The NJP’s state when it got back from “repair” was pretty sad. I mean, even a poorly working NJP is better than I’d ever really gotten with the G-11, but it needed some TLC, badly.

Before I could get to work on the mount, though, I had to put the observatory back in order. I had never really cleaned up after the trip to GSSP last year, and stuff was really starting to be piled up, making it tough to move around, let alone do intricate mechanical work.

So I spent some time getting stuff put away and horizontal surfaces cleared and things moved to the walls where possible. It’s not totally spic and span, but it’s looking a lot more like normal now.

So. The mount. I dismounted Veronica, pulled off the saddle and adapter, and started looking at the Dec axis first. I couldn’t really tell what was going on right away, so I kind of just started ripping things apart until I figured it out. I found out that the gear attached to the motor actually has a little play in it, which means that I was not going to be able to get all the play out of the Dec axis. But it was pretty minor, so I decided that I’d just move forward.

I put some thin paper in between the gears (I used party streamer, because I couldn’t find my Zig Zags). I pulled out my feeler gauges, and made sure that both pins were seated the same amount, with the gears meshed. It took a couple of tries, but the gear mesh is now nice and tight, both bracket pins have the exact same spacing, and, wonder of wonders, when I put the gear cover bracket on, I was able to adjust it so that it no longer scrapes! While I had it apart, I noticed that someone had taken a file to the edge of the cover. Not really a normal method of repairing this part; I could have done that myself if I’d known that was the method to be used. I think I could get a little more clearance, by holding the bracket in a different position relative to the mounting posts as it got tightened up. It’s clearing now, so I’m not going to worry about it.

The adjusted Dec axis feels really nice; I powered up the mount and confirmed that it would run in both directions.

With the Dec axis completed, I stopped to think a bit about the RA axis. The RA axis came back to me with a lot of slop. I really wanted to take out the backlash, but there are a lot more moving parts involved in getting the RA axis diagnosed. As I’d already had the axis mostly apart before, as I tried to figure out if I could adjust the reticle myself. I had decided that the reticle was too complicated to mess with, but this time, I thought I might be able to find out what was wrong with the backlash.

It turned out to be a pretty simple repair.

First, I unscrewed the rear cover, which revealed the main axis cover. The main axis cover is mottled black, and has 4 set screws that hold the machined brass RA axis in place. With the setscrews loosened, the main axis cover unscrews, to reveal a conical bearing, conical bearing seat, and a few large washers. From my many times messing with the G-11, I realized that, at this point, I could probably just pull the RA axis out.

This suspicion turned out to be well-founded.

I found a soft place for the Dec axis (with RA shaft still attached) to land (this needs to be thought-out, because the cable harness is still attached), and out it came.

Doing this revealed the main RA gear, the upper conical bearing, and a thrust bearing setup (washer-bearing-washer). Under the main RA gear, there is a “ring” of metal that gets squeezed by the axis lock. That ring’s housing attaches to the Dec axis housing via a very large machine bolt.

With the gear train of the RA axis all apart, I started hunting for sources of backlash. There were essentially 4 places that could have been problematic:
1) play in the main gear attached to the motor shaft
2) gap between the motor shaft gear and the worm shaft gear (the “normal” place to adjust the axis)
3) improper centering of the worm gear housing (more on this in a bit)
4) play in the RA housing somewhere (not something I’d originally considered)

There was a tiny amount of play in the main gear. A little less than the play in Dec. Again, I decided there was nothing I could really do about it.

The gap between the gears seemed about right; I later ran a paper between them, and it seemed fine. There was still a little play present, but with the gears gapped properly, This didn’t really seem like something that I was going to mess with.

The worm gear housing is definitely not centered in the main gear housing gap. I don’t know what that’s about, but I decided not to change it; I was looking for something “simple”.

And I found it.

