Sunday, January 18, 2015


A CGEM Comes to Chaos Manor South

I didn’t want that much, muchachos. Just a mount that would handle my Celestron C11 OTA for visual work, video imaging, and Moon pictures. It couldn’t be too expensive and it couldn’t be too heavy. And it had to have spot-on goto. I didn’t want to have to futz around with an exacting polar alignment to get that, either. I wanted to be able to point the thing vaguely north and have whatever I requested be in the field for visual (or even video) work.

Deciding which mount would fill that bill was, as I told y’all last time, tough. Till I had an epiphany. What I really wanted was just a bigger Celestron CG5 or VX. Not too scaled up in weight and price, though. Only one mount fit that description and that was the standard Celestron CGEM.

As you also heard last time, I soon got a CGEM on the way from Bob Black at Skies Unlimited and busied myself getting the NexStar 11 GPS, Big Bertha’s, OTA off her fork, not a completely trivial operation, but one that only consumed a single morning.

When I was a sprout, I thought Christmas took forever to arrive, but that was nothing compared to waiting for a big new piece of astro-stuff. Luckily, there were no winter storms and we were past the holiday rush, so the tracking on the UPS site showed the mount and a dovetail for the OTA, which I’d ordered from B&H, were proceeding normally and on schedule for delivery Monday, less than a week after I’d ordered ‘em.

With Bertha squared away and sitting on the table in the sunroom, there wasn’t much else to do. Oh, there was one thing. I moved the Atlas tripod, which features a TPI spreader system, into the sunroom from the garage. If the Atlas and CGEM tripods were identical, I planned to use the Atlas’ tripod for the CGEM. If not, I’d move the spreader to the new CGEM tripod. The Atlas is only used with a C8, so it really doesn't need the TPI spreader to strengthen its tripod.

I fidgeted all through a long weekend, taking occasional looks at the UPS website. Still said “Monday,” but would Monday ever come? I also kept an eye on the Weather Channel. The prognosis seemed to be that I might get some time under the stars Monday. Not much, and there would be clouds, but maybe a little.

Monday a.m., I busied myself working on my latest Sky & Telescope assignment to try to make the day go quicker. I expected the UPS truck wouldn’t roll through Hickory Ridge till around 4. You never know, though, and anything that went by on Pine Needle Drive that sounded anything like a brown truck brought Unk to a window at a run. Mid afternoon actually went quicker than I thought it would. Dorothy arrived home with a nearly flat tire, and by the time I’d got her beloved Xbox (Scion XB) up to the Trax Tires over by the University and got the little thing a new shoe, two o’clock had come and gone.

When I got home, Miss D. reported that nary a brown truck had she seen. Back to Microsoft Word. Not for long. The sound of another truck caused me to look out, and what should I see but a UPS vehicle in the driveway. I headed for the front room (“Music Room”) post haste. Surprisingly, and a little disturbingly, by the time I got the front door open, the UPS dude has already deposited three boxes on the porch and was on the way back to his truck. No doorbell. No request for signatures. Whatever. IT WAS HERE.

“It” being not only the mount’s two boxes, but the single box containing the Celestron D-type dovetail.  I’d had a premonition that only two boxes would appear, that the Dovetail I needed to get the scope on the mount would be MIA. I’d armed myself with printouts from the UPS website in case I needed to make the UPS dude to check his truck one more time, but all three were, yep, there on the front porch.

I wrestled ‘em into the Music Room as a first move. Well, “carried” the box from B&H; it was light enough. The other two were handfuls. The long box that, I presumed, contained the tripod was heavier by far than it should have been, so I suspected it also held the 17-pound CGEM counterweight. The other box? I had to set that down in the den once on my way to the sunroom, my chosen assembly area.

For the next hour or so, Miss Dorothy wisely kept herself out of the sunroom. It was inhabited by a wild man, and packing debris was flying everywhere. I took things slowly and carefully, but after owning a CG5, a VX, and an Atlas, I was on a pretty well-trodden path. Figgered I’d start with the tripod box.

