"Ideal Mount for Day Use or Casual Astronomy -- This mount is quickly becoming my favorite for use with this scope as it is light weight, stable and is very easy to move around my yard in order to avoid trees and other obstacles."

In another article, which started all the trouble here on Full-Moon Essays, I lambasted the various el-cheapo rechargeable battery systems that are proffered for use with GOTO scopes and laptops. The problem I immediately had with all the ones I tried was that they were simply gutless: ran down before I could get far into any observing session. Yet, strangely I found that similar batteries were being promoted by satisfied users on the newsgroup sci.astro.amateur: a perfect example of what I might call "trying to extrapolate apples from oranges." Portable battery works for astronomer X; ergo, it will work for ME, astronomer Y! Well, 'fraid not.

I was stung yet again when I read through some reviews of various alt-azimuth mounts. There is one big, fancy, somewhat pretentious site that shall remain nameless, offering any old user the opportunity to drop in and leave an ASCII-dump...err, a review. Though the commentaries are generally much better organized and composed -- even sometimes illustrated with nice pictures -- than posts to the amateur astronomers' newsgroup, once again, "you get what you pay for": free reviews are CHEAP reviews that are hard to correlate with your own reality.

The reviewers often start out with "This was my first [telescope - mount - camera - starchart program - binocular; you name it]" and those are the ones to watch out for! Why would somebody who has used telescopes for thirty years be the slightest bit interested in the remarks of a person -- well meaning though he or she may be -- who has just graduated to a new SCT from a 60mm dimestore scope? What gems of wisdom, experience, or insight could they offer to the community, aside from perhaps exposing a product that doesn't work at all out of the box (which occurs all too frequently with expensive astro toys purchased mail-order.)

At the other end of the spectrum, the site contains reviews of rubidium alloy quadropochramat 80 mm refractors with motorized focusers, gravity-wave powered dewshields, and titanium mounting rings, costing 115,000 Saudi Arabian Riyals. If your desert oil-field has just brought in another gusher, you can pick up a few for your tribe to keep track of the falcons.

That leaves the odd reader stuck in the cracks, having champagne tastes but a ginger ale pocketbook, along with the incessant desire for as much quality as possible -- always at a discount price.

I made the mistake of reading a rave review for an inexpensive alt-azimuth mount, in that delicate psychological moment when I was wondering what I would ever do with an "impulse purchase": an 80 mm f/5 achromat with decent, sharp optics that seemed too cheap to pass up when I was idling away a Sunday afternoon at the "friendly local telescope store" (we do have but ONE here in the silicon valley. I'd tell you that name, but after the remarks I'm prepared to deliver below, I still have to show my face there, because I've purchased all my new scopes from them. Let's just say that they're named after a constellation. Sure, the store is called Poniatowski's Bull Telescope Center, just down the road from Apple Computer headquarters...is that vague enough?)

Several people reviewed this contraption. All liked it, one claiming that it was now his favorite mount for grab-n-go astronomical viewing: he was really enthusiastic about it, exulting, "I now have a near-perfect casual setup with a lightweight but rock-solid tripod with the all-important slow-motion controls, and a great little scope - excellent !" Another owner compared it favorably to a much more expensive Japanese mount of similar design: "Basically, everything good said about the Vixen Custom mount ... applies equally... And it is cheap." Another commentator, who sounded convincing and experienced, claimed, "Tracking objects with the mount isn’t too bad – it has slow motion controls on each axis that facilitate this...simple, uncomplicated, quick and easy to set up... a good combination for terrestrial and astronomical use."
Well, gentle reader: are YOU convinced yet?

After thinking about it for a few days, I realized that the 80 mm scope would be absolutely useless on my lightweight camera tripod, with sluggish pan head. So I stuffed $150 plus tax into my wallet, dropped in to "scope row", and exchanged valuable US currency for a heavy, bulky Chinese cardboard box. Problem solved!

However, bad weather intervened, and by the time I was setting up to do some astronomy with my larger scope, bringing the wide field refractor along to view large diameter objects at low power that are not appropriately framed in the narrow field C-11, a month had passed: and I was now in the dreaded "past return warranty" territory that would stretch on forever until the end of the universe (be it flat, expanding, or contracting: no matter. I could NOT return it now!) Murphy's Law did not disappoint: the moment I tried out the contraption, I realized that something was definitely amiss; my expectations were seriously unrewarded.

