LX200 Related Miscellaneous Items

MAPUG-Astronomy Topical Archive     AstroDesigns    MAPUG-Astronomy.net

 

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Subject: Replacement for Broken Power Connector

From: John Mahony <jmmahonya_thotmail.com>

Dr. G Neal Mauldin wrote:
> Unfortunately, my Radio Shack didn't have this. The reason I asked the
> question originally is that I took the connector in yesterday, and they
> sold me the one that they were "sure" would fit (a type "M" connector).

Yes, the ID is 2.5mm, which is type N in Radio Shack's system. Center is positive.

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Subject: Classic LX200 Firmware Version and the Keypad Version

From: Gene Kahn <gdkahna_tpacbell.net>

There are 2 different version numbers.

The 3.21 label on the back of the hand controller or keypad refers to the firmware version on the microcontroller in the hand controller.

The 3.34 or whatever that comes up on the hand controller or keypad display during boot-up refers to the firmware version of the ROMs on the motherboard in the base of the scope.

rule

Subject: Accurate Finder Registration  Top

From: Rob Roy <rroya_texeculink.com>

Many have complained that they can't get the finder to register in the same spot from one session to the next. Here's an easy way to fix that.

Take out the two holding screws and put the finder in its mount, pushing it back and down to seat it properly. You can now mark where the screws will touch the mount with a just-fitting sharp drill hand-twisted in each hole. Remove the finder scope and drill a small depression for each screw to sit in, when tightened. Each time you use the finder, the screws should sit in the same depressions and place the finder in the exact same spot.

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Subject: Powering the Telrad on the LX200  Top

From: Tony Kroes <tkroesa_tdct.com>

I simply wired my Telrad battery leads through a hole in the back of the unit to the reticule port on the face of my 8" LX200 with a standard 1/8" mono headphone plug. I tested to output of the reticule port ahead of time and it was about 5V. I didn't figure the 2V difference would adversely affect the Telrad target LED. Seems to work great with no special resistors or anything. I can now turn the unit on and adjust brightness with the Telrad switch, or leave the Telrad unit on all the time and use the LX200 hand unit to adjust it. Ran it for 2 nights at Astrofest a couple weekends ago and it worked like a charm! Seemed to be about the same brightness range also.

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Subject: Hardwiring Telerad to LX200    Top

From: Michael Clary

A couple of days ago, there was an exchange of list mail regarding use of the LX200 reticle port to power and control a Telerad. I completed the modification today and it's great! No more worry about the "AA" batteries dying plus I now have a pulsing bullseye. Just in case anyone else is considering this 10 minute mod, a few details are provided.

I bought a 6' Radio Shack (Cat no. 42-2434) shielded audio cable with a 1/8" mini plug on one end and tinned ends on the other. I picked up some grommets at Fry's Electronics...I got 1/8" ID for 1/4" hole and it was really tight...I'd recommend the next size up unless you are trying to make a watertight hole. I drilled my hole in the end of the Telerad away from the viewing end to avoid threading the cable through the electronics. Center post of the audio cable was soldered to the red lead (after cutting off battery case and tinning the red/black leads) and the ground was soldered to the black lead. Packed everything back in the Telerad housing and fired up the LX200. Turned the Telerad switch to full on and used the LX200 hand paddle for control. Pressing and holding the Ret button, I can push the Guide button for 100% bullseye and the Map button for a pulsing bullseye...neat!

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Subject: 1x Finder Recommendation --part 1 of 2   Top

From: Tom Wideman <toma_twideman.org>

I've got two Telrads (now with flasher circuits and dew shields with flip-up mirrors for angle viewing, total Telrad geekdom), as well as two Daisy BB-gun sights I've modified. The Telrad is nice but bulky, the Daisy thingy is cheap.

Having said that, I have to say, loud and clear, that the Stellarvue red dot finder is the best bang for the buck out there, in my opinion. I am very impressed with it (I had one on a Stellarvue refractor; I purchased it after the refractor, and almost didn't sell it with the refractor, I liked it so much). If I were going to buy one now, it would be the Stellarvue. A very nice unit. It is very compact, but the viewing window is larger than others of similar size and shows up well. The dimmer knob is large and easy to use. Overall, an impressive unit.

The expensive Televue (I can never remember which Televue is which) is kinda cool -- it's impressively made as all Televue stuf is, but it costs more than some telescopes and the dot is kind of big for some folks. If I had unlimited funds, I would look at it, but I still like the Stellarvue.

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Subject: 1x Finder Recommendation --part 2 of 2   Top

From: Bill Arnett <billa_tnineplanets.org>

Another good alternative is the QuickFinder:

   <http://www.vtc.net/webusers/crazyed/catalog.html#FINDERS>

It's smaller and lighter and a little cheaper than a Telrad but provides more than a simple dot.

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Subject: LX200 Touch-Up Paint   Top

From: Bob Proskey

I have found an excellent match to the Meade blue at K-Mart. It is a spray, but you can spray some onto something and use either a brush or toothpick to do the job,. The brand is by Rustoleum and called Painter's Touch. The color is Navy Blue gloss number 1922. Costs about $4.00 and is so close to Meade's color you can barely tell them apart.

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Subject: Washer for 2" Diagonal Rotation--part 1 of 2   Top

From: D. Garris

I took a piece of polyethylene and did just that! I used scissors to cut out the washers and then I used my dremel tool to carefully trim out the insides of each washer! It was time consuming but the end result looked like a nice factory plastic washer made for the LX200 diagonal. I placed one washer between the SCT and the threaded locking collar on the diagonal and then other washer after very carefully trimming it, I placed behind the threaded locking collar. Of course to do this I had to unscrew the barrel from the diagonal. It WORKS!!! I installed the diagonal with the carefully home-made polyethylene washers on my 12" LX200 in it's soft case last night to see how it felt and it felt rather smooth and very snug. Quite easy to turn yet felt it had plenty of "hold" power. It will be interesting to see how my modification works out in the field! Now if I can find out if I can get another "threaded collar barrel" (the metal tube that must be unscrewed to allow installation of the inside washer) for my diagonal I unknowingly put a few nice scratches on it while trying to unscrew it from the diagonal. Anyone know where I can get a part for the diagonal or is it best to get a used or salvaged one and swap the small threaded collar barrel out?

