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C14 Secondary spins easily

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#1 Ron Luxemburg

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Posted 22 January 2013 - 01:59 PM

Last night while doing a tiny collimation tweak the secondary housing spun so easily I had to hold it firmly in order to do an adjustment. Mine is an older mid 80's model, it was a black tube originally but now is white. For now I am going to just leave it alone and be very careful but would be interested in hearing from others who have had this issue and how they dealt with it or were able to fix it. Seems like this happens more in colder weather, and compared to others my nights are only in the 40's out here in SoCal. Any input or advice would be much appreciated.

#2 telfish

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Posted 22 January 2013 - 03:25 PM

The Secondary is designed to line up with the serial number pointing to the 3 o'clock position.

In order to tighten it you will need to take the corrector off, then tighten the secondary line it up and then replace the corrector making sure it too is lined up with the mark at the 3 o'clock position.

You might wish to cut a sorbathne washer to stop this happening in the future.

If you do take it apart take particular note of the position and number of the cork spacers that center the corrector and replace them in the same position.

#3 Ron Luxemburg

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Posted 23 January 2013 - 01:47 AM

Thanks for the reply, yes I am aware of the alignment issues. I guess I'm hoping to hear from someone who had this same issue and who was able to solve it and willing to describe what they did. I've been told that the inside baffle tube is actually not only threaded on but glued as well. Starizona talks about how to break those glue bonds on their site for people interested in changing their stock Celestron into a hyperstar ready version. As long as it only spins and it doesn't begin to wobble I think I'll be ok for awhile, but it would be nice to get it firmly locked down in the near future.

#4 telfish

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Posted 23 January 2013 - 08:24 AM

When I changed my C11 to hyperstar the old secondary came off easily. I just squeezed the inside part and the glue popped.

Then it unscrewed. You might consider ordering a C14 conversion from Stararizona even if you would not be using a hyperstar.

The reasons are, the whole assembly is well machined metal rather than the cheap plastic of the original. the assembly comes with a sorbathane washer which totally solves the rotation issue, and the collimation seems to hold better.

#5 Starhawk

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Posted 23 January 2013 - 08:57 AM

I second this approach- it has worked quite well for me.

-Rich

#6 rmollise

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Posted 23 January 2013 - 08:59 AM

Some are harder, some are easier, some secondaries are just glued, some are threaded and glued. I find the glue is often not that easy to break, but gentle pressure with strap wrenches is often enough to do the job.

#7 Ron Luxemburg

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Posted 23 January 2013 - 01:06 PM

Thanks Guys, I really appreciate the input and feedback. Mine is the original C14 with the center bolt as well. This happened to a close friend of mine who knew a lot of the crew at Celestron directly. He took his to them hoping they could fix it, well they ended up breaking his corrector plate in the process of trying to get the secondary housing off! After that happened Celestron installed a brand new set of optics with XLT into his older tube. I think he was with out his C14 for about 2 months and mind you we both live in SoCal, and can drive directly to Celestron, there were no shipping delays. Anyways, I don't want this to happen to me so I am very reluctant to put much force into getting my secondary off and replacing it with the Starizona option although I did and am thinking about it. What I am noticing is that my collimation is not holding and I need to tweak it more often. I've heard Meade secondaries are much easier to deal with and are not glued.

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#8 Ron Luxemburg

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Posted 23 January 2013 - 01:14 PM

Here's an image of the working back end of the scope with my custom hand made handle bracket with counterweights which off set the weight of the dew shield. Might call Starizona and talk to them about their secondary housing as I plan to keep this scope and it would be a worthwhile upgrade.

#9 Ron Luxemburg

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Posted 23 January 2013 - 01:17 PM

Here's the image I mentioned in the post.

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#10 telfish

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Posted 23 January 2013 - 01:37 PM

Nicely done. If the C14 secondary is the same size as the C11 than you can have my old secondary assembly just in case yours breaks when you try and remove it.

I am guessing yours is a bigger size but you are welcome to it if it fits.


Terry

#11 Ron Luxemburg

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Posted 23 January 2013 - 06:06 PM

Thanks Terry for the offer, pretty sure the C14 secondary is larger in diameter then the C11.






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