Part of that (double-boxed) box was indeed taken up with the hefty CGEM counterweight. While heavier than the VX’s weight, it was in the same modern style. The mount comes with only a single 17-pound counterweight, and I didn’t expect that to be enough. I was hoping the addition of the 12-pound VX weight would be enough, howsomeever. If not, there was no lack of old (compatible) 11-pound Synta pancake weights ‘round here.

Counterweight put aside, I lifted the tripod out of the box. It was in perfect condition, and at first glance didn’t look any different from the Atlas’ tripod setup nearby. It turned out there was one minor difference:  the peg the azimuth adjusters push against was, as I’d heard, a little taller than the one on the Atlas. I could have exchanged pegs between the two, but I gotta admit, campers, the new tripod was so pretty I decided to use it instead. I’d transfer the TPI spreader bars to the new tripod once assembly was done. I snapped the hand controller holder, the last thing in the box, to a tripod leg and pressed on.

One thing I did to the new tripod immediately was wipe down the threads of the center bolt and apply a thin coating of bicycle chain grease. The last Celestron mount I bought was fatally flawed in that area. After I screwed the VX tripod center bolt into the mount head for the first time, it seized up, and I had to destroy the bolt and the hole it threaded into to remove the tripod so I could ship the whole works back to Celestron. Hoped that wouldn’t be a problem this time.

Now came the pay off, the big Bubba of a mount itself. The heaviest box contained the CGEM head, the counterweight shaft and lock nut, the hand controller, cables, two azimuth adjustment bolts, the manual, and—something of a surprise—a copy of the NexRemote CD. Seeing as how my VX came with a TheSkyX disk, I’d assumed NR was a thing of the distant past. There was also a manual that was no better nor any worse than any other Celestron manual. “Adequate” in other words. I browsed through the thing to make sure there were no gotchas regarding the CGEM, and got back to work.

First out of the box was the hand control, which was a standard model, not the new Plus version. That, I thought, was a Good Thing. Oh, I’ve gotten used to the VX’s Plus HC, but I will never like it as much as the old one with its M and NGC shortcut keys. Anyhow, I set the HC aside along with the declination counterweight shaft and nut and a bag containing two cables, a too-long 12vdc cord and a too-short serial cable. I screwed my courage to the sticking place and lifted the big GEM head out of the box.

First impression? If the CGEM is any lighter than the Atlas EQ6, it ain’t by much. Second? After the tripod’s central bolt threaded smoothly into the mount, and the mount was secure on the tripod, I inspected my new GEM. I was impressed by how much Celestron prettied up the EQ6. You can still see its Atlas heritage, but just barely. Everything is more attractive and modern looking. The mount ain’t gaudy, however. You’ll see some with orange declination and R.A. lock levers and orange-headed altitude and azimuth adjustment bolt heads. Those are aftermarket accessories. Stock, it’s fairly subdued. There’s orange trim around the end of the RA housing and around the altitude pivot, but that is it.

How about improvements? The heads of the azimuth and, particularly, altitude bolts are much larger and easier to turn than those of the Atlas. The altitude scale has also been markedly improved. The cover for the south end of the R.A. housing is streamlined, more modern looking, and easier to screw on. Oh, as with the Atlas, the declination wiring is internal; there is no declination cable to mess with.

Which brings us to the power panel. It’s OK, if on the simplistic side. There’s the now-standard Celestron thread-on power connector, a nice large on-off switch like the one on the VX, and hand control, Aux, and auto-guider RJ-type ports. Unlike on the VX, there is only one Aux port, and like the VX (and CG5), there is no PC port. Luckily, I have Celestron’s (now discontinued) Auxiliary Port Accessory, which adds the PC port so I can connect NexRemote directly to the mount without the use of the hand control serial port (or even having the HC connected).

I screwed the counterweight bar and nut onto the declination assembly, dug up a Celestron 5-amp power supply, plugged the HC into the HC port and discovered the first thing I didn’t like about the CGEM. If I thought the cable on the VX hand control was a little short, I hadn’t seen nothin’ yet. This one was ridiculously short. It was obvious slewing in R.A. would yank the thing out of the holder and leave it dangling by its cord. Luckily, I had a nice coiled extension I bought for the VX from’s Jim Henson. I rustled that up right quick. Finally, I placed the VX counterweight on the shaft, followed by the CGEM weight.

