks for passing on your experience!
Isopropanol to clean first... Then Distilled water to rinse.... Then Dry to remove residue... Cotton balls in small circular motions working from the inside out both Cleaning and drying just like a camera lens...
Do NOT wipe the corrector plate with anything... Use a Polymer Solution from Photonic Cleaning Technologies.
You don't need any fancy cleaning solution. Go shill your crap elsewhere.
Distilled water, Ivory Liquid.
All you need.