Also since I realize others may be interested in this post, The plastic I used was at a hardware store. I found one of those plastic little storage bins with the open and close top lid for about $1.99. The kind of thing you put hardware or screws or small parts in. It was the same material in description as a plastic coffee can lid but just a bit thicker and heavier almost clear in color with a milky white appearance is as best I can describe it. I used the lid of the storage box I purchased. It is Polyethylene, very slick to the feel, flexible, soft but hard to cut with a razor blade. Used scissors to cut outside diameter and used dremel tool to hollow out inside and carefully trim out to exact fit. I know someone out there has an easier solution to making these washers, but for me it was all I could find and they appear to work rather well.

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Subject: Washer 2" Diagonal for Rotation --part 2 of 2   Top

From: Keith Graham

With regards 2" diagonal washers, I used a lid from a margarine dish (a plastic coffee can lid would work as well). Being a woodworker, I have a set of hole saws, and I used them to fabricate my washer. I placed the lid on a block of wood with the inside facing up. I then screwed the lid to the block at 120 degree intervals around the sealing lip. Using a 1 *" (you'll need to measure yours carefully) hole saw with a pilot drill mandrel, I bored a hole in the lid. I then put a 2" hole saw on to he mandrel and using the pilot hole as a guide for the pilot bit, I was able to cut out a washer with a thickness of about *". The washer just stretches around the flange of the diagonal with a snug fit. The *" thickness allows clearance for the threaded slip ring. When mounted on my 12" LX200, I can now tighten the diagonal without having it jam, and I can tighten it just enough to get a tight rotation of the diagonal without having it seize up. Admittedly the slip ring may loosen a little as I turn the diagonal, but a little tightening puts it back. That is a small inconvenience compared to the many times I have had to deal with it seizing up.

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Subject: LX200 Cooling Fan   Top

From: Chris Heapy <Chrisha_teasynet.co.uk>

The big Maks have one -- why not the LX200's? Well, now mine has -- and you can see it here (bottom of the page):

<http://easyweb.easynet.co.uk/~chrish/lx_misc.htm>
  Note should open a new browser window over this one.

I still need to find a filter material that doesn't restrict airflow too much.

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Subject: SCT Cooler by Lymax   Top

From: Mike Fuller <mfuller1a_tsatx.rr.com> Date: Feb 2002

I own a SCT Cooler, <http://www.lymax.com> and it works very well. I have not had any problems with introducing dust or such particles into the OTA. It does speed the cool down time. When I bought mine, it came with a filter installed and a pack of additional ones. It runs off of 12VDC.

Generally, the way I put it into the OTA is I remove all my accessories except my 2" diagonal attachment (I have a Televue Everbrite, which includes a 2" barrel that screws on the SCT threads into which the diagonal slides). The SCT Cooler is sized such that you can insert it all the way in and then use the thumbscrew to hold it in place just as you would your diagonal.

I've been happy with mine, though I must say I don't use it all that often because of the humidity down here. I'm less worried about dust and more worried about moisture, as the device does not dry the air on the way in. The people who make it once told me they were considering possibly designing such an attachment for it in the future. Editor's note: see the discussion of cool down times in the Collimation, page 1, topic.

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Subject: GPS Attachment for LX200 Classic --part 1 of 5   Top

From: Doc G, Date: July 2004

Every once in a while one come upon a new toy that is very nice. I can attest to having used the StarGPS on an LX200 and found it worked just as advertised. I put it on an LX200 at a known location and found that it gave that location to a few meters. It is easy to use and would be a nice attachment for the X200 scopes. it takes care of the location information like a champ.

See it at: <http://www.stargps.ca/>

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Subject: GPS Attachment for LX200 Classic --part 2

From: John Mahony <jmmahonya_thotmail.com>

>From: Alan Voetsch
> Hey Doc, any idea how much a small
> increase in location accuracy would help the pointing?

Very little. Once you've done a 2 star or polar alignment, the scope's pointing reference for the sky is set by those two stars, so your location on the ground has no effect except for:

1) very near objects (parallax effect). But in practice, only the moon is close enough for this to be an issue, and you shouldn't have any problem finding the moon!

2) atmospheric refraction: the LX200 corrects for this when pointing, but it's only an issue near the horizon. The scope needs to know your location to determine where your horizon is relative to the sky. If your location was grossly off, the scope would be applying refraction corrections incorrectly, so you'd get pointing errors near where the scope _thinks_ the horizon is, and also near your real horizon. You'd also get "object below horizon" error messages when trying to GoTo some objects that are really above your horizon. But if the location error is reasonably small (under 100 miles), this would only be an issue very close to the horizon.

If you attempt to do only a 1-star AltAz alignment, then levelling, location, and time all become critical.

I don't see much use for the StarGPS device unless you routinely travel large distances with your scope.

For those interested in being picky, I need to amend this slightly. When doing a polar alignment, when the scope does its offset move to Polaris, the hour angle of Polaris will depend on your location/time. But Polaris is so close to the pole that any reasonable error (<100 miles, or within maybe 10 minutes time) has minimal effect. And this assumes that you use only the "standard" polar alignment method in the manual. The "iterative" process, or drift aligning, or most other methods, will correct this error.

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Subject: GPS Attachment for LX200 Classic --part 3  Top

From: Doc G

I have found so many people enjoy their GPS units. There too if they are on a road they know where they are. So who needs a GPS unit at all. Still it is nice to know where you are setup at many star parties that are not on the road. For real science, like finding minor planets, you need to know your position and time very accurately. No harm in getting settings accurate.

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Subject: GPS Attachment for LX200 Classic --part 4

From: Kevin Wigell <kwemaila_ttwcny.rr.com>

I have to admit this product has me a little mystified. But then I was also mystified when Celestron and Meade came out with the GPS feature as well. IMHO, it's more of a gee-whiz feature than one that adds real value. I'm sure some others (especially owners of GPS scopes) may not agree with me.