Alrighty, then. Before I could get Bertha on the CGEM, she’d have to have a Losmandy “D” style dovetail installed on her belly. I opened that final box. As I’d expected, there were no instructions, just the (very, very orange) Celestron C11 dovetail bar and a little baggie containing four screws. I was puzzled at first, since two screws were long and two short(er), but a little experimentation showed which went aft and which went forward. The short “place-holder” screws I removed served to fill in the last of the screw holes in the OTA left by removing the brackets that had attached it to the fork mount.

No use delaying the inevitable. I hefted the C11, slid the dovetail into the saddle on the mount, moving it pretty far forward so balance would be reasonable—Bertha is even more rear end heavy (sorry, old girl) than Mrs. Peel, the Edge 800. Done, I took a few minutes to just admire the new Big Bertha. That big carbon fiber tube looked superfine on the CGEM, and I gotta admit the uber-orange dovetail actually added something. I was soon hollering for Dorothy to COME LOOK!

I did a little fine-tuning of R.A. axis balance, placing the CGEM weight near the bottom of the shaft and the VX counterweight (yes, more than 17 pounds of weight was needed) about halfway up. Next was rubber meets road time:  power up for the first time. I plugged the power supply into the mount (the connector fit snugly with no need for spreading connector pins, unlike with the VX and CG5) and into the wall, and hit the o-n/o-f-f. I reckon I’ve got used to the Plus HC, which takes longer to boot, so I was kinda surprised how quickly I got “CGEM Ready” on the LCD. We was good so far.

Next thing I do with any new mount is a fake (goto) alignment indoors. Which was easy. As I told Miss Dorothy, I was comfortable with the mount from the start. It truly was just like a great, big VX.  I set the R.A. and declination axes to their “home” marks (which are a little small if’n you axe me), entered the date/time and other usual stuff, and began a two star alignment. The CGEM stopped with Bertha pointing in approximately the positions the two stars would be in in late afternoon. I didn’t add calibration stars, natch, just hit “undo.” The mount responded with a reassuring “Align Success.”

After my fake alignment, I did a couple of fake gotos. I asked for M31 and M27, and the tube was pointing in roughly the correct places when Bertha halted. The sound? Bottom line is that the CGEM uses servos instead of steppers like the Atlas, and will never be as quiet as her sister mount. That said, the noise level was comparable to that of the VX—well, maybe a little louder than that. The mount also sounded assured and powerful, there was no hint of any struggling with the big OTA. That is the short and sweet of the mount’s arrival, friends. If you’d like more details, have a look at the Youtube video below.

Now to wait for darkness. The sky didn't look overly promising. Plenty of cirrus clouds littering the heavens. The did imply they would begin to disperse at sunset, and that it might even be clear by nine. While waiting for Sol to go away, I got my hex wrenches and transferred the TPI spreader bar from the Atlas tripod to the CGEM, the work of but a few minutes.

I was purty sure that would prevent any stability problems, but if not, I have a set of Celestron vibration suppression pads (they shipped with the NexStar 11 GPS). I could also install the TPI equipment tray on the spreader and load it down with a jumpstart battery or two. The scope seemed solid enough on the mount from what I could tell without doing any of that, but the only true test is under the stars.

When the clouds had thinned enough to encourage me that I wouldn’t be wasting my time, I disassembled the rig and lugged it into the backyard. Verdict? It ain’t that bad. Yes, the mount head is a load, but a bearable one. The OTA? The key is keeping the tripod legs at least partially collapsed so you don’t have to lift the tube high to get it in the saddle. That’s jake by me, since I use the 11-inch 99% for imaging. If I want to go visual, the collapsed tripod is fine with an observing chair.

Alignment was anticlimactic. No different than with the VX. Two alignment stars, then (up to) four calibration stars. As per usual, the first star was pretty far off, the second was closer, and by the time we got to calibration star 3, it was in the cross-hair eyepiece when the slew stopped. One thing that made for an easy alignment was that, instead of a finder scope, I used the Edge’s Rigel Quickfinder. I found I had an extra Quickfinder base in my shop, and it was a no-brainer that it should go on Bertha.

