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(Half) Hitching To Nirvana — a review of the Half-Hitch Mark II Alt-Az mount


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(Half) Hitching To Nirvana — a review of the Half-Hitch Mark II Alt-Az mount

By Doug Reilly

I recently resumed my search for the perfect telescope mount. Such a thing is a mythical construct, and yet I’m sure other astronomers have also yearned—and searched—for such a thing. Of course, “perfect mount” can and probably does mean something unique for each observer. What a star-hopping visual observer wants and what an imager wants are going to be quite different. Among visual observers the individual requirements are no less distinct; planetary observers may value most tracking and a solid footing so vibrations don’t rob the observer of that (equally elusive) moment of “perfect seeing”, while hunters of faint fuzzies may value most a mount that makes manual movements as smooth, precise and fluid as possible to facilitate star-hopping.

I’m a visual observer who likes to star-hop (I’m still learning the sky) and I enjoy a wide range of astronomical objects. I’ve never been able to restrain myself at buffets. One of the best mounts I found for my style of observing was a Losmandy GM-8. This American-machined equatorial mount has friction clutches instead of the more common axis locks and slow-motion controls, and so it’s motions are smooth and fluid like a well-crafted dobsonian, and yet it has the dual advantages of tracking and fine aiming adjustment via the mount’s motorized axes and hand paddle controller. It was the best of both worlds combined for me, smooth manual motion and electronic tracking.

The downside of that mount was weight—it wasn’t light—and the somewhat torturous eyepiece positions the mount would create with a Newtonian reflector mounted on it. To be fair, any EQ mount would do the same. I added a wheel to my OTA to run against the first tube ring so I could easily rotate the tube.

In balance, I loved that set up. But dental bills caused me to sell it. I went back to my little dob mount and was content, mostly. Well, at least when I didn’t think about my GM-8 as I lost that faint fuzzy after spending 20 minutes trying to find it.

And then I got the bug again. The little voice started saying to me “Maybe there is something better out there.” I tried a Takahashi Teegul mount, and liked it. Smooth axis motion and manual slow-motion knobs with no need to unlock the axes. Plus plus and plus. The negatives? The side-mounted scope position made the scope setup a bit tippy. A friend of mine who also owned a Teegul had a counterweight bar machined for his Teegul and mine, and that mod made it work much better. Of course, then it was even heavier than normal, and the Teegul wasn’t slight to being with. Minus.

Then I saw an ad for the Half-Hitch alt-az mount. I had seen them before. But for some reason I took notice this time, and got to thinking. Lightweight? Check! Smooth manual motions? Check! Manual drive controls? Check! What didn’t it have? Well, motors and tracking, though good manual drive controls can mitigate the need for tracking if the mount is stable and controls fine enough. And the Half-Hitch had an extra enticement to make up for its lack of whirring gears and motors: a built-in encoder system for Digital Setting Circles. I had never tried DSCs before, and generally as a budding star-hopper I kinda look down on such electronic aids, except when I’m doing outreach in a light-polluted city and can only see the brightest stars and the moon. DSCs might help me show people more than a crater.

All in all, it looked like a well-machined, well-designed and precise instrument. I was intrigued. And, as I have a soft-spot for the little Tuckers out there trying to make a better product without the big R&D budgets and the tremendous advantage of Asian production, I decided to give Half-Hitch Telescopes a deeper look.

The mount was invented and is manufactured by Charles Riddel of Half-Hitch Mounts. Charles is well known for perfectionism, design brilliance and cleverness. His website does a very thorough job of explaining the ideas of the Half-Hitch mount. I called him up for a chat, to see if he thought the mount would work for my intended OTA, a 6” f/7.5 off-axis Newtonian in a lightweight tube of my own construction.

I was concerned because the Half-Hitch site’s images—and there are lots of them—mostly show shorter-focal length refractors. I figured this was partially marketing—it’s a high end mount that would look great under a Tak, AP, Televue or other high-end apochromatic refractor. It’s also not inexpensive, coming in around the same price as a used GM-8.

Charles reassured me that the Half-Hitch would work with any scope up to an including 6” newts (check!) and even 8” SCTs. He even pointed me to a photo on the Half-Hitch site of a Russian-made 6” Maksutov-Newtonian, which is, after all, very close in size, weight and configuration to my off-axis newt. He did mention some extra attention I’d have to pay to balancing the OTA, and that the manual drive control knobs would not be as conveniently accessible as they would be if I was using a scope that had a rear-mounted focuser, like a refractor or a cassegrain of any sort.