As an owner of a classic LX200 since 2000, I've learned that performing a good 2-star alignment (or a 1-star when on the wedge) is all that is needed for accurate pointing. Exact time and exact location are almost never required. In fact, all the exact time and location information is used for is to calculate the location of the local horizon, for the purpose of determining which objects are "up", and for calculating atmospheric refraction factors. If one is off by a small amount on the time or earthly coordinates, the error introduced by this will be much less than the normal pointing error for most LX200s.

In addition, the StarGPS product is offered as an add-on for GPS (as well as classic) LX200s. Why would anyone want to purchase an add-on GPS for their GPS LX200?

I'm sure that many people will want to purchase one of these products to bring their classic scopes up to GPS "state-of-the-art", but given that exact time and location are not necessary for accurate pointing, I really question what value it adds. So, as for me, I think I'll save my money.

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Subject: GPS Attachment for LX200 Classic --part 5 of 5  Top

From: Bill Keicher <wekeichera_tcomcast.net>

Having correct position and time is most important for open loop acquisition and tracking of satellites. Consider observing a specific daylight ISS transit of the sun - this happens in a relatively small region. Did anyone see the rare image of the simultaneous transit of Venus and the ISS across the sun as observed in Slovakia and published on the web?

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Subject: Trim or Not to Trim the Secondary Baffle for Improved Air Circulation --part 1 of 4  Top

From: Peter Erdman <erdmanpa_terau.edu> Date: Dec 2002

As is mentioned below, the baffle design on any Cassegrain is a series of important compromises. In an effort to keep the size of the central obstruction low (one possible compromise), Meade has already minimized the secondary baffle.

You can easily observe this. Remove everything from the back of the scope, point it at an illuminated wall, and look up the central baffle towards the secondary. Examine the field of view extremes. You will be just able to look past the secondary baffle directly at the wall.

What this means is that the extremes of the focal plane can be illuminated directly. Light at the edges of the field of view does not even have to pass through the optical system (except for the corrector). Any such alternative path of course leads to much scattered light if there is any significant source in this alternative path.

From: Cary Chleborad
Here is the question: The secondary in my LX has a light shield on it made of plastic or something like it. The secondary is set back into this shield or housing about 1" deep. I am thinking that the recirculating air system would work best if the laminar flow of air across the secondary actually reached the surface of the secondary. As it is now the air flow might be missing the mark. What do you all think of me trimming the light shield down close to the surface of the secondary? Will this cause a problem with reflections or scatter or would it have little to no affect?-----end of quote------

Proper Baffling in a Cassegrain configuration is pretty important. I wouldn't just hack away willy-nilly. If anything the existing 1" baffle might be too short already. The thing to do is draw up a basic optical path layout for the biggest field of view eyepiece, CCD, or film camera you regularly use. This will tell you what you can do with the secondary baffling. My gut guess is that it's already compromised because of the design is made as "all-purpose" as possible. If anything, their might be ground to gain by increasing the baffle length.

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Subject: Trim or Not to Trim the Secondary Baffle for Improved Air Circulation --part 2  Top

From: John Hopper <JohnLX200a_taol.com>

David Olmstead writes:
> I am thinking that the recirculating air system would work best if the laminar
> flow of air across the secondary actually reached the surface of the secondary.

First, I'd put on more powerful fans to make sure the flow was turbulent rather than laminar during initial cooldown. A slow laminar flow sounds better optically but isn't doing nearly as much for heat transfer. Is the fan intended to be on all the time, or just to force cooldown initially? Better yet, you'd want two speeds for those two very different purposes, plus an "off" switch in case of mechanical vibration.

> As it is now the air flow might be missing the mark. What do you all
> think of me trimming the light shield down close to the surface of the
> secondary?

I don't like the idea, it sounds like a bad trade-off.

The mass of the secondary is almost negligible compared to the primary. I'd bet that any old amount of air reaching the secondary will be good enough to keep the primary as the weakest link in thermal problems. I think that if you even TRIED to design a system to keep the air from getting to the secondary, it might still get there well enough to work better than the primary.

Making this doubly true is the physically smaller size of the secondary surface. I'd bet that the equations behind any accumulated surface distortion are probably dominated by terms which include functions of radial size, because this is the distance across which an axis-symmetric temperature gradient is able to act.

> Will this cause a problem with reflections or scatter or
> would it have little to no affect?

That depends on whether Meade designed it well. I'd leave the secondary alone and worry more about the primary and even the corrector plate more. Mind you, it's been a while since I've calculated a Reynolds Number in my head, much less the heat transfer from forced convection.

> I hope I have explained this adequately--kind of hard without pictures.

It sounded pretty clear to me. My only questions are about when the fan is intended to be running or not, and whether it's just one speed or not.

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Subject: Trim or Not to Trim the Secondary Baffle for Improved Air Circulation --part 3  Top

From: David Olmstead <davida_tdavidolmstead.com>

This fan system is intended to be used as a follow up device after the initial cooling, which is done by an intake fan already mounted on the back of the OTA. The rear mounted fan already in place is used in tandem with an exhaust fan which gets connected to the tailpipe, exhausting air through the central baffle. I have those fans filtered, but not with ultra fine filter material.

To my knowledge the original designer of this new project, Mr. Lawson, runs this recirculating system while viewing, and uses a rheostat to adjust the fan speed to minimize vibration. The fan assembly brings in no outside air and simply stirs the atmosphere inside the tube, no filtering is necessary. I have read a bit about boundary layer issues with our scopes and how disrupting that layer right over the primary can improve views. My thought was that while I was stirring the atmosphere inside the tube why not try to direct the flow some by having the air move over the face of the optics with the hopes that the boundary layer would go away. The fans will also be isolated some by the use of rubber washers inside the new fixtures that have been made--maybe that will help with bothersome vibration along with the adjustable speed.

I will follow some of your thoughts and not trim the secondary baffle down. I will leave it as is and direct the flow across closer to the corrector instead, and of course across the primary too. Mr. Lawson wrote that the mixing of the air inside the tube to a homogenous consistency really improves the bad seeing inside the scope itself, we will see!

