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C11hd collimation screws?

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#1 Stew57

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Posted 29 April 2012 - 07:19 AM

I was collimating my C11hd and messed up one screw. It will have to be replaced next go around. Anyone know the size or know where they stock replacements? They look like 2.5 x 12 mm to me.

#2 nemo129

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Posted 29 April 2012 - 10:56 AM

Mark, they are definitely metric. Bob's Knobs for the next time? Sorry when I sold my 11" EdgeHD I gave the buyer my old collimation screws. :foreheadslap: I would have just sent them to you if I still had them. Good luck.

#3 TG

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Posted 29 April 2012 - 10:56 AM

Mine were 12mm M3 sized. I replaced the stock ones with stainless steel Allen head ones.

Tanveer

#4 ewave

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Posted 29 April 2012 - 03:15 PM

Mine were 12mm M3 sized. I replaced the stock ones with stainless steel Allen head ones.

Tanveer


yep...now that my warranty is about to expire, I will get some allenhead ss types myself.. thanks ;)

#5 Stew57

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Posted 29 April 2012 - 03:20 PM

Thanks guys, I didn't want to take them out yet as I am collimated for now. The next timw they will have to be replace so I will pick some spares up. thanks again.

#6 korborh

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Posted 29 April 2012 - 10:32 PM

I got myself wing-head M3 stainless steel screws that I will replace my Bob's knobs with when I am out of collimation next.
http://www.mcmaster....steners/=hbozav

Bob's knobs are very hard on fingers especially in the cold.

#7 Stew57

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Posted 30 April 2012 - 08:46 AM

Couldn't stand it so I went and bought some m3x12 button head cap screws. They have a head head and fit inside the fastar cap. I just like the screws hidden behind the cap. I use a live video when collimating, I don't hsve to reach around the scope so I didn't really need or want Bob's knobs, or screws that protrude out keeping the cap from closing.

Thanks again for the replies as I would have gooten 2.5s and wasted a trip.

BTW
Did anyone else notice how tight celestron had the screws. My collimation has beeg great for 2+ years. I only went to adjust it after taking the corrector out to clean. I went to tighten one screw (instead of loosen) and messed the head up. Thew were really tight. Maybe that is why the collimation held so well? the ota has not travelled much as it is used in the backyard so I am sure that is a factor also.

#8 TG

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Posted 30 April 2012 - 02:34 PM

BTW
Did anyone else notice how tight celestron had the screws. My collimation has beeg great for 2+ years. I only went to adjust it after taking the corrector out to clean. I went to tighten one screw (instead of loosen) and messed the head up. Thew were really tight. Maybe that is why the collimation held so well? the ota has not travelled much as it is used in the backyard so I am sure that is a factor also.


I don't remember how tight the original screws were but my approach is to finish fine collimation by tightening all screws. This maintains collimation far better (I have never recollimated after I replaced the screws) than if the screws are finger tight and is the reason I went for Allen-heads as the torque afforded by the hex-keys is much more than what your fingers can manage with, say, Bob's Knobs. It also got rid of the "sudden-give" problem I had with BKs.

One great thing about the HDs is that because the optics are coma-free, you never have to keep recentering the star while collimating.

Tanveer.

#9 dobsoscope

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Posted 03 December 2012 - 06:21 AM

Do you know which sizes are the ones of the C14 EdgeHD please?






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