He also told me that he was shifting his efforts to the “Quarter-Hitch” mount and temporarily suspending production of the Half-Hitch. What’s the difference? The Quarter-Hitch does not have the built-in encoders standard. It’s the Half-Hitch, paired down to simplicity. The Zen Master at the monastery of Zen alt-az mounts. When I mentioned my thoughts about using the DSCs for outreach events, Charles mentioned that he did have a few Half-Hitch Mark IIs with encoders on the table, if I was interested…

Well, the price was right, and a few weeks later (Charles kept in good touch about when the mount would ship) I got a well-packed box.

The Half-Hitch is certainly beautiful. It looks a bit like the Terminator’s arm. Although dimensionally larger than the Teegul, it’s far lighter and more graceful. It’s shiny in places, flat clear and black anodized in others, and it looks like a load-bearing structure. I think the only plastic on it is the knobs on the saddle and a few washers and cable clip. The rest is aluminum and stainless steel and brass.

The mount is crafted with extreme attention to detail. It has a tiny bubble level inside the L shaped arm. It has a little platform above the saddle for a finder scope. It has a caliper brake that can lock or add tension to the altitude axis. It has manual drive controls for each axis, and this is a unique system. Each axis has a drive disk made of anodized aluminum and a stainless steel pinion that is moved directly by the slo-motion knob. The action is very fluid and precise.

The documentation is good and explanatory. The most critical set-up requirement for the Half-Hitch is proper balancing of the OTA. Charles calls this “two-axis balancing”. You have to adjust the OTA for front-back (altitude) balance, either by shifting the OTA in its rings, or shifting the unique dovetail back and forth in the saddle. I like to reserve saddle adjustments for fine-tuning later on (a use encouraged by the inclusion of very precise measurements on the saddle and dovetail for calibration and repeated settings) so I moved the scope first in the rings. Charles suggests you don’t just balance it so that it doesn’t flop forward or backward when the drive is released, but that you “balance dynamically,” that is, use the slo-motion control to feel if there’s more resistance going up or down in altitude.

The second axis of balancing is up/down, meaning how high up the scope sits in the saddle. A scope that is too high will tip forward when the scope is pointed towards the zenith, too low it will tip upward. I was skeptical of this at first, thinking it must be the previous balance at issue. But alas, Charles is correct. I lowered the saddle plate to the bottom position and the scope held still no matter where it was pointed.

If the above gives the impression that the Half-Hitch is sensitive to balance, or rather, to imbalance, I think that’s correct. Fluid motions rest on proper balance as the Half-Hitch doesn’t have the large friction bearings other alt-az mounts might have.

A balanced OTA is one thing, what about eyepieces? I have a wide range of eyepieces, from the biggest/heaviest (a 32mm Televue Wide Field) to the smallest (a 4mm orthoscopic from Univeristy Optics). On any given object I’m likely to use several eyepieces, starting with the 32mm as a “finder”. For planets, I might get down to that featherweight 4mm In addition to the two-axis balancing mentioned above, there is a small stainless steel weight attached to a rail just forward of the saddle plate. This “balance trim” is designed to make up for small differences in eyepiece weights. Does it work going between the 32mm Holy Hand Grenade and the 4mm Mouse that Roared?

No. Charles does sell a larger balance trim, and I suppose one could use two of them. And there’s one last adjustment you can make; the altitude caliper brake can add friction to the altitude axis that can null out the effect of a small imbalance.

But I’d recommend the Half-Hitch for observers with a fairly uniform set of eyepieces, weight-wise. The other alternative is to combine the balance trim (which can be labeled on the top of the sliding bar) with adjustments to the OTA. For observers that primarily observe with one eyepiece… I know people who use almost nothing but a 13mm Ethos, for example, or end up keeping their 20mm Pentax LW in the focuser most of the time, then a little shift of the OTA in the saddle for a different category of eyepiece is not such a hassle. This is where a 3-6mm Televue Nagler zoom comes into its own, providing essentially one-stop planetary viewing.

