Alan64

24 minutes ago, vlaiv said:

If you go by the definition: Catadioptric telescope is one combining reflective and refractive elements to form the image at focal plane of the telescope - then you could say that refractor + diagonal is catadioptric telescope.

Then there is different definition: Catadioptric telescope is one using both reflective and refractive elements to shape light into forming an image at focal plane - then flat diagonal is nothing more but device to position focal plane without altering the shape of light beam. It is not altering the waveform in any way (not deliberately / by design at least).

Most people when using term Catadioptric system - thinks second definition, so refractor + diagonal is not considered to be catadioptric telescope.

Most people when using or hearing of the term "catadioptric" do indeed think of the second definition: Schmidt- and Maksutov-Cassegrains, therefore a refractor, with or without a mirrored diagonal, is most certainly not either one of those.  Although, the Maksutov-Cassegrain has been described as being "refractor-like", and is the only reflecting telescope so considered.  A Maksutov is also the only modified-Cassegrain that I would own and operate.  I would also like to have a classical Cassegrain.

29 minutes ago, alanjgreen said:

Actually, SCTs use a special “magnifying” mirror for the secondary. Celestron’s SCT secondary mirror magnifies the image by x5 as well as reflecting the image. That is where the long focal length of SCT come from.

I use a Zeiss Prism diagonal and really like the clarity of the image in my refractor. It is also less prone to reflections generated by bright objects from outside the fov.

Alan

A catadioptric is any telescope where refraction and reflection are combined; lenses and mirrors, whether a modified-Cassegrain(Schmidt and Maksutov), or a refractor with a mirrored diagonal.  If you must use a diagonal with a refractor, always endeavour to make that one a prism; to preserve the "feng shui".  A mirrored diagonal is suggested, however, for f/5 achromats.  In addition, combining a mirrored diagonal with a Schmidt- or Maksutov-Cassegrain is, in effect, adding a third mirror to the light-path, which may only serve to increase the incidence of light-scattering.  

2 hours ago, mikeDnight said:

A good diagonal won't degrade the image though, as if they did, no one would use them. Also, turning a refractor into a catadioptric by the use of a diagonal is like saying a reflector becomes a refractor by the use of an eyepiece. The mirror or prism only redirects the light, it doesn't play an integral part in forming the image as a corrector plate or meniscus lens would in a true cat'. 

It's generally felt that mirrors work best in fast F ratio scopes and that may be true, but a friend of mine uses a Tak prism in his Sky 90 without any noticeable degradation in image quality. You could perhaps find an old circle T prism, which are excellent, and try it out. Some cheap prisms though can be atrocious. I had to atomise at least two Celestron prisms because they delivered putrid images. But cheap mirrors can be equally as bad.

People use diagonals regardless if they are good or bad because it's far more ergonomic.  Straight-through observing is a lost practice for the vast majority, save for the Japanese(at last count).

The secondary-mirror of a Newtonian is that telescope's "diagonal".  Have a look at this "refractor"...

https://explorescientificusa.com/products/products-package-deal-bresser-comet-edition-102mm-refractor-kit-variant-2221347844

That is a catadioptric.  

In so far as a diagonal not degrading an image, think again.  The more you add to the light-path, the greater the chance for degradations; light-scattering in the case of a mirrored diagonal.  Then, there's the miscollimation of either a mirror or prism with which to contend.

When one does place a diagonal into a refractor, you still can't use the telescope until you add an eyepiece, therefore the diagonal, when integrated, becomes one with the refractor, a component of the telescope's light path, and just as the secondary-mirror of a Newtonian; therefore, again, a catadioptric when using a mirrored diagonal.  I suppose, rather, that you might hold that a Newtonian becomes a catadioptric when an eyepiece is inserted; most definitely not a refractor by any stretch of the imagination; however your point is moot, as eyepieces are not an integral part of a telescope's light-path, rather the receivers of the light-path instead.  Observe what happens when the tip of the light-cone of an objective nears an eyepiece...

Note where the tip of the light-cone ends, and just as it exits the body of the diagonal.

Eyepieces are, again, merely receivers, and therefore cannot transform any telescope into another.

This is my 80mm f/6 achromat, but with a 2" mirrored diagonal.  Configured so, it is in a catadioptric mode of operation...

If I take the mirrored diagonal out, and put a prism diagonal in its place, the telescope then reverts back to being a refractor; closer in any event, as some regard the "total internal reflection" of a prism diagonal as just that, a reflection.  However, there is no light-scattering, aluminised coating involved.  In a straight-through configuration, without a diagonal at all, the refractor is at its very best, in form, function, and performance. 

