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 polar alignment scope in my NJP has never been accurate. It’s been off since I got the mount, and there are a couple of other things that I wonder about, too; in particular, I think the mount was mishandled during shipping at one point, and it threw some stuff off.

The problem is that the polar scope is literally built into the RA axis of the mount. It is not a “user serviceable” part in any way.

All of the repair work for Takahashi mounts in the US goes through Takahashi America, which is in Texas. I talked to the guys in TX about the mount, and they are convinced that there is a problem with the polar scope. They need me to send them the mount (which weighs 65#; I’ll need a very strong box to ship it).

Then they are going to test it, and when they find that it’s broken in the way that I have told them, they are going to take the offending part out (by which I mean the entire RA axis core), ship it to Japan, and have the team at the Takahashi mother ship fix it.

The fixed part will get shipped back to TX, who will ship it back to me.

Luckily, the part that gets sent to Japan is not the whole mount; the RA axis is made of machined brass, but it probably only weigh 5 or 8 pounds.

But, the Japan drop has to be via airmail or else it will take forever.

And I get to pay for bench time in both Japan and TX.

I’d have thought that Japan would have to pay shipping on it though; I feel that it’s a manufacturing problem. However, the manufacturer’s warranty: a) only covers the original owner (which is completely screwed, if you ask me), and b) is 5 years (the mount is a 2004, which I got in 2010, so…)

Why send it to Japan? The problem is that you need an optical bench to fix the reticle in the polar scope (I assume that it’s a misaligned reticle, and not a bent RA axis), and apparently TX doesn’t have one. So I send it to them, they dismantle it to get to the part that needs fixing, and send that to JP.

It will probably be about $100 round trip to get it to TX,
another $100 round trip for the lighter part to get airmailed to JP,
plus a $200 or so in bench time for the TX guys to teardown and rebuild and the JP guys to adjust.

This assumes that there’s no actual parts involved.

So anyway, if I budget $500 I will probably be close.

It’s a lot (more than I spent on my first mount, total, in fact). But a fully tweaked out and working NJP is definitely worth it. Even in its partly-broken state, 04026 shines as an astronomy platform. I hope to own this mount for years to come. So this is an investment in my future.

This has been a problem with the mount since I got it, so I have been saving up money in my astronomy account for the day I had to ship the mount to Texas. If I hadn’t built the CNC machine last summer, I would have done it then. Anyway, I just have to scrape together enough to get it shipped to TX and then continue saving until I can afford to get it back from them.

It’s probably going to take 6 weeks or so to get the mount back from the time I ship it, so that’s not a big deal.

Time to find a box. A strong one. And lots of packing material.

Hang in there 04026. The doctor’s on the way.

After getting the mount “close” last night but then moving the pier topper and redoing, I took a couple of runs at polar alignment tonight, too.
One thing I definitely learned is that my polar scope is misaligned in some way. Put the star on the “2010″ hash mark, run the mount in RA, and the star drifts up to 1985 and down past 2015. Maybe there’s a way to fix that without sending the mount in for repair. Maybe I’ll just ignore the polar scope for awhile…

I spent a lot of time thrashing in WCS. I seem to remember that when I was doing this with the G-11, I ended up writing down each correction I did.

I figured out that I had 2 settings incorrect. First, I had “RA star” set to “in the north” instead of “in the south”. grr. Also, much more important, I figured out that I have to set “Inverted” corrections when running on Veronica. I kept doing Elevation changes and getting back larger errors. Once I set “invert”, it converged within 3 iterations.

The mount is now at (according to my feeble understanding of WCS) about +90 in azimuth, and about -70 in elevation. I’m not sure what units the “correction factor” numbers are in WCS, but I think this is pretty close.

Before I shut down for the night, I’ll give the polar scope one last peek. But I am certain that the star won’t be “where it’s supposed to”.

I think I can get the polar alignment to a “no correction” in each axis, rather than a “really small correction”. ~90 is correctable. ~70 somewhat less so. I am shooting for <40. One more set of iterations tomorrow, then some more unguided testing. I need to recall which way is “north” in the camera, also.

ad Astra Observatory is back online.

With the newly-leveled mount, I worked the polar alignment some more. It still needs tweaking, but once I gave up on PemPro (which has never really worked all that well as a polar alignment tool for me) and switched to WCS (which has worked splendidly), things went more smoothly. There’s still something strange about the slewing direction, but I’ll figure that out later.

I decided to grab some autoguider data in MaxIM. After some initial thrashing about aggressiveness and delay between corrections, the mount settled in nicely to an RMS around 0.19, or 1.1″ (peak to peak!). I gathered data for a good long time, and analyzed for PE:

There are no words. “Um, wow” doesn’t even begin to cover it.
I love this mount. I don’t care if I can’t run any other telescope. If I can only do this with Pumpkin, I will gladly shoot the whole sky at 400mm in every wavelength of light I can think of. Are you kidding me?!

Here’s the photo I pulled out. It’s just 3m subframes, because the skyglow eats images longer than that. 3m guided subframes from Pumpkin is not shocking. But, here it is anyway.

The mount needs tweaking; a saddle. Someplace to hang the hand controller. Some strangeness about which way is up.

And of course it remains to be seen whether this tracking will hold up at 2350mm (or even 1000). And for 20 minute subframes. And… well, the sky’s the limit.

But, in short, so far, so good.

sic itur ad astra “thus shall you go to the stars”, indeed.

Polar alignment still sucks.

Once I get the mount aligned, everything will be fine. Until then, it’s a bunch of hooey.

I need to get the mount level, because, as usual, it’s causing me no end of grief.

