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nspace01 |
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Wednesday, September 30 2009 @ 10:23 pm EDT (Read 5257 times) |
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Sage
Status: online
Registered: 03/27/05 Posts: 390
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Well, my (Almost) new Meade LXD55 SN-10 Schmidt-Newtonian OTA came via UPS yesterday.
Generally, it was in pretty good shape for a 6 year old, used $300.00 scope.
The corrector plate/secondary mirror assembly was removed and packaged separately for shipment by the previous owner. (Nice of him).
The Corrector plate, and the primary and secondary mirrors were a little dirty, as can be expected, for a 6 year old scope. Following expert advice from several astro websites and forums, I carefully cleaned the corrector plate, secondary and primary mirrors. I used a whole big bag of cotton balls and about half a pint of 90% isopropyl alcohol in the process. The wife thought I was crazy, being so thorough and careful...........but as anyone that has been in this hobby for a while knows, you CAN'T be too careful when you touch a mirror surface or a multicoated optical surface. Your best bet is to leave-em be...........As it turned out, niether of the mirrors or the corrector plate had as much as scratch or a smuge on them when done. Look like new!
The following are Modifications I am making to the OTA, as improvements to the original, since I have it apart anyway:
Mod #1
The Meade (plastic) stock focuser was replaced a couple of years ago by the previous owner, with a JMI MotoFocus Electronic Focuser with hand controller. It works very well and is very robust, but, sadly, is for 1 1/4" eyepieces only. I have two new 2" University Optics eyepieces, so I really can't use this focuser. I removed it from the OTA and have it listed in the "For Sale Forum" for anyone that is interested. (If it doesn't sell in a couple of weeks I will donate it to AOAS to use on one of our club scopes.)
I just happen to have a new Moonlite CR2 focuser just laying around, waiting on a 14" mirror, so I ordered a Moonlite mounting kit for the SN10.
With mounting kit, the CR2 will mount using the same factory holes that the original factory focuser used and will place the focus at the same height.
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nSpace01
nSpace01
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nspace01 |
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Wednesday, September 30 2009 @ 11:35 pm EDT |
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Sage
Status: online
Registered: 03/27/05 Posts: 390
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Mod #2
The previous owner had removed the original dovetail bar to use an a new OTA with the LXD55 mount.
I removed the 13" Dovetail bar from my 10" SCT OTA and have attached it to the tube rings that came on the SN10. The "New" rings are much lighter than the old ones, being iodized aluminum instead of painted steel.
Since the tube rings on the SCT are the same diameter, I will be able to switch them back and forth between scopes as needed.
One of the minor problems with Schmidt-Newtonians and Newtonians as well, are the awkward positions that the eyepiece can be in on a equatorial mount. One approach to alleviate this problem is through the use of "Rotating Tube Rings". These can be very expensive.
One inexpensive alternative are "Wilcox Rings". These were invented by an amateur astronomer and work almost as good as the expensive ones.
http://www.andysshotglass.com/wilcox_rotating_rings.html
Mine cost less than $20.00 to make. The only variation I made was that I used 5/8" Rubber Tubing (heater hose) and mounted them both on the underside of both scope tube rings, as described on annother Astro Forum.
After installation, you can lossen the regular tube rings and rotate the OTA without it sliding downward, upsetting the balance on the mount, or worse, having your OTA slide off the mount and hit the ground.
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nSpace01
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nspace01 |
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Thursday, October 01 2009 @ 12:08 am EDT |
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Sage
Status: online
Registered: 03/27/05 Posts: 390
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nSpace01
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dgrosvold |
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Friday, October 02 2009 @ 11:12 am EDT |
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Admin
Status: offline
Registered: 06/18/03 Posts: 449
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Leonard - this scope sounds pretty cool! I'll be very interested in seeing it at our earliest opportunity. Are you going to bring it with you to the RRAC Burgerburn? That would be great!
Dave - Morrow, AR
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LME |
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Sunday, October 04 2009 @ 07:09 pm EDT |
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Sage
Status: offline
Registered: 03/06/08 Posts: 140
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Wow Leonard, you've been busy! The Wilcox Rings you mentioned is money well spent! I made my own soon after my newt arrived, they work great.
Clear Skies-Larry
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nspace01 |
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Wednesday, October 07 2009 @ 01:09 am EDT |
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Sage
Status: online
Registered: 03/27/05 Posts: 390
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I've got the scope ready for "first light".
I got a 12 volt PC Case Fan and a filter cover and mounted it with 1/8" nylon wire ties in the center of the back of the primary. The fan is about 1/4" from the mirror.
I wired the fan to a female connector so I can plug it in to my Power Tank that I use to power my mount.
I received via UPS the adaptor kit I ordered from Moonlite and I mounted my Moonlite CR2 on the SN-10 OTA..........Gawd, it is purty and smooth as butter to focus.
I used a laser collumator and seem to have a good collumation. I won't really know untill I do a star test. From what I have read, any time you have a corrector plate, it can be a little tricky.
nSpace01
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bobmoody |
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Wednesday, October 07 2009 @ 05:52 pm EDT |
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Sage
Status: online
Registered: 06/19/03 Posts: 461
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Hi, Leonard.
You have a very good photographic telescope there. Using your DSLR, it should give you a great picture when you get everything set just the way you want it.
It is a little late to suggest this, but usually when an optical component is removed such as what you described, they should have marked the outside edge of the glass itself with either a spot or a pencil mark or some way to assure that the plate goes back on EXACTLY as it came off....i.e. with the correct side out, and aligned usually with the focuser. Those things are usually aligned using sophisticated machines to give the most precise view. This may be critical, and I hope it works for you right away.
However, if you do decide you need to try repositioning the corrector to get rid of any lingering coma in the future, try checking that outside edge for any trace of a mark. If the previous owner did HIS homework properly, maybe you'll find what I'm talking about. Hopefully you didn't use anything to clean that very outside-edge and the spot (if there was any) may still be there.
Hope it works and I look forward to seeing it later this month, if we EVER get any skies again, that is!
Bob
Bob Moody
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nspace01 |
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Wednesday, October 07 2009 @ 06:06 pm EDT |
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Sage
Status: online
Registered: 03/27/05 Posts: 390
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As far as I know, the corrector plate and mirror mount went back, alined as they were "factory fresh".
If I can just get an evenning with a clear sky.....................Thought we might have one tonight...........but clouded over (as usual).
nSpace01
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nspace01 |
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Wednesday, October 07 2009 @ 07:09 pm EDT |
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Sage
Status: online
Registered: 03/27/05 Posts: 390
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I ordered a used 50" tall,18" wide, and 14" deep bag for the OTA.
It even has a zippered compartment for "Golf Shoes & Balls", whatever they are........
nSpace01
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LME |
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Wednesday, October 07 2009 @ 10:19 pm EDT |
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Sage
Status: offline
Registered: 03/06/08 Posts: 140
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Hey Leonard- Does the zippered bag come with air conditioning or maybe curb feelers?
Clear Skies-Larry
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nspace01 |
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Wednesday, October 07 2009 @ 11:05 pm EDT |
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Sage
Status: online
Registered: 03/27/05 Posts: 390
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Just a ventilation fan that runs on AAA batteries and red LEDs on the top corners.
nSpace01
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nspace01 |
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Tuesday, October 13 2009 @ 02:59 pm EDT |
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Sage
Status: online
Registered: 03/27/05 Posts: 390
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nSpace01
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