Incidentally, in the case of a barlow, if inserted before the diagonal it becomes a part of the telescope's light-path.  If the barlow is inserted after the diagonal, it becomes a part of the receiver, the eyepiece.

2" mirrored diagonals are more popular not because they're so very wonderful, but simply because they're cheaper to make, and purchase.  I do not look upon mirrors as a cure-all, and as so very many others do.

2 hours ago, Klitwo said:

Speaking of comet hunting brings to mind Mr. William Bradfield of Australia and his homemade 6-inch 100 plus year old Dallmeyer camera lens refractor that was equipped only with an old war surplus 26x Erfle eyepiece mounted on his barn yard rickety looking wooden adjustable height tripod.  However strange looking his 6-inch refractor and wooden tripod setup appeared to the modern day comet hunter....Mr. Bradfield was able to discover "visually" an extrodinary long list of comets that bear his name and his name only.  And interesting enough...he did so "without" the use of a star diagonal....>

https://www.skyandtelescope.com/astronomy-news/bill-bradfield-comet-hunter-extraordinaire-1927-2014/

http://i.picasion.com/pic88/b11d367439789ef9e6c7fc3806230a38.gif

P.S.  Even with all of the modern comet hunting refractors of today that sport the ED glass, top-of-the-line star diagonals and high-end primary mirrors and secondaries that yield nearly 99% reflectivity...including those that are equipped with the latest CCD technology.....it's a good bet that Mr. Bradfield's remarkable list of visual comet discoveries in the modern era will no doubt "not" be surpassed and will be around for a long long time. Whereas most if not all of us would be happy with just "one" comet discovery bearing our name in our life time....Mr. Bradfield had 18.....

Klitwo

Indeed, the addition of a diagonal of any sort can never be an improvement, observationally; only in an ergonomic sense.  However, the use of diagonals has become so commonplace that their omission is practically unthinkable for the vast majority of amateurs; and that is regrettable, particularly when combining a mirrored diagonal with a refractor, thereby transforming the refractor into a catadioptric.

This erect-image diagonal has a 29mm aperture...

https://uk.telescope.com/Orion-125-Pentaprism-Diagonal/p/130876.uts

It's a five-sided prism, a pentaprism diagonal, and for correctly-oriented views.  In addition, there would be no Amici-line seen when viewing brighter objects; although you would very rarely encounter that, if at all.

Given its generous aperture, and per the observational agenda, that one would be best; for a correctly-oriented view.  It is only a 1.25", however.  For comet-hunting, I would use a 2" diagonal, and 2" oculars.

1 hour ago, AlanP_ said:

I am considering purchasing the HEQ5 mount without GoTo and upgrade at a later date. I am actually not sure how it all works though. What actually tracks the stars in sync with the earth rotation? Is it the mount itself that is motorized or is it the GoTo mod that does that? I ask because I am wanting to do DSO astrophotography. I am not too fussed about visual at the minute. I would love to take some deep sky images of Orion, Pleiades etc, which I could find easily without a GoTo mod. 

So basically, would using the mount without GoTo and a telescope attached allow me to do long exposures? 

 

Thanks

You can purchase the EQ-5, and upgrade that one with a go-to system in future.

A go-to system would make long-exposure photography far easier.  In the meantime, you could motorise just the RA-axis, for basic, automatic tracking, and "cut the teeth" with that at first.

7 hours ago, carastro said:

Yup that one.  No idea regarding series but the principal should be the same.

Carole 

Yes, that's the long-focus Newtonian, a true Newtonian, and the same 114mm f/8 OTA as I have within this Meade kit...

The OP's OTA however, whilst of the "PowerSeeker" series, is, as evident by now, quite different.

Incidentally, Meade did one better with that kit, as they included a sturdier EQ2-class mount.

51 minutes ago, Stormflagflying said:

Hi,

This is my first post to this group. I'm really looking forward to being part of this community as I take my first step into the stars ?
I was fortunate enough to receive a Celestron 130eq Telescope for Christmas (I have had to wait 57 year for my first Telescope but I now have one). The problem I have is that when I insert the 20mm erecting eyepiece and then look through it, the circle that you see (not sure of the correct name) is not full and looks like it is eclipsed at the top for about 40 percent of the circle. If I take it out of the Telescope and look through it I get a full circle and just to confuse matters even more if I insert the 10mm eyepiece into the Telescope then I do get a full circle to view the image on. So I'm not sure if the 20mm erecting lens is faulty?  I have raised the issue with Celestron Tech support but so far have had no response so I thought I would post here as I am keen to get out and get using it.
Appreciate you thoughts
Terry

Hello,

I'm afraid you won't get much use out of the 20mm.  The field-of-view will be quite narrow when compared to a 20mm Plossl.  Entry-level kits do not include the best of eyepieces and accessories, so you'll want to complement the experience with a Plossl or two, or three.  The included 10mm is most certainly usable, but it's not a Plossl, either.  Plossls are the barest minimum if you're wanting performance, and they're not expensive...

https://www.365astronomy.com/GSO-Super-Plossl-Eyepieces/

I would suggest a 32mm from that listing, and to help find your way around the sky.  That will serve as your lowest power(20x), for hunting, for observing the star-studded fields of the Milky Way, the Pleiades, and the galaxy in Andromeda. 