There was no way to balance the mount. There was no clutch on the altitude axis, and no hand tension-adjuster: merely a gigantic nut that would require a gargantuan wrench. Turning it one degree counterclockwise would cause the altitude bearing to FLOP down toward the ground. To prevent this, you crank it two degrees clockwise and = PRESTO! = it's so tight you can't move the scope up or down. Bah!

You could move the scope up and down by a small amount, using the slow motion control. But if you wanted to repoint by more than a couple of degrees, you could only do this by grabbing the scope with both hands and pushing it hard, against the friction of the altitude bearing. At the very least, the mount should have been equipped with a handle to increase leverage. Without it, adjusting the altitude was an extremely crude process, and even risked tearing the scope loose from its mooring!

The worst design flaw was the position of the altitude bearing right at the center of the tripod top, not allowing the telescope to point up higher than about 60 degrees. Wait -- what about "a good combination for terrestrial and astronomical use"? I later looked back at some of the reviews. One fellow gave this caveat: "I found a blind spot near the zenith where the OTA itself would meet a tripod leg. This is again easily solved [my emphasis] by rotating the mount/tripod so that the OTA slips between two legs at the zenith. I can live with that, and am always careful to ensure that the tripod legs are positioned ‘just so’ right at the start of the viewing session."

Could I make this accomodation? To do it, first I'd need some mounting rings, which cost me nearly $20: not bad, considering the expense of rings for some of the premium quality small refractors, especially those made by one "Uncle Al." Did this help me balance the scope away from the center of the azimuth bearing? Why, NO! (But it did lighten my wallet, the only practical result of my experiment.) There was simply no way, even by slipping the telescope as far as possible inside the rings, to enable me to point higher than about 75 degrees. And, you could not sweep smoothly in azimuth because you'd encounter the leg, move the rear of the scope up, over, and down again and try to get your field of view: a complete bother. Useless for astronomy, unless you liked to look only at objects near the horizon, where heavy air dimmed them and made them shimmer. WHAT WERE THESE PEOPLE THINKING? This mount, I muttered, is a DISASTER for astronomy, casual or otherwise.

Frankly, I was embarrassed about the whole thing. I couldn't return it; couldn't use it. I have no need to use it as a terrestrial spotter; indeed, the mount is far too clumsy and massive for that purpose. I dismantled it, shoved the parts back in the box, hid it in the corner of the garage, and tried to forget about it (grumbling all the while about the nice Furtwängler CDs I could have purchased with the same money.)

Months went by, and I kept shoving the big Chinese cardboard box back into its garage corner, where it kept peeking out (intentionally, no doubt, so that I would continue to be reminded of my humiliation.) Finally, I could stand it no more. I drove the car out of the garage, and laid out all the parts on the concrete. What to do?

In short order, I'd contrived the idea of a Rube Goldbergesque contraption: a modification of the scope mounting plate to turn it UP so that it rose away from the horizon, with a 25 degree tilt insuring that I could just about hit the zenith and avoid much contact with the tripod legs, if any.

To balance the scope, reducing the need for sheer torque on the azimuth locking nut, I fashioned an exceedingly crude counterweight from a bent aluminum bracket and some heavy metal spacers. As you can verify from my handiwork at left, I do not have a do-it-yourselfer's paradise of a workshop: no sirree! Just a few old tools left over from my dim, distant career as a radio transmitter repairman: hammers, sledge hammer, crowbar, more hammers -- ball peen and otherwise -- and a bludgeon or two: all collected for making necessary delicate adjustments. I bent, smashed, and knocked the parts into a semblance of the necessary shape, reassembled the mount, and tried it out, not expecting too much success at First Light.

My judgment: a 2% improvement. But, the sheer embarrassment of having anybody see this, including my wife, outweighed the benefit.

I phoned O...err, Poniatowski's Bull Telescope Center, and asked the manager if their "table top equatorial mount" could be used without its little spindly legs, mounted instead on the existing tripod from my now-ridiculous alt-azimuth mount. He looked it over and delivered the verdict: "Probably not." BACK into the cardboard box...