I have not found a web resource for this mod. To my knowledge the only place to find out about it is an article in a publication called "Amateur Astronomy". The issue is #31 - Fall 2001. Again this is not your typical rear mounted CPU fan approach, but instead a sealed recirculating system. It does not bring outside air into the OTA.

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Subject: Trim or Not to Trim the Secondary Baffle for Improved Air Circulation --part 4 of 4  Top

From: Doc G

David, you have received excellent responses to you plan/question. I can not add much, but strongly support these comments. I would say to use the fans a very minimum amount of the time for two reasons. One is vibrations of the OTA from the fans. They are generally not very well balanced. Also minimize the time you use them because the additional air flow introduces dust and an accumulation of dust take place where the air is moving the fastest. Do not count on ordinary filters to take out the dust. Micron level filtering is required to take out the dust. This is not easy to accomplish.

In other respects, moving some ambient temperature air through the scope is a good idea. I have the same scope 10" f 6.3 and the baffling is already minimal.

rule

Subject: Setting Circles on LX200  Top

From: Jon Brewster <jon_brewstera_tex.cv.hp.com>

>Can any one give me some pointers on how to use the setting
>circles on my Meade 10" LX50? I tried to use them the other
>night and had good luck w/ the Declination but was way off in
>RA. Any pointers or sites out there for the newby?

I have worked this out for my LX200. I do not know whether it is the same for the LX50, but here it is anyway as a cut / paste from my web site:

The RA circle is really clever. The circle sits between the scope and the base, and each of the scope and base have an index mark. The circle can be manually turned independently of everything. When the scope is unclutched for manual RA turning, then the circle stays with the base. When the scope is moved with keypad, then the circle moves with the scope. There are three ways to use the circle (the third one is way cool). These explanations assume northern hemisphere, so ignore the inner dial numbers and use the outer dial numbers only for both scope and base indexing. Also, a polar aligned scope is assumed.

  1. When using the LX200 in its full electronic GOTO mode, the circle looks good but is useless. Treat it as a decoration. It cannot be read for sidereal time or RA when in this mode.
  2. When using the LX200 with no power:
    - turn the circle until the base index mark reads the current sidereal
    time
    - unclutch RA axis and turn scope (with manual knob if desired, and / or with clutch partly engaged to provide some friction). The scope index mark can be used to read current RA.
    - manually move circle to keep up with sidereal time as needed
    - alternatively, one can set the RA of a known object by moving the circle into alignment with the scope mark then immediately turning the scope to the desired RA again using scope mark)
  3. With a powered scope that is not going to be used in GOTO mode, but is intended for "manual finding" (perhaps for practice) something nifty happens. Whether the RA clutch is engaged or not the circle actually keeps tracking clockwise with the stars, such that it will continually read sidereal time on the base index and the scope index will always read an accurate RA. (Unless you do a GOTO, then you're back to mode one above).
    - power-up and read sidereal time off the keypad then put the keypad out of the way leaving power on
    - manually turn circle so that base index mark reads sidereal time (as long as the keypad or a computer is not used to move the scope, it will keep reading sidereal time) - manually move scope reading RA off the scope index mark ... all night long.

rule

Subject: Spiral Search Function for LX200 Classic? --part 1 of 3 Top

From: Scott Pinkham <scottpinkhama_tearthlink.net> Date: Sep 2003

-----Original Message-----
From: Joachimp:
I have a LX200 classic and wonder if there is a spiral search option on
the scope. If not, do you know of a freeware or shareware that
offer this function? I use a laptop to control the scope.
-----End of Original Message-----

Joachim -You can try out my free "ScopeControl" program:
   <http://www.geocities.com/scottpinkham/astro/astro_main.htm>

It has a spiral search function that I use routinely to get objects onto the small field of view of my CCD camera -- the field of view and dwell time are adjustable. I'm working on making it also function as a plug-in for Starry Night.

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Subject: Spiral Search Function for LX200? --part 2

From: James Macak <jmacaka_twi.rr.com>

AstroPlanner does a spiral search...
AstroPlanner 1.3 for Macintosh and Windows is shareware by Paul Rodman. Highly recommended!
Find it here:
   <http://www.ilangainc.com/astroplanner/>

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Subject: Spiral Search Function for LX200? --part 3 of 3

From: Paul Rodman <paula_tilanga.com>

It sure does. It bases the "spiral" on the FOV of your eyepiece/scope combination, assumes a 50% overlap, and moves one leg of the spiral each time you click the button. Compatible with any Goto scope supported by AstroPlanner. It is a new feature in V1.3.

rule

Subject: Moisture Removal from OTA  Top

From: Michael Cook <michaeljcooka_trogers.com> Date: Jan., 2001

Doug Azwell wrote:
> Someone on the list recently mentioned modifying a film canister to
> hold desiccant gel to help keep moisture out of the optical tube.

Drill out 8 or so holes out of the bottom of a 35mm film canister. Place some desiccant into a small cotton bag, tissue, or some other filter material (you don't want desiccant to get inside the scope). Place the bag of desiccant in the canister. The canister fits nicely into a 1-1/4" adapter. Moisture inside the OTA will be wicked up by the desiccant.

rule

Subject: OTA Bolt Removal Suggestions  Top

From: Doc G, Date: Feb 2002

Bob Genung wrote:
> I've got a real problem I hope someone who has perhaps done the Dec. bearing
> mod can help with. I'm in process of trying to remove the OTA following
> Michael Hart's procedures as shown on Doc G's website.
> Major problem: no matter how much I seem to blowtorch the two
> Loctite-secured flat head stainless steel Allen screws on the inner clutch
> plate, they remain frozen solid! I am indeed now scared to death of
> damaging the screw head. I've also painted the two screws with debonder,
> but I suspect a fair amount of Loctite was placed on the screws at the factory.