A 20mm Plossl will give you a power of 33x, and for closer look.  You can barlow the 20mm Plossl, for a simulated 10mm, with a 2x barlow...

https://www.365astronomy.com/GSO-2x-Barlow-2-Element-Achromatic-Barlow.html

...and for a power of 65x.  A 130mm aperture is capable of reaching even higher powers, however the manufacturer equipped that model with a spherical primary-mirror, instead of the accepted and expected parabolic.  A parabolic primary-mirror is the standard for f/5 Newtonians.  Why they chose to do that is somewhat unknown.  Therefore, it will be more difficult to reach, say, 150x, whilst at the same time enjoying sharp and pleasing views.   But you can certainly attempt 150x, and where the planets and other objects come into their own; for a closer look at the craters of the Moon, and for the splitting of double-stars.  The focal-length of a 130mm f/5 is rather short, at 650mm.  Let's see what it would take to reach 150x, when the time comes...

650mm ÷ 150x = roughly a 4mm eyepiece

In that event, you would need a 12mm Plossl and a 3x barlow, and for a simulated 4mm(163x)...

https://www.rothervalleyoptics.co.uk/antares-x3-achromat-fmc-barlow-lens-125.html

Or, if you already have a 2x barlow at the time, you can get either an 8mm or 9mm eyepiece.  With the 2x barlow and the 8mm, you would have a simulated 4mm(163x); with the 9mm, a simulated 4.5mm(144x).

Those are merely examples and suggestions.

Eyepieces are fully the other half of a telescope.  The two are one and inseparable.  You can't use one without the other, unless a camera takes the place of an eyepiece, as when imaging with a telescope.  The eyepieces and other accessories do not have to be acquired all at once, and they should be chosen carefully, as the eyes from individual to individual differ.  For example, if you wear prescription-eyeglasses, and find that you need to wear them at the eyepiece, then you may need eyepieces with longer eye-relief, and in order to see the full field-of-view.  Eye-relief is noted within the specs of the listings of most eyepieces; usually, 20mm of eye-relief is preferred by eyeglass-wearers.

Eyepieces, barlows and other accessories only have to be acquired once, as long as they're not lost or broken, and they can be used with any other telescope(s) that may be acquired in future.  I have over twelve telescopes, but only one of each focal-length of eyepiece, mostly.

You can motorise the RA-axis of the kit's mount, and with an economical 9V-battery(a lithium-type during the winter) motor-drive...

https://www.firstlightoptics.com/celestron-astromaster-series/motor-drive-celestron-astromaster-geq-93514.html

Such will allow you to track an object automatically, hands-free.  It will even cause an object to stand still there in the center of an eyepiece, and for as long as you'd like.

9 hours ago, anachristina said:

Hi! I am very new to SGL (just signed up a couple of mins earlier) and to astronomy as well, though I have been facinated with celestial bodies since I can remember.  I recently purchased a Celestron Powerseeker 127EQ but now I’m having troubles using it and I can’t seem to see anything through it. I also have a Celestron collimating eyepiece but I still can’t seem to make it work. Anyone here who has experience with the same scope? Would appreciate if we could chat a bit as I would be really interested in your experience and how you ultimately made it work!

Hello,

The Celestron "PowerSeeker" 127mm f/8 catadioptric is an economical alternative to a Celestron C5 or 5SE, a Schmidt-Cassegrain.  It's quite popular among the entry-level kits for that very reason.  I don't have one myself, not quite yet, but I will be getting one in future, and for an overhaul as I would want to get the best out it as well.

As with all reflectors, even the modified-Cassegrains(Schmidt and Maksutov), collimation, alignment of the optical system, is necessary, to be checked upon its arrival from the factory overseas, and occasionally thereafter as it's moved about and used.

The "PowerSeeker" 127mm sports a barlowing lens assembly at the end of the drawtube of the focusser, and may prove problematic when attempting to collimate the telescope...

http://www.whichtelescope.com/images/CatadioptricNewtonian2.gif

The telescope is not a conventional, traditional Newtonian, although "Newtonian" is at times included within vendor advertisements.  The telescope is, rather, a loose simulation of a rare design known as a Jones-Bird, which was developed in the U.S. back in the 1940s and '50s.  The lens assembly, as noted above, makes collimating the telescope a bit difficult for those first starting out.  It's not impossible, however.  If you intend to keep the kit, I would strongly suggest researching online the methods used to collimate one, and for sharp and pleasing images throughout its range of magnifications.  Use the phrase "Bird Jones collimation" when searching with your favourite web-browser.  There are also a few YouTube videos available on the subject.

