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Meade "Large Equatorial"(EQ-2) Hyper-tuning

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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...



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.  

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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.

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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.

Edited by Alan64

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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.


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.  

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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.

Edited by Alan64

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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.

Edited by Alan64

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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. 

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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.

Edited by Alan64

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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...




Edited by Alan64

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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.

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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.

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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...


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