Selected LX200 & Tripod Specifications

       

Subject: Rear Cell Thread Specs --part 1 of 3    

From: Doc G, Date: Oct 2002

----- Original Message -----
From: Anthony Kroes:
> Does anyone know the specifications for the threads on the rear cell of
> the 'classic' 12" LX200? I would like to try my hand at making an adapter
> (like the Eyeopener) for the rear of my scope. It would be nice to use
> the full 2" light path instead of choking down to the SCT thread adapter

I do not have a specification. I have made such an adapter and found the following dimensions to work well. Bore to 80.8 mm and cut with a 60 degree boring bar. 1.75 mm thread to a depth of 1.2 mm. You may have to adjust very slightly to get a nice snug fit. I usually cut a bit less and then open up to fit. I do this all in metric since I have a metric lathe.

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Subject: Rear Cell Thread Specs --part 2

From: Roger Hamlett <ttelmahntlworld.com>

Have just gone and rechecked with a thread gauge, and it measures out as 16TPI, or 1.6mm (over the typical 0.5" if thread, you can't see the error between these two). You are cutting oversize significantly (3.37 to the outside of your tool). You are getting away with it, because of the very short threaded length on most scopes... I have checked on a Celestron scope, a Meade scope, and on both Meade, and Losmandy fittings.

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Subject: Rear Cell Thread Specs --part 3 of 3    

From: Doc G

I believe the specifications for Meade threads is probably English. Thus the 3.25" and 16 TPI is a correct "specification." I use all metric since I am an electrical engineer and have metric machines. Most of the adapters I have purchased are very loose. I make mine very tight. But there are only 3 threads that engage so the thread pitch is not very critical. I cut at 1.75 because it is easy for me with the metric lathe. I may have had a gear ratio that gave me 1.65 for one of the setups. But with only three threads engaging I am close enough. I have checked another adapter and it looks like 81mm bore and 1.3 mm thread depth. That is very close. Everytime I need to do English threads, I have to fiddle with the gears to get close enough.

I cut the threads with a right angle boring bar with a 60 degree tip. The trick I use to do this without endangering a jamb, is to cut the thread from the inside surface out. You have to run the head backwards and use a left handed tool.

Subject: Dec Bearing Shaft Size     

From: Mike Dodd <mikemdodd.com> Date: Feb 2003

I own a later model 10" LX200 that has metal bearings, so I don't need to perform the modification. However, the information about disassembly and reassembly/alignment are helpful because I'm going through the procedure to align the forks and OTA.

It turns out that the 1" steel shaft that's mentioned for leveling the forks (also mentioned in the appendix citing Jim Mettler) is not 1" any more. Mine measures 0.984" - which is exactly 25mm. It seems that Meade went overseas for the steel bearings.

In any case, the 1" shaft is needed for the old Nylon bearings, but if the scope has factory-installed steel bearings, buy a 25mm shaft.

Subject: 12" Baffle Tube Dimensions  

From: Alan Voetsch <critter12952yahoo.com> Date: Feb 2003

12" LX200:

• Main baffle tube OD is 2 1/2"
• Main baffle tube ID is 2 3/8"
• Secondary baffle length from inner surface of the corrector is 1 -21/32"
• Secondary baffle OD is a shade under 4" say 3 -63/64"

Subject: When LX200 Made Switch to Metal Bearings --part 1 of 2     

From: Rod Cook <cookrodgurulink.com> Date: Mar 2003

Dave, I agree with you that a definitive cut-off based on serial numbers was not determined. Your message persuaded me to try again to remove the setting circle cover on the east dec arm. This time I got it to turn, perhaps the cool weather helped this time. I am pleased to report I found steel bearings. This scope was shipped from the factory, and I received it around 10 October 2000. Serial number 127540.

The messages Jason sent earlier were the data I was thinking of. To summarize the data he provided and adding mine for 12" LX200 classics:
  S/N121905, Nylon, received 3 March 2000 (ordered 27 Dec 1999)
  S/N124523, Nylon, bought 29 January 2000
  S/N125753, Nylon, bought May, 2000
  S/N125773, Steel, received May, 2000
  S/N127540, Steel, received 10 October 2000 (ordered 29 June 2000)
  S/N129819, Steel, received Fall 2001

This information, although limited, does support our contention the change took place in the spring of 2000.

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Subject: When LX200 Made Switch to Metal Bearings --part 2 of 2    

From: Dave Schanz <dave23schvalleytranscription.com>

Now we're starting to narrow the change over to an actual serial number! Based on the info in the database, it seems that Mother Meade simply slaps a serial number on a scope as soon as it is ready to ship (or some other final QA point)? The data seems to strongly suggest that serial numbers for the 10 and 12" models start with a 1 ( the 8" start with an 8, the 7" MAKs with a 7 and the 16" start with a 16). The 10" and 12" models seem to have serial numbers suggesting that whichever is ready to ship next gets the next serial number in the sequence.

Given that assumption, the scope noted below - S/N 125773 was received in May of 2000 with steel bearings. My 10", S/N 125753 was received from OPT stock in late May, 2000 with plastic bearings. So, one could assume that the plastic-to-steel switch occurred at some point between S/N 125753 and 125773.

I would think it is safe to say that if a person has a 10" or 12" classic with a serial number prior to 125753 it has plastic bearings. Serial numbers above 125773 have the metal bearings. If someone has a serial number between the two, then we want to hear from you!