A Restoration

[Alan64]

From the early 1970s until 2002 or so, the only mounts with which I was familiar was an AZ-1 and an EQ-2...

That's a span of almost 30 years, with a small alt-azimuth and a small equatorial.  But then, all I had were those two achromats, a 60mm, and an 80mm.

Then, I finally got a 4" refractor, which required a larger mount: a Vixen GP-DX...

Although two years after the mount's receipt, it was destroyed.  The astronomy-gods were most cruel in that.  However, I did manage to salvage the wooden legs, and have since restored them.

Ten years later, in 2013, I purchased a Celestron CG-4, an EQ3-class mount...

I got the 16" pier for it even, but then later halved it to 8.5" or so...

I tried to like the mount, but when you have to try to like something, in reality you despise it.  An EQ3-class mount is too large as a "grab 'n' go", and too small to support a wide range of telescopes, in aperture and physical length.  Then, in my case, I had had said Vixen, which supported my 4" refractor ideally.  The CG-4 couldn't even do that...

Then, yesterday, I received two boxes...

Edited June 19, 2021 by Alan64

[Alan64]

Manual equatorial mounts larger than an EQ3-class have all but vanished from the market here in the U.S.  Indeed, throughout the world even, it seems.  Across the way, in Europe, there is the Sky-Watcher EQ-5 and the Bresser EXOS 2, at least.  But here in the U.S., there's only one...

https://www.telescope.com/Orion-SkyView-Pro-Equatorial-Telescope-Mount/p/9829.uts

It is an EQ5-class, manual equatorial, and manufactured by Synta. 

I remember seeing manual EQ-6 mounts in the marketplace, but that was quite a long time ago.  Perhaps I should've gotten one when I had the chance.

I know why they're going the way of the Dodo: light pollution, astrophotography, "Dobsonians" and the popularity of other types of alt-azimuth mounts.

Vixen; all Vixen offers these days are manual, EQ3-class equatorials.  At least they're made in Japan.

The last manual, EQ5-class equatorial, other than Orion's, sold here in the U.S. was the Meade LX70.  It is identical to, exactly the same as, the Sky-Watcher EQ-5, but with Meade-blue accents and a cheap sticker or two.  Over a year ago, I was seeing them being sold for only US$199, then they were discontinued, never to be seen or sold again.  Just this month, June still, Orion bought out Meade.  I don't really know what to expect as a result.  I'm not a big Meade fan, but I do have a few items bearing the marque.

A week ago, I ran across this...

...and offered by my old friend, Bill Vorce, of Telescope Warehouse in Arizona, a Meade liquidator.  Mr. Vorce had already sold four of them before that second listing.  I hesitated a full day, and because it doesn't come with a tripod.  Then it dawned upon me: the tripod of the Celestron CG-4 is the exact same one that came with the Meade LX70 before they were discontinued.  I then bought the first one of that second listing.  When I woke up the following day, the other three vanished, sold; incredible.

[Alan64]

All of the parts were accounted for...

 

My old Celestron CG-4 and my new Meade LX70 compared...

What a difference.

A tower it is, a tower to the stars.

My 4" refractor, once again, has a suitable roost.

Now, I can't use this mount until I take it completely apart and go through it with a fine-toothed comb.  I will use this to motorise the RA-axis...

I would like a single-axis drive with a hand-controller, for the RA-axis only, but I would have to order it from Europe.  I may, in future.

Upon its arrival, both axes were and still are stiff as boards.  When I get done with it, it will be as a well-oiled gyroscope.  In addition, the CG-4 will be cannibalised for the sake of the LX70: the smaller, lighter counterweights, the adjustment-bolts for the latitude-scale, and whatever else I deem fit.

I don't think that this Vixen "Great Polaris" clone is the equivalent of my old GP-DX, but of a GP at least.

[Alan64]

This will be of some help... http://www.astronomyboy.com/cg5/

The clutch assemblies, for the axes...

See those two black, plastic buttons?  They will be replaced with those of brass.

The latitude adjustment-bolts of the CG-4 and the LX70...

Those of the CG-4 appear more traditional, old-school, therefore those will be used with the LX70.

Once I get this mount-head torn asunder, I might re-paint it; that is, I'd love to.

 

[Alan64]

From this point on, the renovation of this mount-head will take place.

Have you ever wondered what your Sky-Watcher EQ-5 looks like on the inside?  Eventually, you'll wonder no more.