Best of luck, and enjoy.

5 hours ago, carastro said:

I owned some years ago a similar scope but it was the 114 version.  I found the mount difficult to use but the optics great.

Are you by any chance trying to use the Barlow lens?  I could never see anything with the Barlow lens.  I would try initially using the lowest powered eye piece.  Point to something bright like the Moon and get it in focus.  Then if you want to increase the focus, replace the eye piece with a stronger one and re-focus.  But with this mount you will need to be quick as objects will pass out of the field of view (FOV) very quickly as the Earth rotates.  This is why the Barlow lens (doubling the magnification) makes it much more tricky.  

Once you have the Moon in focus you can move to other targets. 

HTH

Carole 

Did you own the "PowerSeeker" 114mm reflector kit, and of the same series as that of the OP, or the "AstroMaster" 114mm?

2 hours ago, thekwango said:

again, very informative and helpful so many thanks - however, i think the need to rotate the scope about (if i understand what has been said previously about EQ's) when moving/viewing different objects coupled with the fact i want to try and introduce my eldest girl might make the EQ's more 'awkward' (not the right word but i'm sure you know what i mean) 

if it was just going to be me wanting to look then i would jump all over the above but trying to keep a young 'un interested might just push the boundaries of her focus a tad?

In any event, I do hope you'll favour us with a first-light report upon receipt of the kit of your choosing in future.  Best of luck in your pursuit. 

2 hours ago, thekwango said:

thanks for another very informative reply. 

i think i'd best revert back to my original thoughts and look at the 127 Mak. i'm already more than doubling my original budget ( from £200 second hand to 450ish new) that mount alone is in excess of the revised budget! ? 

That EQ-5 with go-to would be for imaging, with a DSLR camera.  If for visual only, with eyepieces, you would need only a mount to get the telescope off the ground.

Let's approach the matter from a different perspective.  Let's concentrate on the mount, first.  You need only one mount, for visual, and for the taking of pictures eventually, whether with a DSLR or a webcam-type camera.  Within your first post, you were almost there by listing the 150mm f/5 Newtonian with an EQ-3 mount.  I feel that you were on the right track.  Consider...

https://www.firstlightoptics.com/skywatcher-mounts/skywatcher-eq5-deluxe.html

You can't beat that price for what it is, and for what it promises.  The mount is ideal, in its initial simplicity and wonderful versatility.  It's the next size up from an EQ-3.  It is also the "sweet spot" among all equatorial mounts.  It's not too small, nor too large; just right.  An EQ-5 will support telescopes from a wee 50mm f/12 achromat, to a 200mm f/10 Schmidt-Cassegrain, or a 200mm f/5 Newtonian even.  You did say "450ish new"...

https://www.firstlightoptics.com/reflectors/skywatcher-explorer-200p-eq5.html

...but I'm not suggesting that combination.  An EQ-5 does support that telescope, but for visual use primarily.

An EQ-5 would also support practically everything in between; one mount, and for a myriad of telescopes, for future-proofing.  In future, a go-to system is available as an add-on.  The tripod sports stainless-steel tubular legs, and superior to those of aluminum(like those of an EQ-3), for rigidity and stability.  With a lesser mount, as the magnification goes up, the shaking and wiggling of an image is magnified as well.  That won't do for taking pictures, not at all.  The human eye will tolerate such, if it must, but not a camera of any sort.  You'd never need another mount, really.  The next size up is an EQ-6, and it's an absolute beast to haul round.

A plasticky go-to mount, like the "AZ GOTO", is for the here and now, fleeting, expendable, like a day at the county fair, and very limited as to the telescopes it can support.  The same goes for the "Star Discovery".  On the other hand, an all-metal equatorial mount is for the decades ahead, and like one holiday dinner after another.

You could mount a 127mm Maksutov now, and a 130mm or 150mm Newtonian in future; all together, albeit one at a time.

The EQ-5 is like a canvas.  How would you "paint" it?

20 minutes ago, thekwango said:

 

i'm now toying with just going new........trying to search the second hand market when you don't really know what to avoid is a bit of a minefield and following a bit of a search of other threads on here i'm now leaning towards this combo. i had initally almost set my heart on the SW 127 Mak and goto but i've read the 130pds might be just slightly a better all rounder?