The large bolt that holds that RA shaft lock housing to the Dec axis was very loose. The two housings could shift past each other by several millimeters, probably as much as 1/2″. This is just shoddy work putting the mount back together. Nothing else could really explain it. I used my finely-calibrated index finger to confirm that I had the two housings lined up properly, popped a big Allen wrench into the bolt, and was able to tighten it about half a turn before things felt secure. I re-checked to make sure I was all lined up, gave the bolt another tweak, and started reconstructing the axis to see if I’d made a difference.

Putting the axis back together was pretty straightforward; get all the junk on in the right order, make sure everything is lubed properly or it won’t fit (more on tolerances in a bit), put all the parts together, and once I screwed the mottled black RA main axis cover, everything tightened up and into place. I did a quick test to see how the axis felt, and was impressed. I re-tightened the set screws, reinstalled the rear cover, and spent a little time getting all the greasy fingerprints (some mine, some left by the professional “repairs” I’d just had done) off of the mount. With everything tight and back in place, I checked the backlash in RA. It was down to well under 1mm. There is still the tiniest amount of play in the axis, but it’s certainly down in the “acceptable” range. I might try to tighten it up a little more, if I find it to be problematic, but I was ready to declare the mount repair a success!

While I had everything off of the mount, I thought that I should rotate the pier top a little; the way it’s set up, I have to run the mount’s Azimuth all the way to one stop. I pulled the mount, figured out which direction to rotate the top, rotated it, then re-leveled the pier. I actually kind of like leveling, when I have a good tool and a good surface to work with. I had both, and the leveling only took a couple of minutes. I put the mount back up, and moved on to the next task.

I thought about whether to remount Veronica, and I decided that I should polar align with the mount unloaded first. So I left Veronica sitting there, waiting for the sun to set.

I had one last thing to do before sunset, though; the polar scope illuminator has always been a little flaky, and I decided that I needed to fix it. I messed around with it quite a bit, and finally found an LED that would work as a replacement. I de-soldered the original LED, put in a new one, and was pleased to find that the new LED looks very bright. I’m glad that I didn’t ask for this to be “repaired” professionally. For the price of an LED and a couple minutes with a soldering iron, I probably saved myself a few hundred bucks. The new illuminator is visible even during the day, so I was able to get it reinstalled on the mount and all ready to go for sundown.

After sunset, the sky was clear enough to polar align, so I did; using the new reticle with the fixed illuminator made the process simple. I reset the mount’s bubble level to be properly arranged for the new reticle; it’s nearly in CW-down position, but not quite.

I added some Velcro to the saddle and to the USB hub and DSUSB, so now I can just put the cable harness right where it needs to be.

I played around a little with saddle placement. I think that eventually I will want to figure out how to offset the saddle, but for now it’s centered.

I got Veronica back up and cable harness attached. Spent some time getting the balance right. Once Veronica was all mounted up, I pointed over to the moon and focused the camera.

Suddenly, I was ready to start imaging!

Well, ready to test out the imaging rig with the newly-repaired mount, anyway.

I pointed over at Alkaid in The Big Dipper, sync’d the mount, and then did a GOTO to M51 nearby. 3min unguided left some star trails, so I fired up the guider and re-shot a 3min exposure. The guiding accuracy was down in the 0.07pixels (about 0.4″) range in both axes. The stars came out very round, as you’d expect.

I realized that I didn’t have the LPS filter in place, so I reinstalled it, pointed back at the moon, and refocused. Turns out the LPS filter gives a little extra backfocus. Nice! Back to Alkaid (you gotta love the simple pointing model), over to M63 this time, and another 3min shot. Very nice looking galaxy. Exactly what you expect from a 3min shot.

I need to tweak the polar alignment with WCS. I need to get autofocus and plate solving working again. I need to clean the camera optics. There is always stuff to do.

But I hereby declare Ad Astra Observatory at Newark, CA up and running once more.

WIth the NJP back in the observatory, I spent a little time trying to get Trixie mounted up, to test out the rebuild.

I was a little worried about how the mounting plates were going to work on Trixie.

On the other hand, I was also worried that things were going to rip apart, strange cracking noises, and a number of other things.