The RA-axis and the DEC-axis will be serviced.  But first, the latitude-axis components were removed.  Said axis, too, is stiff as a board.  The adjustment-bolts will move it, but it shouldn't be that tight.

To remove the latitude-axis plastic caps, I used a small flat-bladed screwdriver and a small hammer, and popped them off, both sides...

That's not a lock-nut, but just a regular nut.  I will be getting a lock-nut for it in time.  After removing the nut, the bolt seemed to need unscrewing too, but not really as the hole is not threaded...

It was, no doubt, the paint trying to hold it in.  The setting-circle assembly on the backside of the RA-axis, at left, was unscrewed and removed.  A polar-scope will be inserted later.

It's off... 

Note the four clear-plastic washers, two for each side.  I may replace those with nylon washers, if possible.  I don't feel that bronze is needed there, but who knows, I just might.

[dweller25]

Great thread 👍

[Alan64]

Next, I removed this plastic cover for the RA-worm assembly.  It's awfully large for just that...

To make it easier to work on the axes, it's best to separate the two, which is very easy to do, and in using a 5mm hex-key...

There were no washers to be found in that instance; just a simple bolting-on.

Now that the two axes are separated, that will make it much easier to work on each.  But before beginning, a tool needs to be made...

That's two galvanised 4d nails into a piece of oak, and spaced 1-5/8", or 41mm, apart.  I pre-driiled the holes for the nails with my small drill-press, and to ensure that the nails are driven in straight and true.  I used a drill-bit somewhat smaller in diameter than the nails themselves, and for a tight fit.

Edited June 22, 2021 by Alan64

[Alan64]

The aluminum RA-axis nut...

That's what holds the RA-axis together, and must be removed to access the components within the axis.  Note the two small holes of the nut, which correspond with the tool that I made.  But before the nut can be unscrewed, there are three set-screws to loosen, and with a 1.5mm hex-key...

Those three set-screws prevent the nut from unscrewing, therefore they must be backed off before attempting to use the home-made tool.  Each set-screw is accessed through this hole...

The axis is rotated to access all three, one at a time.  After that was done, I removed the nut.  I'm happy to report that cyanoacrylate adhesive was not used by the factory to "secure" the nut.  With my CG-4(EQ-3), however, "super glue" was used...

With the set-screws backed off, it was then safe to use the home-made tool to unscrew and remove the nut.  After removal, I was presented with this...

Then, when I removed that, I happily beheld a ring of ball-bearings...

After seeing the ring of ball-bearings, I covered the ring, and screwed the RA-nut back on, to keep the axis together, but I didn't re-secure the nut with the set-screws.

Edited June 22, 2021 by Alan64

[Alan64]

The anatomies; the RA-worm was removed...

I haven't taken it apart yet.  I will need to find or make a tool for its nut as well.

The RA-axis, exploded...

The two large plastic washers, which will be replaced with those of phosphor-bronze(510), are 0.020"/0.51mm thick.  However, the bronze sheet will be only 0.008"/0.20mm thick.  The total discrepancy, the loss, will be only 0.024"/0.61mm, and of no consequence...

Why, I'm suspecting that the worm will mate with the gear more accurately as a result.  In any event, this is not an ultra-precision mount-head.

The rear ball-bearing assembly, with its two covers...

The forward ball-bearing assembly; a sealed, radial ball-bearing...

It's a JESA W2, 6007 RZ...

JESA is a Swiss company, with factories in Switzerland(of course), and China; manufactured in the latter, no doubt.

The bearing is well set into the housing.  I will not be removing it.

I was pleased to discover not a single glob of the proverbial glue-grease within the RA-axis.  The grease used was quite like, dare I say, Super Lube.  In addition, and most importantly, I did not find any real need to de-burr or polish any bearing surfaces within the axis.

I have two 6" x 12" sheets of the bronze ordered.  With the USPS's performance of late, I might receive it in a year, if I'm lucky.

I had gone out yesterday and got a 10mm lock-nut for the latitude-axis, along with two thinner washers to compensate for the increased thickness.

I also got a rattle-can of gloss-orange paint, but not for the mount-head per se.

Edited June 23, 2021 by Alan64

[Alan64]

The DEC-axis' saddle-head and worm were removed...

It was quite the journey in reaching the DEC-nut...