For visual, the 130P-DS can handle low power(20x), and up to 200x and beyond with the aid of 2x and 3x barlows; for observing the gamut, most everything in the sky.  For the higher powers, however, the collimation must be as near perfect as possible.  

Then there's its penchant for imaging...

https://stargazerslounge.com/topic/210593-imaging-with-the-130pds/

...although not quite to the level of an apochromat, in both image-quality and ease-of-use; but a formidable contender nonetheless.

For imaging, the 130P-DS should have at least this level of mounting...

https://www.firstlightoptics.com/skywatcher-mounts/skywatcher-eq5-pro-synscan-goto.html

Imaging would be possible to an extent with an EQ3-class mount, with basic tracking; no go-to.  But I'm of the mindset that if one is going to lug an EQ-3 round, they might as well an EQ-5 instead; for visual or imaging, or both.

The higher and highest of magnifications do require a mount with a basic motor-drive at least, or a computerised and motorised go-to; if more than one person is attending the show.  Among the varying apertures of Maksutov-Cassegrains, the 127mm hits the "sweet spot"; not too small, nor too large, just right.  Naturally, a Maksutov fitted on to a go-to mount is going to be more expensive.  In observing solo, a Maksutov on a manual mount would serve, and in roughing it.  A Maksutov simulates a long-focus refractor, like this one...

Now you can see why the Maksutov is so popular, as its tube is shorter, more compact.  The focal-length of a 127mm f/12 Maksutov is 1500mm, and the same as that refractor above.  What is done in the case of the Maksutov is that the long focal-length is folded, twice, and in three segments...

With both telescopes, that refractor and the Maksutov, low-power wide-field views are not possible.  A 32mm eyepiece generally provides the lowest power with a Maksutov...

1500mm ÷ 32mm = 47x

Let's see what the Moon looks like at that lowest power...

https://goo.gl/5LBHwR

By comparison, a 130mm f/5 Newtonian(with a 650mm focal-length) and that same 32mm eyepiece...

650mm ÷ 32mm = 20x, and almost binocular-like in power...

https://goo.gl/giHzzv

Quite a difference, eh?  With refractors and Newtonians, what you see is what you get: if the tube is short, a short focal-length; if the tube is long, a long focal-length.  Not so with the Schmidt- and Maksutov-Cassgrains.  Those short tubes are misleading.  Telescopes with long focal-lengths are not suited for seeing a large expanse of the sky at low powers.  Rather, they are for the medium, higher, and highest powers, and for observing objects up close, like the Moon, the planets, double-stars, and the smaller of deep-sky objects(which happens to be the vast majority of same). 

With a short focal-length, like that of a 130mm f/5 Newtonian, you can see a much larger portion of the sky, and if mounted on a manual mount it makes it all that much easier to find things in the sky; for hunting them down.  Once you spot an object of interest, you then ramp up the power to see it larger, more closely, and with the aid of 2x and 3x barlows...

https://www.firstlightoptics.com/reflectors/skywatcher-explorer-130p.html

The mount of that one can be motorised, no go-to however.  If you are to observe under heavily light-polluted skies, then go-to is generally recommended...

https://www.firstlightoptics.com/reflectors/skywatcher-explorer-130p-synscan-az-goto.html

...however, with that go-to kit, the telescope itself takes a "back seat" to the mount, in the telescope's construction.  The telescope within the first listing is better equipped.  In addition, with most any entry-level go-to mount, the telescope cannot be moved manually.  You have to rely on the motors and the computer to move and point it for you; sounds luxurious, no?  But if there's a battery, motor or computer problem, the telescope will be "dead in the water".  This go-to mount, however, can be operated manually in the event of electrical and electronic failures...

https://www.firstlightoptics.com/skywatcher-mounts/sky-watcher-star-discovery-wifi-az-goto-mount-tripod.html

But that's just the mount; no telescope included.  Although with that go-to mount, you can attach most any shorter telescope of your choosing...

https://www.firstlightoptics.com/maksutov/skywatcher-skymax-127-ota.html

https://www.firstlightoptics.com/reflectors/skywatcher-explorer-130p-ds-ota.html

Many go with a Maksutov due to the need for regular collimation(optical alignment) of a Newtonian; although a Maksutov can also require collimation, being that it's reflector too, but the need runs from nil to infrequent.  Of all the reflectors, a Schmidt-Cassrgrain is the easiest to collimate, followed by a Maksutov-Cassegrain, and with a Newtonian requiring the most attention to that aspect.  Refractors, on the other hand, require collimating the least, if ever; for example...

https://www.firstlightoptics.com/evostar/skywatcher-evostar-102-eq3-2.html

If you feel drawn towards a 130mm f/5 Newtonian, you might wish to consider a 150mm f/5 instead, and for that extra inch of aperture, especially if observing under light-polluted skies...

https://www.firstlightoptics.com/omni-xlt-series/celestron-omni-xlt-150.html

...or... https://www.firstlightoptics.com/reflectors/skywatcher-explorer-150p-ds-eq3-2-eq3-pro-goto.html

The Celestron has the better mount, with its tubular-steel legs specifically; the Sky-Watcher with the better Newtonian, and its two-speed focusser specifically.