Time to cast a jaundiced, world-weary, and skeptical eye again on the Internet; re-read the reviews; and look for suggestions. My first discovery was that a somewhat more handy soul had independently trod the same territory, creating his own series of modifications that were intended to correct the same perceived flaws: see Antony McEwan's article. It looks good; but the fellow had a spare commercial rod and counterweight, which I had lacked. That made balancing much easier and created a more finished, less silly, appearance. I went inside and rifled through my wife's sewing drawer, and could find no such contrivance here in Casa Roper; my mod was doomed to look as terrible as I felt about it.

I also discovered that the fellow who bragged that this cheap knock-off mount was just as good as the more expensive Vixen mount must be two elements short of a Plössl: see how the Japanese engineers had taken the effort to include the all-important counterweight by reading this review by Ric Capucho (who, by the by, notes that even the Vixen version is seriously deficient, having the same flawed altitude clamping system.) As I looked further and further, I could see that my initial web search had been inadequate: I'd missed the coverage of all these details.

And, I'd tragically missed finding this: a quite affordable, elegant alt-az mounting head by Borg, distributed by Hutech (the company that makes the fancy filters used by many advanced astro-imagers.) The head assembly has what appears to be a PERFECT design (if it could be adapted to my 80mm tube assembly): the scope swings above the center of the tripod, and the slow-motion controls aren't the big shaky danglosities that wiggle the whole assembly back and forth in the Chinese adaptation that I was stuck with.

But, I'm getting ahead of myself and telling the story backward, like Dr. Watson sometimes did to Holmes' dismay. For, I found the Borg tripod head after I had already crafted a sort of solution, a much cheaper one though a clumsier contrivance.

A trip to Cuper...err, the community where the scope store resides (which I won't name) yielded an opportunity to examine the inexpensive table top equatorial mounting head for myself. Certainly the center mounting post was NOT the same dimension as the central hole on top of the tripod for the alt-az mount; but some hardware could surely fasten the two objects together without requiring machining, drilling, or filing. I purchased -- lightening my wallet by the factor of half a hundred dollar bill -- the table mount, and dismantled the bottom, putting aside the outer ring and little shaky chrome plated spindles that pass for "legs". Then, I took the equatorial head assembly into my best local hardware store and found a long metric threaded bolt that would fit, and obtained some large collar washers. The picture at right above shows where the bolt and washer were fitted through the shaft hole, with the original alt-az head removed.

I carefully aligned the Equatorial head evenly on the top of the tripod, and then tightened the central mounting bolt with a socket wrench. Voila! (How many times have you read this on a website, and found that the writer had spelled it "viola"? This is, I presume, an exclamation by a symphonic conductor toward the right hand stand of large fiddles...)

Now, I had a pretty sturdy equatorial mount, which very easily points right straight up at the zenith: making it no problem at all to sweep the scope around the highest objects, where they are brightest and clearest in the sky (benefiting, too from a darker sky background: everything you can do to help the image using a small aperture scope is very important!) The equatorial mount had much smoother operating slow motion controls, too. But, there were still significant problems: scope and mount balance, and mount shakiness due to a heavier mass on top.

I remembered the advice of my friend astrophotographer Charles Chew, modifier extraordinaire, who has tweaked every optical gadget he's ever owned in the goal of optimizing it for his needs and taste: he too had one of those small tripods, purchased years ago for his Celestron C-90; but it was too shaky. So he filled the legs with sand!

Out to the wife's potting shed I trudged, and digging underneath her bench I found a 50-pound bag of sand, only slightly depleted. I tore open the bottom and top plastic fixtures in each hollow aluminum tripod leg, and poured in sand through a funnel until each one was filled to the brim. To keep from losing sand, I stuffed in crumpled up sheets of aluminum foil and tamped them down until things were solid and tightly sealed. Only a grain or two of sand fell from each leg when I shook them all rather violently: success! And, they were HEAVY! I bolted the tripod back together again, now fairly struggling to carry it back to the garage. When the tripod top was re-bolted, and all fastenings tightened thoroughly, the entire assembly was remarkably firmer. I felt pride -- well, not pride exactly, but let's say NOT AS HUMILIATED AND SILLY as when I had tried to modify the alt-az head with my crude counterweight!