Unlike the RA-axis, the DEC-axis is full of glue-grease.  Yucks!

The DEC-nut has only two set-screws to loosen and back off.  However, I had to make another tool to unscrew it...

The DEC-axis, exploded...

Its two large washers are the same thickness as those of the RA-axis.  It appears that the worm-gears of both axes are the same.  All of the DEC-axis washers will be replaced with those of bronze as well; or, needle-thrust bearings.  I'll have to research the latter to see if it's possible.

I may have to do some polishing of the surfaces within this axis.

I haven't cleaned the factory-grease out of either axis yet, at the time of this posting.

 

[Alan64]

The components of the DEC-axis have been de-greased and carefully set aside...

At present, the components of the RA-axis are being de-greased...

I got that 64-ounce jug of charcoal-lighter fluid just the other day.  It breezes through all types of telescopic grease, melting it all away like hot butter.  It's cheaper than paint-thinner, let alone more-costly mineral-spirits. 

[Alan64]

The RA-axis is de-greased...

I still haven't touched the worms, but there's no hurry.

[dweller25]

Marvellous 👍

[Alan64]

I finally got everything ordered to enhance the mount-head.  I ordered two 6" x 12" sheets of 0.008" phosphor-bronze(510), two 5" x 7" sheets of 0.006" phosphor-bronze(sometimes you need a somewhat thinner piece for something or other), two 3" x 6" sheets of 18-gauge(0.040") aluminum(for the latitude-axis), and one of these for the DEC axis...

https://www.vxb.com/AXK3047-Thrust-Needle-Roller-Bearing-p/kit8683.htm

Edited June 24, 2021 by Alan64

[Alan64]

Now that I think about it, it is rather barbaric in enclosing steel within steel, and then bearing and rubbing the assemblage against aluminum...

Those shrouds enclosing the ball-bearings are only barely magnetic, like some stainless-steels, but they don't gleam like stainless.  But in that they're magnetic nonetheless, that means that they contain iron, and you don't want iron rubbing against aluminum.  You want something relatively soft between them, as a buffer, like plastic as it comes from the factory, or copper and its alloys; bronze in this instance. 

There is aluminum-bronze, but it is said to be nigh as hard as steel.  Then, there is silicon-bronze, which sounds most interesting, but both of those types are sold on websites with "Request a Quote" buttons, and all that that entails.  There is also zinc-"bronze"(220), which is actually closer to brass; for jewellry and other arts & crafts.  You don't really want to use that, as it might deform over time.  

This mount-head is practically all aluminum, even the RA and DEC pipes...

Yea, this is, after all, a pipe-mount.  Incidentally, the pipes of the CG-4/EQ-3 are of steel...

In any event, you can't get away from the pipes, I'm afraid, with these.

In other news, have a look at this...

I suppose, there in the factory overseas, they bumped heads together one day...

"They won't notice.  You can't see it from the top."

There's nothing to retain that washer.  It oscillates, albeit very slowly.  The enclosure and pipe will keep the washer from coming completely out, but really. 

That will be getting a full-span, bronze washer, from the outside edge of the worm-gear to the outside edge of the pipe...

[Alan64]

I found my last bit of 0.008" phosphor-bronze sheet...

As I marched towards where the worm-gear was being kept, I thought, "It probably won't be large enough"...

Quite enough, and with a bit to spare, but not for any other washers; although one, but only one, for the needle-thrust bearing perhaps.

[callisto]

Loving your updates 

 

Mark

[Alan64]

To make the bronze washers accurately, I got out my old compass.  I've had it for quite a few years...

It's nothing special, at all.  Then, I got to looking round online and spotted this one at my local, discount, Chinese-hardware store...

It's of carbon-steel, readily locks into position, unlike the other, and the tip of one leg at least is noted on the packaging as being a scriber in its own right...

Ouch!

That's the 6" version.  They also carry a 12".

Edited June 25, 2021 by Alan64

[Alan64]

I made the main RA-washer out of that last section of an old sheet...

The center-hole however, which fits over the RA-pipe, is not as snug as I would like, with this much of a discrepancy...

That's with the washer shoved over all the way to one side, therefore the washer would oscillate in so far as that gap would allow.

Then, the gap being about half the width of the innermost ring of the sealed bearing...

...which is the only part of the bearing that rotates.

The washer is at least "good enough", perhaps enough even for so-called "government work".