When a Newtonian is mounted on to an equatorial, as shown within that listing, the tube, and the focusser, must be rotated every now and again for a more comfortable observing position, and during the equatorial's revolutions.  Such a kit is for observing a single object for a greater amount of time.  If you'd prefer to flit from one object to another in a span of a few minutes then an alt-azimuth is preferred...

https://www.firstlightoptics.com/reflectors/skywatcher-explorer-150p-az4-mount.html

...but motorised/computerised tracking is not possible with that kit.  With the 150mm f/5 Newtonian, low-power wide-field views are also possible. 

With the 102mm f/10 achromat(refractor) on its equatorial, the tube would not need to be rotated, therefore flitting about the sky is a good bit easier.  

There are also short achromats...

https://www.firstlightoptics.com/startravel/skywatcher-startravel-102t-ota.html

However, being short, and being an achromat, it would be suitable only for observing the dimmer objects of the sky.  If you point a short achromat at the brighter, bright and brightest objects, you will see colourful "rainbows" round and about them; false-colour, which blurs and smears the images.  The longer the achromat, the less false-colour seen when viewing brighter objects; but then you have that longer tube.  It's a choice between comfy and cozy ergonomics with the short achromat, or optical performance with the longer.

Inch per inch, or centimeter per centimeter of aperture, a refractor offers the sharpest and most contrasty images, and over all other designs.

And then, we haven't really begun to discuss eyepieces.  Eyepieces are fully one half of the experience.

Lastly, for the RA worm-assembly, I replaced the two plastic washers with those of sintered-bronze...

I then adjusted the position of the worm in relation to the gear.  Now, even with a telescope mounted, the one that came bundled with the mount...

...I can turn and twist the RA worm-shaft, without the slow-motion control in place mind you, effortlessly, and with a butter-like smoothness to boot.  The hyper-tuned EQ-2 mount-head, completed...

And now, for the "Twilight Zone" portion of the show...

There's something amiss here, and with the latitude-scale...

I pried the dial off, and re-glued it with epoxy.  It's now square and true, I think...

The DEC setting circle is fixed, and with screws, but look at where it points, and at its home-position...

...at about 85°.  You can't rotate the circle independently of the axis.  Is that correct, or does it even matter?  I know that I won't be using either circle, in a practical manner, but I want it to be correct nonetheless.

Now for the somewhat more difficult portion of the hyper-tuning, and of the RA-axis...

The needle-thrust bearing no longer has its thin-plastic washer to hold it place, in place within the shallow well, and so it drops down into the maw of the RA-gear...

I had to take the gear with me to my local hardware and cobble something or other together, and so I did.  I had a choice between a white-nylon or steel bushing, and chose the latter to fill most of the maw...

You don't want to have that bronze washer rising above the maw, hardly at all, so I had to sand it down a bit more after I took those photographs...

There, that's better.

There was a problem with the RA-spindle, or shaft, upon its arrival...

No, it isn't quite square and true, is it.  It turned out that its bed there at the bottom of the cavity had some irregular chunks of hardened glue or other.  The shaft was removed, its bed cleaned, and a sintered-bronze washer added, slipped over the shaft, and as the bearing surface for the tip of the flange of the RA-gear...

Incidentally, the DEC shaft is off a bit, too, although not as badly, but there's nothing that I have seen that could be causing it, other than poor workmanship; no surprise there.  I'll have to think about how to correct that in future, but fortunately it's not as crucial as that of the RA-axis which has been corrected. 

I'd rather have it a bit wonky there, than there.

Lastly, I replaced the RA-axis lock-nut with a new one, and added one sintered bronze washer and the original steel washer underneath it before battening it down...

I assure you, it's there, the bronze washer, but the steel washer obscures it, utterly.

I used only one of the thin-plastic washers, and for the RA-setting-circle; and in addition to a thicker, white nylon washer for the red-fibre, and here...

...and merely to keep the setting-circle from backing out of its cavity towards the RA-gear.  That thin-plastic washer was one of only two of the original parts that I retained.  The rest were replaced; the refuse...

...and with bronze, sintered(powdered) and solid(additions).  For the DEC lock-nut, the thin-plastic washer was cast aside, the red-fibre washer replaced with two of bronze compressed together with a vise, and with the inner diameter wallowed out a bit...