The reward for this attention to balance is an observing experience that I could best describe as alt-az “Zen”. The manual drive controls are extremely responsive and smooth. They suffer from none of the “stiction” that plague many dobs and other alt-az mounts. Stiction is the force needed to start the scope in motion against the friction of the bearing surfaces. Too much stiction can turn the most precise of nudges into something like a blind FLT jump in Battlestar Galactica… you have no idea where you will end up. This can lead to frustration and fatigue, and, in public settings, to uncomfortable pauses in the observing session as you try to zero your target.

Truly the Half-Hitch moves like nothing else I have experienced. It doesn’t feel like a slo-motion control on most EQ mounts or on the Teegul… probably because there are no gears at all on the Half-Hitch. There is also thus no backlash. High power tracking is very easy. You can simply push the mount around like a Dobsonian, or use the manual drive controls which can actually move the scope pretty fast if you roll the knobs in the palm of your hands.

The mount is very rigid. On a very hefty Stellarvue Stableblock Tripod, damping times were less than 2 seconds. On a shorter, lighter Vixen wood tripod from the Super Polaris era, the damping time is about 3 seconds. Switching eyepieces is easy. You apply the caliper brake via a knob next to the altitude slo-motion control and it locks up that axis pretty tight. One interesting result of the drive system design is that applying the brake beyond a certain point disengages the drive pinion so in a locked position the slow-motion control will not work.

In addition to my 6” off-axis Newtonian, I also used the scope with a Stellarvue 80/9D, an excellent and overbuilt refractor. This confirmed what Charles had told me and what my first few observing sessions with the Newtonian confirmed: the mounts ergonomics are designed for refractors. The manual drive controls were within easier reach and the overall experience was more comfortable. Given that it’s owners of refractors (which are more expensive per inch of aperture than most reflectors) who will be most interested in a high-end design like the Half-Hitch, this is good thinking on Charles’ part.

The Half-Hitch does not reach zenith with either of my scopes, both of which are fairly long, however. It can get close, but in most cases the back of the scope will hit the mount/tripod. To avoid this, the Half-hitch has a zenith stop installed on the altitude axis. This is adjustable and indeed, even removable if you have a scope that’s short enough to swing through. Is this a minus? I think it’s a trade off. With the Teegul, you could reach zenith if your scope could fit between the tripod legs. Mine did within a degree. The Half-Hitch is more limiting in this respect. But again, it’s compromises. What you gain is the fact that, because the telescope tube is right over the central axis of the tripod, the setup is sturdier and less prone to “tip”. Charles commented on this in a thread about the Half-Hitch on CN Forums:

Anything that is built will contain design trade-offs. In creating the Half Hitch I elected to favor a small offset and low moment of inertia over absolute zenith access for all 4" refractors. We know that alt-az mounts are inherently awkward at the exact zenith – so  I considered access within two or three degrees of the zenith to be close enough for scopes with long tubes.

Part of my reasoning for trying the Half-Hitch mount was to bring the power of Digital Setting Circles to my public outreach events. I like to take my telescope to downtown Geneva and park it on a sidewalk and try to show people the universe. Geneva is pretty light polluted, so the idea of the DSCs on the Half-Hitch was really attractive. The Sky Commander XP4 Flash computer fits on a nifty fold-out platform. It velcros on, and the control cables, otherwise neatly hidden in the mount, have a few loose inches near the platform; they hook right up. The system works as advertised, placing the object in the eyepiece with ease. I’ll comment on the Half-Hitch’s potential for outreach in my conclusion.

I recently bought a Byers 58—an equatorial mount made by Ed Byers in the 1980s. It’s in the same weight class as a Losmandy G-11, and shares several similar features, including the friction clutch bearings. I compared both mounts using the same OTA. Both mounts had fluid motions and good fine controls, with a nod to the Half-Hitch because the Byers slow-motion controls have some backlash and are much harder (by design) to turn. The Byers mount is more stable. On the same Stableblock tripod, damping times were reduced to under one second.

But then I compared them on something else: carrying them out of my garage. The Byers mount takes 50 pounds of metal to achieve that damping time. The Half-Hitch weight in at 1/10th of that (that’s five pounds). Going back to the Half-Hitch after a few nights with the Byers 58, I was relieved…I almost threw my observing setup through the ceiling of my garage, so used to hefting the massive equatorial I had become.