Yeah, so it turns out that my fears about the mounting plates were well-founded. Because of the way that the plates attach relative to the truss tubes, there is not enough space for the saddle knob. sigh.
I could replace the knobs with machine screws, but I am also thinking that I might just use a different mounting plate. I just bought a Casady Triad Bar, which is designed for mounting 3 scopes side by side, but I don’t really have saddles to use with that anyway, and the Triad is several inches longer than the DC17.25 plates I’m using, so I might be able to figure out a win in fairly short order. It’ll take a little time.

One thing to note: I finally got to use both my 3rd NJP counterweight and the Beer Can extension! Man, Trixie is heavy. I got things “kind of” balanced in RA; it was still very much “over here, it’s CW heavy, over there, it’s scope heavy” with weights in the same position. Yikes. I will have to spend some time scratching my head over all of it.

Oh, and I really need to find an easier way to mount the scope. It is a real back-breaker to get up to eye level. Maybe I can figure out some kind of way to mount it while Trixie is standing on the ground…

I found a couple of cool places where I could prop Trixie against a wall while still on the mount, so I could mess with CW without having to keep a hand on the CW shaft. It is one big scope. Honestly, I’m not going to be able to really automate a photo run with Trixie inside the observatory. I’m going to have to be out there, babysitting a lot, to make sure the scope isn’t grinding into a wall.

Good news, I didn’t hear any strange wood cracking noises. I didn’t get a full chance to test things, but this is good news. And really, I think the new OTA is more than stiff enough.

I have an idea in my head how to fix the mounting plate. It will just take a little time. And a screwdriver.

Don’t worry, Trixie. You’re still looking “go” for photos. Soon. Just please let me get the scope on the mount and then not move it for a few months…

My NJP is future-proofed.

According to Texas Nautical, nobody but me has yet requested the new, updated polar scope reticle for the NJP. The old one is good until 2015, so I suppose it will be a little while before people really start getting desperate.

But this means, of course, that I’m (possibly? probably?) the first person in the Western Hemisphere (North America, certainly) to have one of these. w00t!

Here’s a photo of the thing:

Yes, the image is a little ghetto. But, eat your heart out, Tak owners! 04026 is some good.

Now I just need to get an updated version of TakAlign, and I’m golden…

Finally.

Ad Astra Observatory at Newark, CA is back in business.

The UPS guy dropped the very heavy box containing the mount around 3pm.
I’m not entirely happy with the state of the mount post-repair, but that’s another post.

I put 04026 back on the pier, and started preparing for sundown.

I tried to mount Trixie, but that’s going to take some tweaking. Again, another post.

The LED in the polar scope illuminator is very dim. I tried new batteries, cleaning the contacts, and various tweaks. I finally removed the Tak illuminator, and tried out the LED from the guiding eyepiece. That took a little rigging, but worked… eh, ok. I ended up using a red flashlight , holding it over the end of the polar axis, tweaking the mount, repeat. It took some time. After about 90 minutes, I had Polaris where I wanted it. With a decent illuminator, it would have taken minutes, if not seconds. I did a quick test of the reticle alignment, by rotating the RA axis through 270° or so. It was difficult to get a perfect reading, but it looks like this reticle is installed properly, leading me to believe that I’m not crazy and that the old reticle was out of alignment. Nifty!

To really test the polar alignment, I needed to mount up a telescope.

I chose Veronica (had to remove one of the Dob bearings ), and got the mount balanced, eyepiece and finder installed, and finder aligned. All of this went pretty quickly.

I pointed the mount at M42, starting to cloud up, but I could still see the nebula. I let the object drift across the eyepiece a little (I hadn’t hooked up power yet); things looked ok.

So I dug out the hand controller and a power cable. The plug sockets are much tighter now; cool.

I recentered the nebula, and came inside to let it all run for awhile. I went back out 20 minutes later, to find the nebula still centered, and the same starfield in the eyepiece.