These screws are stubborn. If you have damaged them, you may need to cut them out. Here is the way to do this:

Get an Allen wrench of the right size with a handle. It is essential to have a new wrench since Allen heads are easily stripped. It is almost impossible to get them out with one of those dinky L-shaped wrenches. The clutch plate gets too hot, and you cannot get enough force to turn the screws. Apply a small but hot torch flame to the screw head for as long as 1 minute. Get the flame tip, the inner cone tip, which is the hottest part of the flame, right to the face of the screw. Press the wrench in to the socket very strongly and twist. The screw will come out.

Remember that the clutch plate is a large mass and carries the heat away easily. The clutch plate will get too hot to touch. The screws will come out. Most persons are too timid and afraid to apply enough heat. Remember a hot flame and quick action with the wrench. There is nothing that will burn up.

On the other hand, if you are simply going to remove the OTA, it is easiest to remove the screws that hold the OTA to the saddle on each side. Then loosen one of the forks and the OTA will slide right out. Be sure to have someone hold it while you loosen the fork arm.

On the other hand, if you insist on removing the screws, first try the "lots of heat" method and the strong, new, Allen wrench with a handle. If you have totally ruined the screw head, cut a deep slot in it with a Dremmel carbide disk and use a flat screw driver to get it out. You will still need lots of heat.

As a very last resort you can drill the screw out, but you will then have to deal with a stub that will be very hard to get hold of. And you will still need lots of heat. I strongly advise trying to get one of the first techniques to work. Just pretend you are trying to burn the darn thing down. You can apply heat for well over a minute in some cases. The Loctite will eventually melt and the screw come right out.

rule

Subject: Rusting Screws -- Replace or Recondition? --part 1 of 2   Top

From: Gene Horr <genehorra_ttexas.net>

Wayne Watson wrote:
Some of the screws on my LX200 are gathering a bit of rust. I would think a little
steel wool might work, but what about preventing rust in the future? I recall
somewhere in the distant past something about wax.-----End of Message-----

Personally I did the same as David and replaced all with SS. If you have a true bolt supply house nearby the price isn't that much. Retail hardware stores have a huge markup (at least 400%) and so that way can get pricey.

If you want to retain the original bolts just wipe down with LPS 3. You can get it from any machine tool supplier and most Ace Hardware stores. Worse case you can order it from Mcmaster-Carr <www.mcmaster.com>. I live in a high temp high humidity area and this product works great.

Cosmoline is probably the best coating but personally I hate that gummy stuff. Pay the extra money and get LPS 3.

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Subject: Rusting Screws -- Replace or Recondition? --part 2 of 2

From: Greg Jones <NGC2841a_tpacbell.net>

Stainless steel screw kit for LX200GPS, LX200, LX10, LX50 and LX90 OTA are listed at $14 for a kit at ScopeStuff: <http://scopestuff.com/>

click on category "Upgrades and Maintenance" then scroll down to "Threaded Things" and click on "Rusty Screws Replacement Kits for LX200GPS, LX200, LX90, LX10, LX50".

rule

Subject: Removing OTA from Forks   Top

From: Roger Hamlett <ttelmaha_tntlworld.com> Date: June 2002

----- Original Message -----
From: Al Brockman <alanba_tcscoms.com> OTA Removal?
> At great risk of exposing my mechanical ignorance, is there a relatively
> simple or straightforward way to remove the OTA from the forks of the
> LX200 without dismantling the DEC assembly?

In the procedure for removing the OTA, you don't have to touch the Dec assembly, but you _do_ have to take one of the fork arms 'off' the base of the scope. The entire arrangement, is that the plates on each side of the scope tube, are held by three screws each. Once these are undone, the tube is still (slightly) held, by a little pressure from the two arms, and will not come out, since the ends are larger than the tube. Hence the base of one arm has to be undone to allow the final removal. Now at this point come the 'caveats'.

Firstly, it is safer to have the whole assembly on it's side, so that the tube is resting on one arm, and then remove the 'top' arm, so that there is less risk of dropping the tube...

The second 'caveat' though is alignment. There are three seperate points, in the removal, that require very accurate re-alignment if the scope is ever to go back together again, and work properly.

  1. The two plates on each side of the tube have oval holes on their bolts, and the tube can be adjusted fore/aft in these plates, and rocked slightly.
  2. The two shafts, must be in line when re-assembled, or tracking will degrade, and simple 'marks' do not provide sufficient accuracy.
  3. The base of the fork arm is similarly a critical alignment. At this point the arm can be raised/lowered, and also rocked. Again alignment here is critical if the system is going to actually track properly.

So there are three seperate locations, and each can move in two different ways, that must all be re-aligned for the system to work as designed. There are descriptions of how to do these alignments using 'optical' methods (which are needed if the alignment is to be really acceptable), on this site at "Optical Tube Alignment", Doc G's site, and see below. You should be 100% happy that you can do the alignment before slackening any of the screws...

----------------------------------------------------

Subject: Removing OTA from Forks --afterwards   Top

From: Mark Simpson <zawada-sender-1e3340a_tbowfort.com>

Here is some information that will help you get all lined up again afterwards back to your original accuracy, heck you might even get it better.

I would add, although marks on the forks and OTA won't get you back to the original alignment (not even close), but use them, because it will get you in the general area and save you a lot of time.
    <http://www.aurorachasers.com/Astro/Lx200Alignment>

Editor's Note: also see topics "Aligning OTA", another "Aligning OTA", and "Alternate Aligning" here in the Topical Archive

rule

Subject: LX200 Accessory Attachment Screws    Top

From: Roger Hamlett <ttelmaha_tntlworld.com>

David Samuel <samuelda_tbigpond.net.au> wrote:
>I have a 12" LX200. It has hex head (or something like it) screws
>around the optical tube on both the corrector plate and the mirror
>cell end. I wish to attach other equipment such as a guide scope,
>accessory bar, etc. to the optical tube. There are two sizes of screws -
>large and small. My question is which screw holes do I use to attach things to--
>the large ones or the small ones?