All of the sintered-bronze within this project was sanded smooth and polished with #0000 steel-wool and machine oil...

The Phillips-head screws of the lock-nut were also replaced, and with those of hex-sockets.

The lone red-fibre washer on up was also replaced...

The paint within the clamp-ring, and round the clamping-stud, was removed.  A 0.20mm-thick shim of phosphor-bronze was added, and for a snug, yet not tight, fitting of the two components...

I also did not want the clamping-screw to dig into the stud; better against the bronze instead, so I think.

Further up, and lastly, a 0.20mm-thick phosphor-bronze washer was fashioned and added above the clamp-ring, and where the ring contacts the rest of its slow-motion assembly and the mounting-saddle...

I simply cannot abide by painted bearing surfaces...

Look at how the paint stained that red-fibre washer, and the others as well.  The factory couldn't even wait for the paint to dry.  You've got to get this stuff out in a hurry, you know; pathetic.

Saturating the painted surfaces with 100% acetone, then scrubbing with steel wool, makes for a much safer alternative for gel-like paint-stripper.

Everything for the hyper-tuning was acquired locally, save for these, which arrived from California soon after ordering: needle-thrust bearings...

...28mm O.D. x 15mm I.D. x 2mm thick...

The RA and DEC shafts are 12mm in diameter; hence, a bit of slop...

...which was corrected with rods of brass formed into rings...

Not every last bit of slop was eliminated, but most, and good enough if not ideal as I didn't want any binding.

And now, for the hyper-tuning portion of the show; I won't say that I love one, but I am quite partial to an EQ-2, hence my driving desire to make the mount the best it can ever be...

The Bronze Age...

The Bronze Age is looked down upon, in relation to the Iron Age.  Once many everyday items were made of iron, steel, and stainless-steel, bronze took a back seat; but not in my household...

Those red-fibre and thin-plastic washers had no place within my mount.  Bronze is known to outlast the equipment, the machinery, into which it is placed. 

Basic tuning continued, and this time with the DEC-axis...

You first remove the lock-nut, which, again, also hosts the bar for the counterweight...

You can easily see the red-fibre and thin-plastic washers there, and the parts removed in that order.  But what's that at the top of the image?  Why, it's a shallow well, or depression, like something or other is supposed to fit there, but there's nothing there.  The RA-axis has one, too...

Hmm, the included washers simply cover those depressions.  Oh well, I have no idea for what they might be; as I do have quite a few blond hairs on me head, still.

After the lock-nut is removed, you simply pull the upper assembly up and out of the lower body...

...and there you see the lone red-fibre washer, and with no others.  The uppermost portion consists of the DEC slow-motion assembly, and the mounting-plate for the telescope.  You do not need to disassemble the slow-motion assembly.  You can simply clean off and away what factory-grease is accessible, then re-grease.  The DEC spindle, the shaft, should be cleaned as thoroughly as possible, in particular, and re-greased.  To make cleaning and re-greasing easier, the assembly can be taken apart quite easily.  You simply unscrew the spring-loaded tensioner, remove the black clamp-ring, and for easy access to all of the components...

Now, you don't have to take it apart, if you don't want.  I did, and it was rather enlightening in either the discovery or rediscovery as to how it functions.  Alas, however, there's no continuous, perpetual rotation possible with the slow-motion control; only with those of the EQ-3 and larger, I'm afraid.

Now for the basic tuning; the RA-axis...

Let's see what it looks like upon pulling it apart.  The lock-nut must be removed first...

Now to see what lies inside...

There's the RA-axis gear in all its glory, along with the setting-circle, and the basic red-fibre and thin-plastic washers.  The typical factory grease was found within, and of two types: a very-thick, whitish, glue-like substance, which served only to stiffen the fitting of the setting-circle within its cavity...

The other type was this yellowish, oil-like grease, which was the predominant lubrication throughout the mount-head...

All of the parts and surfaces were cleaned with what is used for outdoor grilling(steaks and what-not), which is a kerosene-type liquid.  It's called charcoal-lighter fluid here in the States, and it cuts through that factory-grease almost instantly.  Said cleaning-agent is rather evil-smelling, so use only with adequate ventilation.  After cleaning, all the parts and areas that required it were lubricated with Super Lube, a "Teflon" or PTFE-based lubricant, then the axis was reassembled.  But before reassembling the axis, there was room for immediate improvement, and of the setting-circle's fitting.  The fitting of the circle was not tight by any means, which is why that glue-like "grease" was applied; in effect gluing the circle in place, yet whilst allowing it to rotate, however it did its job most poorly.  Instead, I added the thicknesses of aluminum-foil tape(0.10mm), double-sided tape(0.07mm) on top of that, and PTFE(0.50mm) to the outside of the circle's flange...