I decided to take a look at Saturn. Man, I am so glad to have the rings opening up again! Just gorgeous. I left it at high magnification (200x) to further check the polar alignment, but I’m pretty well sold that it’s close enough for visual use.

Welcome back, 04026. It’s nice to have an observatory again.

And thank you, astronomy gods, for a clear night to test my mount.

The mount came home under a cloud of controversy.
The folks at Texas Nautical were not exactly pleased with me, but they made good on the charges for the repair, so I was waiting for the mount to arrive so that I could determine that all is, in fact, well.

The outer box was well-sealed and in pretty good shape. The box was marked “Heavy”, “Fragile”, and “High Value”.

The packing between the outer and inner boxes was pretty skimpy; I don’t know if those bubble-wraps ever had air in them, but they were pretty flat when the mount arrived.

The inner box appears to be the same one that the mount was sent in from Japan.

I opened the inner box to find one of the pillows I’d packed with the mount on top, and a bunch of familiar-looking packing paper as well. Under that was a bit of bubble wrap, and several thick pieces of styrofoam. The mount had clearly settled and shifted some during transit, as a few of the inch-thick pieces of styrofoam were dented so badly that there were bulges on the back side of the piece. The styrofoam piece covering the polar scope was dented so badly that it clearly showed the triangle-shaped logo that’s on the polar scope cover. There was a small tear in the bottom and one side of the inner box; the side tear went through.

The mount itself was inside a plastic bag. That kept the little bits of styrofoam off of it.

I unpacked the mount and got it carefully to its pier in the observatory. It felt good to bolt the mount back down; home again.

At a glance, I was a bit surprised to see dark greasy fingerprints all over the mount housing. This is not the sort of handling I would expect from a quality-run shop like Texas Nautical.

When I sent in the mount, I listed 6 problems that I wanted fixed specifically, as well as a request for a “wellness check” on the mount:
1) Polar scope reticle misaligned with the RA axis
2) Dec axis gear housing scrapes the Dec setting circle
3) Mount runs too fast in RA
4) Temma box connectors are wobbly
5) mount is missing upper polar scope cap
6) mount is missing elevation axis knurled lock nut

Of these, I found:
1) New polar scope reticle was installed, as ordered. I will have to check the alignment with the RA axis once it’s dark.
2) Dec motor bracket was replaced (I paid parts and labor), and I was assured that it no longer scrapes the setting circle. This is not fixed. The setting circle is still being scraped by the motor housing cover. I’m not sure what to say about this; I spent almost $200 on this alone.
3) I can’t check the RA speed until I get an autoguider hooked up, although I’m given to understand that Takahashi runs the mounts 0.1% fast in RA on purpose, to help guiding.
4) Temma box connectors are nice and tight now. Very cool.
5) and 6) neither of these parts were replaced, nor were they ever mentioned by Texas Nautical.

I also noticed that the polar scope housing was loose to the touch; I hand-tightened it. As well, the RA main gear cover plate was loose to the touch, and there is a paint scrape on it that leads me to believe that it is rotated from its original position. After some trial and error, I was able to get this so that it’s not loose and also doesn’t bind the axis, although it’s still rotated out of position.

There is a large amount of backlash in the RA worm mesh; it used to move not at all if I grabbed the Dec axis and tried to turn it. Now it wobbles back and forth about 1mm.

There is a new sticker with the serial number on it, taped to the side of the Dec axis. I’m fine with it, it’s just new.

Some of this could be blamed on UPS mishandling the package; stuff rattles loose on a big heavy object like this.

But, frankly, I’m horrified that I paid for 4.5 hours of bench time to receive a mount that has had only 2 out of 6 requested fixes completed properly, one more paid for but not completed, two completely ignored, and several things in worse condition than when I shipped it.

From what I’m seeing, as long as everything internal is OK, I have maybe a weekend’s work ahead of me to put the mount back in proper order. But I am sure wishing that I’d saved my money and fixed the thing myself. Minus the reticle (which would still be useless without this boondoggle), I would have been out for the Dec Motor Bracket (a $100 part), and could have gotten the mount most of the way towards where it sits today.