Normally the large ones. Whichever you use, provided you only remove one, or at most two screws at a time, the rest keep things held together. Standard attachments, like the Losmandy rails, or counterbalance systems, normally use the pair of larger screws that are about three inches 'each side' of the centre line of the scope.

rule

Subject: LX200 ScopeSaver/Mounting Assistant      Top

From: Bill Wood <wrwooda_tqwest.net>

After my first week with a new LX200 10", the most annoying problem has been the extreme difficulty of mounting the scope on the tripod. The attachment rod sticks up from the center of the tripod requiring great aim to get it in the corresponding hole in the scope base. Apparently my aim stinks since I struggled with it most every time.

The Springy Thingy idea from MAPUG archives looks like a good solution but I wanted a place to hang the control pad so a plate type arrangement seemed better. I have followed all the posts about ScopeSavers with great interest and even called Meade for suggestions. (Meade said forget the ScopeSaver, just practice getting the rod in the hole.) I shied away from the ScopeSaver as pictured in the Shutan adds because they are just too big and I would never put eyepieces in it anyway since they might get wet, dirty or knocked out. Then I spotted the Mounting Assistant from Pete Peterson:
   <http://www.petersonengineering.com/SkyDiv/MA.htm>

The Mounting Assist was very close to what I wanted but since it was made from 1/4" aluminum plate the rod still sticks up hence you still have to hold the weight of the scope while you place it up against the alignment stops to get the rod in the hole. I wanted to just put the scope on the plate anywhere it falls then slide it into a stop that centers it over the attachment rod.

So I basically copied the Mounting Assistant using a 10"x12" piece of 1/2" white Corian - the stuff kitchen countertops are made of - which is quite slippery. Corian can be cut and routed with ordinary carbide tipped woodworking tools. I use high speed steel bits to drill it. Then I flipped the black aluminum leg spreader over at the suggestion of another brilliant poster and it works perfect. If you don't flip the spreader over the rod is too short but you can adjust it perfectly with the spreader upside down. The 1/2" Corian is just a hair thicker than the height of the rod so you can simply plop the scope down anywhere on the platform and slide it up against the stops which center it over the rod.

Incidentally Meade put the nut on the attachment rod handle on the wrong side. You can eliminate the Locktite on the attachment rod handle by simply putting a 1/2" nut up against the inside of the black handle. Adjust the rod length so the C-type does not protrude above the surface of the new plate and snug the bolt against the handle and it will stay tight forever with no Locktite or glue. The Meade nut can stay on the outside of the handle as a decoration. Unlike the Mounting Assistant, I used only 2 stops, 1 in each rear corner, since 3 are unnecessary and it would be almost impossible to get 3 lined up so they actually touched the scope base anyway.

I can now put the scope on the tripod in the dark in 2 seconds every time. Definitely worth the 3 hours I spent putting it together.

rule

Subject: LX200 Scopesaver Website      Top

From: Bill Boyd

They now have a web site at this address:
    <http://www.scopesaver.com/>
    Note: should open new window over this one.

rule

Subject: LX200 Saddle Mount --part 1 of 2    Top

From: Doc G, Date: Mar 2004

I have added a small section and description of the LX200 saddle mount I have been working on. I have now completed it and have a second one being worked on. The original idea is due to Ted Agos. I think this is an exciting way to use up some of those old LX mounts. This article describes my personal set up

The other thing about the saddle, in addition to its versatility for holding any lens, camera, telescope or what not, is that you can attach a very inexpensive webcam type guider to one of the telescopes. Then in equatorial mounting of the LX200 mount you have a perfect imaging setup for even quite long term exposures.

The webcam can be run with the Guide Dog program very successfully. (or several others)

-----------------------------------------------------

Subject: LX200 Saddle Mount --part 2 of 2     Top

From: John Mahony <jmmahonya_thotmail.com>

Since you mentioned GuideDog, I'll forward the following message, just posted today by GuideDog's author on the LX200 yahoo group:

A new version of my GuideDog autoguiding software is available for download.

New features of Version 1.0.4 include:

  • Support for Parallel Port based relay boxes such as Etienne Bonduelle's interface at:
    <http://www.astrosurf.com/astrobond/eblxinge.htm> allows guiding of most mounts with a CCD Guide Port including the LX90 with APM interface
  • Ability to run a relay box and SC-modified webcam on a single parallel port
  • Configuration support for SC-2 (AdvancedMOD) and SC-1.5(AmpOff) webcams
  • Added individual guide rate configuration settings for both RA/Dec
  • Addition of backlash adjustments for both RA/Dec
  • Minor bug fixes

A new website <http://www.barkosoftware.com> has been created to host GuideDog as well. This site will be dedicated to astronomy and astrophotography related software that I intend to develop.

The website also features a discussion forum where GuideDog users can discuss/post questions and issues with various mounts/cameras/scopes.

The new direct link to GuideDog is <http://www.barkosoftware.com/GuideDog>

rule

Subject: LX200 Quality Vs. Celestron's      Top

From: Rick Richardson

>>Bob Moorman wrote: If Meade's service is that bad, and the equipment failure rate high, perhaps I should look elsewhere. I'm a little hesitant to purchase the LX200 until the bugs, of which there really should be none at that price, are worked out. Any idea of the quality of Celestron? The advice in reference to SBIG is taken. Wonder how their service department operates? Both SBIG and Celestron? I, like everyone else, wish to get the most for my dollars.<<

The quality statement is odd to me since S&T and other mags think the LX200 excels in astrophotography. Remember Celestron just changed their line of scopes, so Meade is reacting to them. The overall capability of the LX200 is considered to be higher than Celestron's last line of high-end scopes. The newest ones the verdict is not in. The software even old in the LX200 and the AutoStar II are supposed to be miles ahead of Celestron, though narrowing from what I have seen. I researched this for over a year. I tracked Celestron, Meade, TeleVue and Orion. I wanted an intelligent scope with great optics.

A friend has a C11. We both purchased in July. We have friendly competition there. The scopes are often setup side by side. His optics are fine and the star tests seems much the same, but his is not as stable in the wind or with touches. I track satellites far more smoothly. Though M31, M45 or Jupiter are beautiful through both. We both went SCT because we wanted aperture and some portability. We both want to do astrophotography in the long run.