...and for a dry and tighter fit within its cavity; no more rattling around loosely and unevenly.   I used strips of said materials, and combined were 0.678mm thick, and no wider than 13mm.  If these materials are unavailable, then quite possibly only a strip of self-adhesive felt may serve.  The cavity, of course, must be cleaned and degreased, and kept that way, as you don't want to muck up the felt, or the PTFE, therefore be careful not to apply new grease where contact occurs...

...like when re-greasing the shaft seen jutting upwards there.  Incidentally, the new lubricant needs to be applied only to the shaft and the very bottom of the cavity where the gear's flange makes contact with that bearing surface.

55 minutes ago, Kn4fty said:

That's a shame to hear. When it seemed Meade was pulling out of their funk a couple years ago, I bought an LX 70 R8. I loved it. Its been a great scope. Its been a real quality scope. I took that as a sign that Meade was finally out of their slump and putting out affordable quality products again. I'm sorry to hear that you got a rotten apple. Maybe Meade has slid down the hill again. I hope you get your mount working and Meade steps up.

Thanks.

As far as I know, there may be only two companies in China that manufacture these clones: Synta, and Ningbo Sunny(who owns Meade now).  However, it could be that only Synta makes them for all the brandings.  In any event, the factories are just down the industrial road from one another over there.  

Shop classes, at school; they've seemingly gone the way of the Dodo, here in the U.S. at least.  They were phased out at about the time I had entered high school, and with computers looming above the horizon; shame, that. 

The three main portions of the EQ-2 mount-head that may or may not require servicing...

For those who do not wish to take their EQ-2 apart, there are nonetheless three elementary points of adjustments that should be checked, adjusted if necessary, and in the hopes of freeing up these mounts, for smoother operation, particularly when using a motor-drive in order to prevent damage to same due to binding... 

1. The lock-nut of the RA-axis, located at the rear, or "butt"; it should not be too tight, nor too loose, just right rather...

I could not fit a socket-wrench within that cavity, so I used needle-nosed pliers.  As the nut is screwed in and out it remains in position once released; good thing that.

2. The DEC lock-nut is held in position by three set-screws round about.  Simply loosen the screws and rotate the nut; and again, into a position that's neither too loose, nor too tight...

The DEC lock-nut also hosts the bar for the counterweight...

3. The lock-nut and the adjustable-bearing for the RA worm-assembly...

The lock-nut is removed, the bearing screwed in and out, not too tight, nor too loose, and then the lock-nut is reinstalled to hold and lock the bearing in that position.  You should then be able to twist the worm-shaft with your fingers, freely, smoothly, and with no binding whatsoever.

If the worm does not mesh with the RA-gear just behind it, square and true, then these two bolts are used to adjust that...

It is the worm and the gear of the RA-axis that allows for tracking objects across the sky, day and night.  When the worm is motorised, it takes 24 hours for it to turn the gear, the RA-axis, once round.

I once had a Japanese-made EQ-2...

I ended up passing it on to a relative, and after I had acquired a Vixen GPD or GP-DX(EQ-5).  I haven't had either one since 2003-05; the former given away, and the latter destroyed in a fire.  In any event, the EQ-2 and EQ-5 are my only favourites among the series.

Here in the U.S., it is almost impossible to acquire an EQ-2 as a separate purchase, however they are readily available within kits, the most economical of these being the one I chose...

https://www.bhphotovideo.com/c/product/1061422-REG/meade_216004_polaris_114mm_german_equatorial.html?ap=y&gclid=CjwKCAjw2MTbBRASEiwAdYIpsdkrTeKGLoav4d7BipwU59Q5vvs09DfieIfZJlRKqKyFDr3DncRd_xoCn0YQAvD_BwE&smp=y

This kit, and many others come bundled with an EQ-2 mount, and are acquired by more than a few first starting out, worldwide.  They are Chinese clones of what was once, and all that that entails.  To wit, they do not necessarily arrive in working order; for example...

I could not rotate the declination-axis, and the setting-circle's pointer wasn't helping in being seemingly welded to the circle.  Others, no doubt, have received less-than-stellar examples of these mounts as well, again, worldwide. 

It's quite a pretty thing, yes, but pretty is as pretty does, and this one wasn't quite so pretty once I began to take it apart...

Of the current EQ series, the EQ-2 is the quintessential grab-and-go equatorial, in so far as an equatorial might be, and is capable of supporting a wide range of smaller telescopes that do not necessarily cause bouts and fits of aperture-fever.  Indeed, quite a few acquire one of these mounts after having fiddled and puttered round with those larger.