Charles Riddel markets the Half-Hitch as the ultimate grab-and-go mount. Does it succeed?

Yes, I think it does. Like every design, it represents priorities and compromises. Charles wanted a mount with precise, stiction-free motions and manual drive controls that was lightweight for maximum portability, and maximum stability for the weight of the mount. Given those parameters, the Half-Hitch (and the current Quarter-Hitch) succeeds. It’s quite an achievement.

That said, is the Half-Hitch for you?

It depends. I’d recommend the Half-Hitch for:

  • People in search of the ultimate, lightweight “grab-and-go” scope. It would be a great mount to travel with, too, aside from the slightly ungainly shape. No other mount offers so much for so little mass.
  • People who are willing to get the balance right and get used to the “feel” of the mount. It takes some getting used to, but one’s patience up front is rewarded with a very Zen-like experience. Remember that Zen has often come to mean “care free” or “easy going” but in fact Zen demands lots of practice. So I think “Zen-like” in this instance is actually on the mark.
  • Owners of short refractors and small cassegrains. The Half-Hitch feels made for you! The locations of the manual drive controls are where they should be and you’re the least likely to run into tripod-clearance issues. For those with Newtonians, it’s still good but a little less ergonomic. The shorter the tube the better at keeping the controls in easy reach.
  • Observers who appreciate the creative output of small-scale dedicated companies who make products with attention to detail and customer service as a priority. Half-Hitch has an active Yahoo Group and Charles is very good to deal with.

Conclusion

I’ve compared the Half-Hitch to a fairly disparate group of telescope mounts. To me, this speaks to the unique position of the Half-Hitch. Nothing else has the same set of features or same design goals. It is idiosyncratic to Charles Riddel and was definitely not designed by a committee. These are good things in the age of collectively-designed, mass-produced and mass-marketed products.

The Half-Hitch is not inexpensive. The current Quarter-Hitch Mark III, a bit beefier than the mount tested and lacking the DSCs and encoders, is about $800. That’s $300 more than the Takahashi Teegul and significantly less than the other premium hand-made alt-az mount, the Discmount. The $800 price tag currently gets you all the options, including the finder platform and balance trimmer, and it also includes the saddle and dovetail plate, things that you would need to buy for the Teegul if you were going to use anything other than a Takahashi telescope with it. That puts them about dead even price-wise.

I’ve owned and used both and both are excellent. The Half-Hitch provides the more refined experience and it’s lighter to boot with greater capacity since it won’t tip. For outreach I’d prefer the Teegul because it’s easier to lock it down and less likely to move when nudged, but for my own observing the Half-Hitch fits the bill.

Therein lies my only true reservation about the Half-Hitch mount: its utility as an outreach tool. I have to admit I don’t think that’s what the mount was really intended for. Everything I observed pointed to the idea that the Half-Hitch is a very personal kind of device, meant to bring the discriminating observer closer to astronomical objects he or she is trying to observe.

Its main strength—precise and stiction free motions—is also its weakness in social settings. The altitude brake and azimuth lock do tighten up the axis, but at the expense of the manual drives, and tracking by pushing the scope around (because of the friction you’ve suddenly introduced) is difficult. The problem is that with the public, you do often want to lock the scope down. People have a tendency to hang onto or lean into a scope, despite how they’ve been instructed. The Half-Hitch will simply swing away in spite of the brakes, requiring the host to re-aim the scope.

This is a niggle considering that the Half-Hitch is neither designed nor marketed for this purpose. I could just as easily try to get away with commenting on the mount’s inability to heat up my hot chocolate. But since a lot of us do a variety of kinds of observing in a variety of setting, we often look for equipment that can also do it all.

The Half-Hitch does a lot. But it’s a different beast from heavy equatorials or pretty much any other alt-az mount. I tried to capture some of its independent spirit in this review. Grab the Half-Hitch and go out under the stars, spend a few minutes learning how to use it, and you’ll not soon want to let go of it.

Note: My Half-Hitch is a Mark II. The current Quarter Hitch is a Mark III, which I am told is even sturdier than the Mark II.

Doug Reilly blogs on astronomy and astronomy outreach activities at www.punkastronomy.com. He’s a visual observer of deep space objects, planets and double stars since 2001 and lives in Geneva, NY.


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