I decided to start visual because the cameras were changing rapidly, and as electronics will get far cheaper fast. I figure in another year when I have finished more research I will buy my first camera, but I am very happy with my choice of scope type and manufacturer. See how much you will spend and how portable any refractor of 5 or 6 inches with any focal length is. Another buddy has a TV 4" refractor and spent more than my 10" SCT and has no motorized mount.

Anywhere you check overall scope ratings you will find Meade LX200 does as well or better than its competitors. The LX200 has been a barn-burner in sales (understand that is relative within the amateur astronomy field). That should tell you something. People who buy them overwhelming say they would buy again. I have polled. The same was not quite as strong for Celestron, but close enough not to be a problem or a controlling factor. Universally no one likes service at either place. BUT both have to be pleasing their customers to some degree. If only American companies would understand the importance of service in competition.

You should know that one of my degrees is in statistics. I take my polling and research seriously.

What I am trying to say is:

  • There is no data supporting inferior workmanship as a problem for Celestron or Meade.
  • Since the best predictor of future performance in such cases is generally past performance, the Meade LX200 should be just fine.
  • Whichever you pick, you will probably love it.

rule

Subject: LX200 12" vs. Celestron 14" - Comparsion-- part 1 of 3     Top

From: Al

----- Original Message -----
From: Nigel Bannister <npba_tstar.le.ac.uk>
> I'm on the verge of buying an LX200 - most probably a 12". However, I've
> also been looking at the Celestron CM-1400 (I note recent adverts show a
> NexStar version on the way). I'm sure there must be people on the list who
> have had to make the same decision - so I'd be interested to know why they
> chose one over the other. Initially I'll be observing visually, but I intend
> to do some CCD imaging eventually. The few comparisons I've read suggest
> that optical quality is excellent in both models. Looking at the brochures,
> however, the Celestron mounting looks very flimsy for such a huge OTA (even
> if it IS carbon fibre), and I worry about stability. But I've also read
> comments on the list about the LX200 12" combo and mechanical stability, and
> gather some very well respected and experienced users have chosen to put the
> Meade OTA on a 3rd party mount. I don't have the cash for a Paramount... but
> there appear to be mechanical stability issues with both models, albeit in
> varying levels of severity.
>
> I'm already a Meade owner (LX6 10"), and I'm impressed with the degree of
> support from the community (e.g. this list), which Celestron doesn't seem to
> have (oh, and I like blue) so despite feeling the effects of aperture fever,
> I'm biassed toward the Meade - but I'd value any comments or observations
> MAPUG members have on this particular comparison - personal accounts of
> using the Celestron would also help.

If this list is anything like others, you're going to read many posts on this subject, many of which will tell you that the CM-1400 does not cut the mustard (most of these from people who do not own the CM-1400). I suggest that you digest this information with a grain of salt.

I own and use a CM-1400 and a 10" LX200 (similar to the 12") and can tell you that both are fine scopes, and both scopes have a set of downsides. Here are some points of comparison:

OTA - The optics of both of these scopes are very good (as far as SCTs go), but the extra 2" of aperture gives the C-14 a significant plus. More importantly, the C-14 has a feature (Fastar) which puts it head and shoulders above the LX200. Fastar is a very important consideration if you plan to do imaging down the road. Think about the virtues of imaging at an incredible F/2!

In spite of the size of the C-14, I find that this scope has a significant edge over the 12" in terms of manageability and ease of set-up. Neither of these scopes can ever be considered portable (if you want a portable scope, it's best to get something smaller) but the CM1400 is easier for one person to handle. The heaviest part of the CM1400 is the OTA, which weighs in at just under 50 lbs. (the newer ones should be lighter). In comparison, the 12" LX200 OTA/fork weighs over 70 lbs.

Mount - I give the plus here to the CI700. I agree with those who say that this mount is not beefy enough to support a C-14 for the purpose of imaging, however, for visual use and for imaging in Fastar mode, the mount is close to ideal. Besides, moving a step up in large mounts will cost up to $9K or more, compared to the modest price of the CI700.

The bottom line, however, is what you think of the performance of these scopes in action. I suggest that you take your time and take a test drive before you buy.

---------------------------------

Subject: LX200 12" vs Celestron 14" - Comparsion-- part 2      Top

From: Jack Dembicky

I don't have much personal experience with the C-14 but I do own an 12" LX200. I am not going to suggest that one scope is better than the other as I think both are fine and photographs taken from both prove this point.

One of our local club member does own the C-14 on a CI700. mount. He has a lot of problems with the mount (not the telescope). Either he has a bad one or he has just had more than his share of problems with it. If you would like I could send you his e-mail address privately and you can ask him specifics about the C-14/CI-700 mount. This is NOT the new GOTO mount from Celestron and I am not certain if they changed/improved things on the mount or not.

Anyway, I was talking to him about the same exact topic last weekend and he told me that he gained (too late unfortunately) a lot of useful information from the Yahoo! Group CI-700
   <http://groups.yahoo.com/group/ci700_users/>

They would be more knowledgable about pros/cons with the mount specifically. I think there are also Yahoo! groups for the C-14 and I know several for the Meade, including the
   <http://groups.yahoo.com/group/30cmSCT/>
which is for bigger SCT telescopes (and not specific to Meade). Just got to:
   <http://groups.yahoo.com/> and do a search for Meade, C-14, etc. to find them.

As for the weight issue, both him and I are pretty big guys and handling 50-70 lbs. is not an issue. On the LX200 if you are going to use it in Alt-Az mode then I have never found it much of a problem getting it on the mount easily (well you have to be able to pick 70 lbs. up to about waist height (the base of the telescope fork mount to the top of the tripod.). Putting it on the wedge is a bit more difficult as you have to pick the telescope up to about shoulder height (I use my shoulder to hold put one fork against) and slide one bolt on the bottom of the fork into the wedge.