My assumptions about polar alignment haven’t changed with the lessons I learned tonight:
1) Once you nail the elevation setting, the azimuth is very easy to set.
2) If the mount isn’t level, you can get close, but not nearly close enough to do any useful imaging.
3) Polar scopes are great for visual work, but for imaging, you still need to get closer. Corollary: see 1). I think that a polar scope could get you *real* close if you were 100% sure about your elevation setting. More on this later.
4) Good polar alignment software is like a good mechanic — if you find one you like, hang onto it.
5) If you dial in azimuth, then dial in elevation, and you find that azimuth has changed significantly, quit messing with the axes and get the mount level. You are officially wasting time if you don’t.

I have never had a good gut feeling about polar scopes. I admit that the Takahashi one made me feel like I was really doing something. And I admit that for visual use, once I used the polar scope, I was ready to roll for the night. And I know from past experience that once you get a really solid polar alignment once, future alignments at the same site are way easier. Because then the problem is constrained to a single mount axis, and so the push-me, pull-you interaction between the axes is totally gone. It’s getting that first alignment nailed that’s key.

I might even take the mount off of the pier and polar align it from the tripod to start. Then I don’t have to worry about “is it level?”. There’s work to be done on the alignment. It always goes like this. I spend a couple of nights and a bit of a day working on the alignment, and then it’s all gravy once I get it dialed in.

While the software was gathering alignment information in Dec, I had a hint of how the RA tracking on the mount works. I got no feeling for magnitude. But wow, it sure looks pretty smooth. I didn’t see any jumps as large as 1″. Tantalizing.

I spent the night polar aligning the NJP.
Man, I love the sound of the mount as it slews. It’s… hard to describe.

The polar scope (and its attendant app) got me close enough for visual work, but when I started running unguided images of varying lengths, I noted that I was getting a *lot* of drift in Dec.

So I pulled up PemPro (my trial still has 13 days left on it), and started a software polar alignment routine. PemPro’s routine is slick, but I don’t know that it’s worth $150, given that I can’t use many of the other features.

I will have to find a polar alignment program. I’ll get to that later.

The strange thing is that I hooked up several programs (PemPro, MaxIM, and Cartes du Ciel) to the Temma all at once via ASCOM, and things got really confused. In particular, someone in the setup has north and south switched. I will hold down the “north” button on the hand controller, and watch as the scope points poleward, and in the planetarium program, the pointer is moving south. Also, I keep needing to set Dec to “-30″ in order to get the scope to point to +30 Dec.

Something that needs figuring out. I don’t know where the mistake is, but I’ll find it.

Good news is that the slews were working well. I dropped several clusters right in the FOV, with a single star alignment. Nice.

I had a bunch of maintenance piling up in the obvservatory, so I decided to do some of it since it’s raining all weekend.

I spent a little time getting the mount more level, and adjusting the elevation on the polar alignment. I still don’t think it’s perfect, but I think I’m closer.

The polar alignment still needs adjustment in azimuth, and a final check in elevation.

I installed the new EEPROM (v1.04; apparently 1.05 is only from Goerlich) and a new battery in the mount. I also hooked up the GPS and got the time and location correct.

I mounted up the new autoguider and tried to take a couple of daytime shots to test it out, but the observatory computer fried, so I spent the time to rebuild the observatory machine from the ground up. That took longer than I expected, but I think it’s up and running now. I was having an awful time trying to get VNC to work properly. It was running really slowly on a fresh install of Win XP SP3. After much gnashing of teeth and tearing of hair, I rebooted all the elements of the LAN (modem, router, etc), tweaked the firewall on the new machine, and installed several Windows and Dell updates. Something in there “clicked”, and now it’s up again and fast as ever.

I took the C9.25 to a local park and set up the artificial star about 75yd away. That was more than enough to get me in focus, and with a few tweaks of the collimation knobs, I saw, for the first time, *perfect* Airy disks! I was collimating at 700x, so gorgeous. The C9.25 is ready for… something. It’s back in its (new) case for now, but ready to rock.

Buoyed by that success, I decided to try to collimate Veronica, too. This was not as successful. I will have to read up on collimation, because the closest I could get to Airy disks was seeing little tiny “crosses” (even on the dimmest light), which merged “vertical” if I went one way out of focus, and “horizontal” if I went the other way. There is a ton of light being thrown off outside of the 4 main diffraction spikes, too. I think I’m closer, but I will be using the C9.25 or Pumpkin to do polar alignment and pointing models for awhile…

A very productive weekend, despite only having 90 minutes of clear sky.

As near as I can tell, the mount is within 1 degree of being level. It’s probably within half a degree, but I’m being conservative.

That small error, probably a quarter turn of one of the pier levelling bolts, makes my polar alignment routine pure hell.

I decided tonight to “bounce back and forth” between alt and az, to see if I could head off the “dependency” between the axes that is introduced when the mount is not level.

I have been iterating for nearly 4 hours, and have overshot on each axis twice.

This is madness.

Well, I think I finally nailed the polar alignment.

A: 1 E: -1

Here are the rest of the modeling parameters:
dH 26′
dD -2′
NE 33′ (Axis non-perpendicularity at the equator)
NP -7′ (Axis non-perpendicularity at the pole)
IH -35′ (Index error in hour angle)
ID -3′ (Index error in declination)
CF -3′ (Counterweight flexure)
FR 44′ (Mirror flop/Gear play in RA)
FD -0′ (Mirror flop/Gear play in Dec)

I looked up the definitions for all this, but I’m not entirely certain what it means, or how normal any of these numbers are.