I’m happy that I have the new reticle. Now the mount is good until 2050. I’m happy that I have the new motor bracket. In theory, I’ll now be able to fix the scraping problem.

To be tested: polar reticle alignment, RA speed.
To be fixed: RA backlash, Dec Motor Bracket, polar scope illuminator (to be fair, I didn’t ask them to look at the illuminator; I have enough electronics skill to fix an LED and Pot)

Onward.

NJP 04026 is on the way back to Ad Astra Observatory!

The repair bill was paid, and it was shipped out UPS Ground from Takahashi America today. I expect I’ll receive it in a week or so.

The mount is apparently working up-to-spec at this point, which is good to hear; the guys at Takahashi America did a good job working through the maintenance and punch list.

There was a bit of a hiccup regarding the Japan leg of the trip; apparently it was not possible to remove the RA shaft from the Dec housing, so they sent the whole Dec axis (with RA shaft attached) to Japan. Takahashi graciously picked up the shipping charges for all that extra weight, though, so I only had to pay for parts, labor, and shipping the RA axis shaft itself.

The guys in Texas came to the same conclusion that I did; it seems like the mount was dropped at some point. My bet is on the way to CA from Teton Telescopes. The packing job was just OK, and big heavy box + so so packing = not the best result. But, sight unseen, my understanding is that Takahashi America have brought the mount back to correct operating condition.

I think that NJP owners who want to get their polar scope reticles replaced when they run out in 2015 should band together to help Takahashi America get an optical bench so that the replacement can be done here in the US. Some machine shop time to build them a jig and a correct target (at the correct distance) should be all that is required. I bet Takahashi America would appreciate being able to do this in-house, and it would save the NJP owners of the world a bundle on this necessary upgrade.

All told, there were just a couple of parts I needed; the reticle upgrade, and a bent Declination motor bracket. About 4.5 hours of bench time was enough to get the mount back in proper order again.

I doubt I’ll have to get the mount repaired again while I own it; It’s a very sturdy piece of hardware, and I baby it, of course.

The clouds will no doubt arrive just in time to welcome the mount back, so I have no idea when I’ll be able to get it out under the sky again, but it will be a secure feeling to have the beating heart of my observatory back, recent Dobsonian excursions notwithstanding.

Godspeed, NJP 04026. Safely go and safely return again.

I gave Takahashi America a week off of NJP updates. When I called them today for an update, they said that the part that’s in Japan is complete and in transit back to Texas. He said that he expected it back “in a week and a half”. Yikes.

Anyhow, he said that the Chief Engineer was the one who’d removed the RA axis, and he’d make sure it got reinstalled when it came in, then move on to the rest of the repairs on the mount before shipping it back to me.

I guess I’ll give them another week off and check in sometime the week after that.

It’s the waiting that gets you.

The RA axis has been received in Japan. No further update on price or ETA yet.

It’s been really clear out lately.

sigh.

As I suspected, the RA axis of 04026 had to be sent to Tokyo to get a new reticle installed (and hopefully aligned this time).

I expect it’ll take a week for the part to get there, a week for them to turn it around, and another week to get the part back to TX. Until then, it’s just a waiting game.

Of course it’s been clear for about 2 weeks in a row now. Everyone is loving the spring weather. Grr. Last year, it rains into June. This year, clear in January.

You’re welcome, everyone.

The NJP arrived at Takahashi America in TX on Friday afternoon.

After not hearing from them by today (4 working days later), I gave them a call.

They are hard at work on the mount. They replaced the broken Dec bracket (that was causing the Dec setting circle to get gouged).

They are tightening up the plugs on the Temma control box; one of the screws holding them in place had come loose.

They have not yet messed with the speeding RA drive nor the reticle. I told them that if they were sending the reticle to Japan to be fixed, it might as well get updated at the same time; the current reticle only has marks until 2015.

They are moving along with the maintenance, but it is unclear how long it will be before the mount is complete and on its way back to me.

Progress.