A key in using the mount in Alt-Az is to align the legs/spreader/center spreader bolt for the mount BEFORE you put the telescope on the tripod. I align the spreader so that the tripod legs are situated correctly and the rod will go up and down the center hole in to top of the mount freely, then I pick the scope up (and not moving the mount, it's pretty heavy and stable to not move) place it on top of the tripod. All you have to do then is slide the telescope/fork base until it aligns with the spreader bolt hole and screw/tighten the spreader bolt into the fork base. I can usually have the telescope mounted in a minute as long as the tripod is set up / spreader bolt aligned before hand (which is pretty easy to do with no telescope on it), that's the key to mounting this telescope on the tripod.

--------------------

Subject: LX200 12" vs Celestron 14" - Comparsion-- part 3 of 3      Top

From: Gene Horr <genehorra_ttexas.net>

My experience is that the optics in both are comparable.

But as Chas mentioned the mount is seriously under the strength needed for visual work much less imaging. Again, as Chas mentioned the AP1200 would be great for this instrument. Some other mounts to consider would the Losmandy GM-200, Mountain Instruments MI-250 (maybe...I would try to find people who have used this setup) and the Takahashi NJP. But all these add up to at least a couple of time the price of the LX200, although you do get a much better system.

Unless you plan on keeping the C-14 for the rest of your life or are planning serious imaging in the future I would lean towards the LX200.

rule

Subject: Supercharging (rebuilding) Service   Top

Dr. Clay Sherrod does a "Supercharging" of LX200 scopes...you can get a major rebuild done.
    Try: <http://www.arksky.org/supercharge.htm>

rule

Subject: LX200 Scope Repair Service   Top

From: Doc G

There is now a company called "TelescopeService." <http://www.telescopeservice.com/>

I have been in contact with Tim Prowten, and feel they are fully qualified to carry out service on the LX electronics. They are genuine electrical engineers who have reverse engineered the electronics and seem to have found sources for the parts, a number of which are obsolete and hard to find. Have heard that it's best to call rather than email.

rule

Subject: Will Meade Upgrade Old Optics to UHTC?   Top

From: Keith <keithnka_tprodigy.net> Date: Feb 2005

I believe you are right that there has been no official press release or public advertising, but in fact they do offer optic upgrade for older scopes. You have to call customer service and make arrangements. However, you may have to be persistent. Not everyone in customer service knows that this option is available. I called 3 different times and got 3 different answers, and had to be persistent to get the last one (David) to discover that yes it can be done, and then set it up. If you have any trouble, get to John Piper, the customer service supervisor. Talk to him directly (usually not possible) or leave a message to have him call you back.

I have made the decision to get the optics of my F/6.3 10" replaced and persisted. Here's the scoop on that scope, and an 8" F10.

LX200 (1997 vintage) F6.3 (rare, and no longer made) 10"
Standard coatings = $550
UHTC coatings = $785

LX200 (1999 vintage) F10, (very common) 8"
Standard coatings = $450
UHTC coatings = $625

You pay shipping out, they pay shipping back, quoted turn around = 7 days, you get an RGA (Return Goods Authorization) number. You can pay for it (up front of course) via credit card or check.

The UPS store has a box about the right size for shipping either the 8" or 10" LX200. It needs a little additional bubble wrap around the original foam to make a snug fit.

One further note, I asked if I could remove the old optics before shipping the OTA out to receive the new ones. Nope. It's an exchange of old optics for new.

rule

Subject: Adapting 12" Fork Assembly to a 10" OTA   Top

From: Doc G

D. Cobb wrote:
> I have a fork/drive base assembly from a 12" LX200 in which
> I plan to mount an older 10" OTA from an LX6 to produce a
> 10" LX200 for our club observatory. Removing the spacer
> blocks from the fork arms should result in the proper fork
> width to hold the 10" OTA. Since the side plates for the
> 12" will not properly mate to the 10" tube, I plan to reuse
> the side plates from the LX6 mount. (I'm calling the pieces
> which attach directly to the tube the side plates.)

I have taken apart and modified a number of 10" and 12" LX mounts. You are facing many very difficult incompatibilities between the 10" and 12" mounts. The 1" shaft which enters the bearing on the scopes is a cast and then machined part of the saddles. (what you call the side plates). Unless the saddles you plan to use have a 1" shaft, they will not be compatible with the forks from the 12" mount.

Also, the spacers are not a simple push in place piece. You will not be able to simply take them out and then attach the forks to the base. There are considerable difficulties in doing what you propose. I suggest you dismantle everything and then look carefully at the parts to see what will and what will not fit. Dismantling is not difficult if you follow the direction given on my website.

rule

Subject: Vibration Suppression Pad Orientation -- part 1 of 2   Top

From: John Hilliard <j_hilliard848a_tbellsouth.net> Date: June 2005

We have never tried the Meade VSP's (vibration suppression pads), or those provided by anyone other than Celestron.

We have been using them for several years and have noted a definite 'Visual' difference. The only problem we have had with them is occasionally the little nugget of Sorbethane(?) pops out of one of them but it drops right back in and life is fine.

There actually is a proper orientation for setting these things under the tripod. There are three little beads on the bottom of the hockey puck that they rest on. Two should be facing away from the center of the tripod and one facing in. We keep the rubber tips on the tripod legs. The instructions that came with the VSP's and several articles we have read state they work better with the feet removed but for our purposes the dampening is more than adequate. I am probably more concerned with the weight of the 12" LX and tripod possible slipping to one side and damaging the VSP's since the replacement cost is now back to the $45 a set range and you cannot buy just one. Just personal impressions and satisfaction level.

----------------------------------

Subject: Vibration Suppression Pad Orientation -- part 2 of 2

From: Rick Woods <Rick.Woodsa_tAZDOA.GOV>

The Meade pad instructions say that the Meade logo on the puck must point outward, but offers no explanation. Why should it make a difference, I wonder? I've always done it, but could only guess that it had something to do with the way they wear.

rule

Subject: Lens Cover as Accessory Tray   Top

From: Eric Smith <erica_tesmithonline.com> Date: June 2005

I was looking for a way to increase my accessory tray space. So, I used my lens cover:
   <http://esmithonline.com/astronomy/equipment.htm#lidtray>

rule

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