The central accessory tray was a thorn in my side. It originally mounted to the top of a contraption that had to be completely removed to collapse the tripod; furthermore, it added virtually no stability to the leg assembly. I modified it so that three short metal brackets could remain attached to each leg, and then screwed individually to the tray through holes I drilled. Wing nuts were used to fasten the screws, more convenient than tiny, easy-to-lose nuts. This stabilizer now acted as a proper leg-spreader and increased the firmness of the entire mounting assembly.

And, as you can see above, I marked each tripod leg with 1-inch increments so that it would be quicker and easier to adjust their heights, now being able to tell exactly how far I was sliding each one.

The final task was to enable complete static balancing of the telescope tube assembly, which I accomplished by making a counterweight system from an aluminum bracket, nuts, bolts, and washers. The result: even without the RA and Dec axes being clamped, I could position the telescope in any direction, let go, and have it stay in position.

Now, I know that some of you will be snorting to yourselves, "Waldee: WHY didn't you merely buy the equatorial mount in the first place?" You might as well ask "Why haven't you any sense and foresight?" for I did what I did, stupidly, by paying attention to REVIEWS -- reviews that were written by people without my sensibilities, needs, and goals. People who, for instance, did not think it was a problem that their telescope could not be pointed higher than the angle of the salute given by Kim Jong Il's goose-steppers. People who haven't a clue about astronomical observing, but who are anxious to write reviews!

In my defense, it cost less than scrapping the useless alt-az mount and buying the equivalent-sized equatorial; and the result is FAR beefier than the cheap bargain-basement equatorial head and tripod available for about a C-note from the same dealer. The addition of the sand and center tray stabilizing really improved the solidity. So, as a learning experience, I'm chastened but satisfied.

However, the equatorial head is, as you'd expect, a bit hard-pressed by the 80mm refractor tube assembly AND the counterweight. It's not practical to use my heavy Stratus eyepiece with this telescope setup, though it's fine with my regular lighter weight 1.25" oculars. Nothing bulkier than this short rich-field type tube could possibly be used with this equatorial head. And, the setting circles are not the slightest bit practical for locating objects.

Would I do all this over again? NOT ON YOUR LIFE! This was a patch-up, a make-good, a kludge (to use the old engineering term.) I would definitely consider, instead, a decent alt-az system with fine-motion controls, such as this Borg model, or this Vixen: I would only have spent a bit more than twice as much, but would have had a functioning gadget -- right out of the bulky [Chinese] cardboard box.

Furthermore, even with the customization, the cheap conventional mount makes the whole telescope look a little like a slightly bulked-up dimestore machine, so I won't be taking it to star parties and setting it up next to Takahashi astrographs.

Moral: DON'T TRUST or BELIEVE AMATEUR- AUTHORED TELESCOPE REVIEWS... including mine. Be a skeptic, and verify all claims: especially before spending any money - srw

Update, 10/12/07: I have just created an alternative pipe mount alt-azimuth system, which is suitable for a small reflector or refractor telescope, and usable if you have a heavy tripod (such as the one I acquired with my Celestron C-11 telescope.) It is simple, inexpensive, and easy to build: read about it here.

Update, Feb. '08: My further use of the modified mount, using the "table top tripod" equatorial head (which is exactly equivalent to what is known as an EQ-1 model), has been somewhat frustrating. In equatorial mode, with the ST80 refractor and the heavy counterweight, the mount worked fairly well, as the weight on the polar axis kept it from shaking too much. But when I tried to use the mount in alt-azimuth mode, with the polar axis rotated up, I found that there was far too much play in the bearing. The picture above shows my attempt to improve the functionality of my "StarBlast" 4.5 inch reflector scope for convenient alt-az sweeping. The poor fit of the polar axis -- which has a play of about an 1/8th inch (!) -- caused instability, and difficulty in focusing and positioning. I dismantled the EQ-1 head and found the problem: the machined tolerances are simply too poorly fitted, with unacceptable slop as the result. And the axis clamps are ineffectual. Finally, the metal used is too soft. There isn't a single thing "right" about the design of this mount (especially the tiny diameter of the polar axis shaft, which is far too small even for a light telescope tube like the ST80.)

I tried replacing the deficient polar axis shaft with a heavy threaded rod, loaded by a strong spring (shown in the snapshot above); it yielded a slight improvement in stability, but the entire system "rang like a bell" and took more than three seconds to stop vibrating: worse than using the StarBlast on its original wooden base.