Alignment done, I replaced the 12mm Meade reticle ocular with the 13mm Ethos and had at it. Conditions were not good and were degrading rather than getting better as had been predicted. By 9 p.m., as a matter of fact, we were socked in. That did not prevent me from doing nearly 20 objects, however, and every one of them was well within the field. I didn't just go with easy ones, either. I went after M57, which was close to the horizon, M31 at the Zenith, and objects at all the cardinal points. Only problem was seeing ‘em through the building haze. The mount? Again, just not much to tell. Like a big VX or CG5 in every way.

When the last sucker hole evaporated, I returned Bertha to the sunroom and quitted the backyard for the den and a little cable TV and Colorado Kool-aid. After boring Miss Dorothy with a lengthy recounting of my backyard adventures: “There was M57, no more than 5-freaking-degrees above the horizon. BAM! It was in the eyepiece, easy!”

Was I satisfied? You bet. I hated to jinx it, but this was so far proving to be the smoothest “commissioning period” for a major new piece of astro gear in a long, long time. When I’d calmed down some, I watched episodes of Gotham on the On-demand till my peepers began to close and Chaos Manor South’s resident black cat, Thomas Aquinas, awakened me by tapping on my cheek with his paw, signaling, “Time for you to go to bed, Daddy.”

Tuesday dawned to considerably better weather, and there was no doubt Bertha and her new mount would get a second go. Like Miss D. said, “Don’t want to get caught out down in Chiefland.” Yep, I wanted to make doubly sure all was well, and the way the weather was looking for the next week plus, I wasn’t sure I’d get another chance to use the mount before our CAV odyssey. Yes, there’d be some clear weather, but it would be accompanied by temperatures in the teens. Not exactly Unk Rod observing conditions. After that? Clouds.

Set up went much as before, and so did alignment. What did I learn on this night? It’s better to balance. While the mount didn’t have any trouble moving the OTA to targets with my, er, “casual” balancing, it made a little more noise, sounding more like the CG5 than the VX. I stopped, moved the weights to the places they should have gone in the first place, and realigned.

Following that, the CGEM was noticeably quieter. Gotos? Anything I requested  was—BAM!—right in the middle of the 13mm Ethos or my 16mm Happy Hand Grenade (Zhumell 100-degree eyepiece). What did I look at? Anything apt to show up well in my skies and not too low or behind trees. Probably 25 – 30 gotos before the wind began to blow.

Funny thing about the wind kicking up? It didn’t seem to bother Bertha a bit; no shaking did I detect. A sharp rap on my girl’s rear end (ahem) resulted in vibrations that died out in just a hair over 2-seconds. I probably will add the TPI accessory tray down at CAV, mainly because it’s a good place for the mount power supply, the DewBuster power supply, the Mallincam Xtreme’s 12-volt battery, etc., and I suspect that will steady us down even further. Not that More Better Gooder is needed anyway in my judgment.

Any new telescope, and that’s really what Bertha is now, requires a period of adjustment, a "commissioning" as they say in the pro-astronomy biz, but I suspect set up will become easier the more I use the rig. I don’t think I will suddenly stop using the VX/Edge 800, muchachos, but Bertha is danged sure going to get out a lot more than she has over the past five years, and that is all I wanted.

Next Time: Down Chiefland Way...

Well my open box CGEM arrived today by UPS from CA. I am very impressed with the quality and sturdiness of the CGEM vs the older CG5 I had. The CPC 11 is now a C11. Thanks for the video only took 20 minutes to assemble and mount the optical tube, a bit of duct tape with a couple of 5 lb. hand weights (thanks to the wife) and the balance is spot on (11 lb. weight on the way).

Pat Utah AKA NSN Alien Observatory
Well, Uncle Rod, followed your in the house Alignment procedure, tried it here, then went out tonight in a sucker hole and got 2 plus 3 alignment / calibration stars. As you said, bang right on goto performance and very good tracking.

As a side note, mounted the Rigel Quick Finder in place of the stock 9X50, and presto (after 2 years trying and reading the directions again) I got the Red bullseye. Apparently looking thru the Rigel unit backwards, it will never work as advertised. :-)

Pat Utah NSN AKA Alien Observatory
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