I got these pin-less scroll-saw blades, jewellers' blades for metalwork, in 2014, along with other blades for woodworking...

...in addition to the adaptor set which enables me to use pin-less blades with my scroll-saw.  Said blades have very fine teeth...

...and breeze through the bronze sheet almost like butter, but not quite.  I do have to make certain to hold the sheet down firmly whilst sawing, and to keep same from riding upward.  The blades do make it quite easy to create these washers.

Once I receive the new sheets, I will then decide if I want to re-make the washer.  After all, it is the main washer, and the largest, within the head.  

[Alan64]

I took the lemon...

...and made lemonade.  Almost there...

<grind, grind, grind, polish>

That now being the RA secondary-washer.  I will be making another RA primary-washer once the new sheets of bronze arrive.

I endeavoured to make the secondary as snug as possible, as the bearing surface at the bottom of the well is quite narrow...

If only it was wider, I'd feel better about it.

[F15Rules]

What a fascinating thread!👍

As it's progressed, I have become more and more cognisant of my complete ignorance of engineering, but more and more admiring of  astro colleagues like you, who can, and do, attempt successfully this kind of work.

It looks as if when you're finished, Alan, you will have a mount head that will be the engineering equal (or even better?) of your late, lamented Vixen GP-DX - a properly engineered Japanese mount, built in the good old days to a "standard", not to a "cost".

Thanks for all your effort in sharing this project: I'm sure it will inspire some of our more technically able members to take on such projects..as for me, I'm content just to watch and enjoy this fascinating journey!👍

Dave

[Alan64]

The 30x47x2(mm) needle-thrust bearing, from VXB Bearings in California, arrived this late morning, and for the DEC-axis.  It fits snugly, like a charm, over the DEC pipe, yet spins freely...

That's the result of the 30mm I.D. 

However, I took a gamble, a risk, in getting this bearing with its 47mm O.D.  I would've preferred a 40mm, but that was not written in the stars to be.

It almost falls in where it's supposed to fit, but it will snap in, and is easily popped back out...

The inner wall of the cavity is perhaps 46mm in diameter, at least.  There's a wee bit of over-spray, paint, there within, but after I sand that smooth, perhaps grind just a bit round the bearing itself, it should then fall in place and spin freely.

The bearing will be sandwiched bewixt two bronze washers, lovingly crafted by yours truly.  Can't have steel bearing against aluminum in both directions, gracious no. 

Admittedly, this bearing may only amount to fluff, and nothing more, but I wanted at least one within this axis.

[Alan64]

Alas, I can't place a bearing on the other side, down into the rabbit's hole...

...but a bronze washer will be added there instead.  Whether or not the bearing-surface or its mate will bear against the washer is anybody's guess, but I can't take the chance without one.

[Greymouser]

17 hours ago, Alan64 said:

The 30x47x2(mm) needle-thrust bearing, from VXB Bearings in California, arrived this late morning, and for the DEC-axis.  It fits snugly, like a charm, over the DEC pipe, yet spins freely...

That's the result of the 30mm I.D. 

However, I took a gamble, a risk, in getting this bearing with its 47mm O.D.  I would've preferred a 40mm, but that was not written in the stars to be.

It almost falls in where it's supposed to fit, but it will snap in, and is easily popped back out...

The inner wall of the cavity is perhaps 46mm in diameter, at least.  There's a wee bit of over-spray, paint, there within, but after I sand that smooth, perhaps grind just a bit round the bearing itself, it should then fall in place and spin freely.

The bearing will be sandwiched bewixt two bronze washers, lovingly crafted by yours truly.  Can't have steel bearing against aluminum in both directions, gracious no. 

Admittedly, this bearing may only amount to fluff, and nothing more, but I wanted at least one within this axis.

You show an awful lot of skill in what you do, post some wonderful fascinating stuff. I wonder though, with your skill, have you ever thought of building your own mount from scratch? That would be truly fascinating.  

[Alan64]

Just now, Greymouser said:

You show an awful lot of skill in what you do, post some wonderful fascinating stuff. I wonder though, with your skill, have you ever thought of building your own mount from scratch? That would be truly fascinating.  

Thank you.  I suppose, if I sat my mind down to it, I might manage an alt-azimuth; but heavens no, not an equatorial.  I do manage to improve on what the manufacturers overseas produce.  But I do have to have the initial precision afforded by their equipment.