Having decided that, long-term, I'd prefer not to use the ST80 by itself but rather as a piggyback scope on my C-11, I now knew for certain that the "mount from Hell" would no longer be satisfactory with my smallest instruments. What do do next?

I explored practical alternatives by checking the negative reviews of alt-az mounts on the Internet, looking for reports of the various models that would focus on their drawbacks, rather than their virtues. In doing so, I found that almost all the current and easily-obtainable portable alt-az mounts are alleged to be stable ONLY with 80 mm aperture scopes, and nothing larger. That meant that my StarBlast, and my 120 mm f/5 refractor, would be too massive, and the mounts would be shaky. Furthermore, most of these mounts fail to provide enough spacing between the central shaft and the scope, or position the eye-end of the tube assembly near the top of the tripod legs, causing the diagonal to slam into them when the tube is pointed at the zenith. After days of reading complaints on various forums, I sought the advice of my friend Sue French, who is an avid user of a 4-inch refractor. Her recommendation: an Astro-Physics 400 mount, or the current in-production replacement model! It's a wonderful suggestion, but not a device that is justified by a telescope tube assembly that costs a mere $300.

I happened to drop in to my local friendly telescope dealer, "Poniatowsky's Bull Telescope Center", and was taking a hopeless, desultory look at their deluxe mounts (costing $800 to $1600, far exceeding my budget) when one of the employees brought to my attention a gadget that he wanted to sell: a contraption that mated an old Meade SCT tripod (for a heavy ten inch scope) to a tall refractor pier. I made a deal for it on the spot: for far less money than I had expended to date, trying to make something useful out of "the mount from Hell." I attached the EQ-3 equatorial head that came with my Orion 4.7 inch Astro-View refractor to the top of the pier, and with a few modifications was able to get it to work in alt-az mode.

Below, I show the minor changes to the base of the EQ-3 mount: as supplied, the polar axis will not turn completely, from 0 to 90 degrees, but is restricted in rotation. That block has to be removed, and unfortunately it requires some "surgery": grinding it away (I used my Dremel tool to do it.)

A small bit of metal was shaved from the front (behind the aluminum plate which conceals it), which is a sort of "stop" for a protrusion that prevents the polar axis from being fully rotated. Then I removed the fine-adjust azimuth knobs, and replaced them with capscrews, which do not stick out as far as the knobs did.

Finally, I fashioned a little aluminum plate to hold the polar bearing tightly in place. As the above picture shows, the telescope tube now rotates all around the pier without striking anything, permitting me to use my 2" diagonal: the picture at left shows the spot with the closest clearance between the focusing knob and the pier. Most of these changes are reversible, and none will prevent the head from being set up in equatorial mode, if the aluminum plate is removed and the altitude bolts are reinstalled.

With such a massive tripod -- originally intended for a huge scope -- the refractor tube assembly, equatorial head, and counterweight present no problem and don't create a "tuning fork" that vibrates at a low frequency resonance: the mount steadies in less than a second after one has touched the scope tube or focuser. I prefer to use small refractors or Newtonians in alt-azimuth mode, since I don't have to rotate the tube assembly or diagonal when the scope is pointed at varying elevations. I never bother with the tiny, inaccurate setting circles on small equatorial mounts anyway, instead finding objects by means of a red dot finder and star-hopping. So, this arrangement is preferable to me than using my 4.7" scope with the conventional German equatorial polar arrangement.

What's to happen to "the mount from Hell"? The pieces are now all packed away in the original cardboard box, still 'mocking' me every time I walk past its hiding place in a dark corner of the garage. Perhaps some day I can give it to one of our young piano students (as I've done in the past with various cast-off telescopes.)

UPDATE! I've resurrected the pieces of this mount and converted it back to alt-az again (as of the close of May, 2008) in order to serve my newly modified ST80 refractor, with 2 inch focuser. Click here for all the construction details. -- 5/31/08

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First posted 2006; last edited on Saturday 31 May 2008 at 3:29 pm. Copyright © 2006-8 Stephen R. Waldee - All Rights Reserved. All Trademarks or Copyrights are © or Property of Their Respective Copyright Holders.


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