What is the sound of no relays clicking?

I tried some unguided tracking tonight and captured the data so I could see what’s up with my mount.

I had to find a star bright enough to calibrate but dim enough to guide on. Did the calibration routine, then set RA aggressiveness to 0 once everything settled.

This is the data I got out:
Tracking only data

There is a steady (negative, leftward, which I interpret as “Eastward”?) drift in RA that reached 10 pixels max, 7 pixels RMS over the course of 40 minutes.

This data should give some indication of the smoothness of the PE curve, but also I believe there’s some bad in there about the motor controller running too fast or too slow…

With the newly-tuned mount, I decided to try Pumpkin on some more unguided imaging. After the “baseline” from the previous night, I now wanted to see what this MFWB could really do.

M42 was a bit far west and covered with clouds by the time I got Pumpkin up and running (I had a pretty funny motor stall that wigged me out momentarily — in my haste to get imaging after testing Trixie, I had forgotten to swap out the counterweights, so 10# Pumpkin was offsetting 43# of counterweight… oops), so I decided to see if I could work The Rosette for a bit instead.

This time, I centered the cluster that I could see in the finder. This proved to be a good decision:

That’s 12 five min subframes, one hour of integration time. Rosette, you are mine.

I picked up some wispy outer nebulosity, too, that is easier to see in inverse:

Still a bit noisy. I’d like to apply a full calibration set on this, and have about 3 hours of integration time to work with.

This was shot under an 8-day moon.

The image is unguided.

With an hour of The Rosette in the can, I decided to switch to 20m subframes instead of 5m.

I only got 2 frames before the mount hit its safety limit.

I’m pretty sure this trailing is in Dec, indicative of a polar alignment error.

The new MFWB showed up yesterday, and I knew that I needed some time to work on it, so I did the installation during the day today. Here are some notes about the process.

Here’s what the original wormblock looked like.

I was installing the new worm block, ceramic bearings, a new gearbox for RA, and a replacement for the Oldham coupling.

As you can see, the stock Losmandy worm “block” is split into two individual parts, making adjustment tricky.

The motor has to come off in order to get at the gearbox.

The gearbox brings a piece of the Oldham coupling with it.

The Oldham coupling needs to come off in order to get the worm out of the blocks.

Here you can see my abortive attempt to “shim” the old worm blocks using stacked postage stamps.

Worm block plate cleared and ready for maintenance.

Now that I had the worm out, I installed it into the new worm block, along with the very nifty ceramic bearings.

This end of the block is “pushed in” a little so that the worm can be pre-loaded. It should be tight enough that the worm can’t wobble back and forth (left-to-right within the block), but spins freely (it sounds a lot like a rolerskate wheel in motion).

Here’s the wormblock all assembled, with bearings and worm in.

Now it’s ready to be installed, with a nice thick coat of white lithium grease.

Here’s the new wormblock in place on the mount, ready for adjustment. Note that the original Oldham coupling is in place. More on this later.

…time passes.

What I did next is to use two identical sets of feeler gauges and a rubber mallet to ensure that the gap between the worm block and the worm wheel housing is exactly the same at both ends of the wormblock.

Once the gaps are equal, I then turned the Oldham coupling (which has a convenient spot to put a screwdriver), and, thus, the worm, so that the mount rotated a full 360deg in both directions. I re-adjusted the gap and re-ran this test until I found the tightest gap where there was no binding at any point in the rotation.

This took several iterations, especially since it took me awhile to figure out how to properly apply the rubber mallet…

I finally settled on 0.045” as the proper gap, tightened down the block, and was ready to re-assemble!

I replaced the Oldham coupling with this new gizmo. The process is: put the new coupling onto the gearbox (I replaced the gearbox with a new one at this point), install the gearbox (hand-tighten only). Then gap between the worm block and the coupling to be even all the way around (I chose 0.002” at random). Tighten the grub screws on the wormblock side first, gapping each one. Then tighten the grub screws on the gearbox side. The “spring” should be pushing towards the gearbox when the install is complete.

That was the last of the fiddly adjustment. I installed the motors, and was ready to test!

I tested the mount powered up, slewing 360deg in each direction at 1200x sidereal, with no stalls. At 1600x, I got some stalls (entirely expected). I left the slew speed at 1200, goto at 800 for now.

I could not have done any of this without having my friend, the G-11 Jedi, explaining what I was up to. Thank you very, very much.

The internet is a wonderful thing.

It’s supposed to be clear tonight; then I can test.

I mounted up Pumpkin by herself tonight. The mount’s been having a problem with guiding, very rough behavior in RA. I’m going to be tuning the mount up tomorrow, but the sky was clear, so I decided to see if it behaved a little better with just one tiny little scope onboard.

Because I also don’t have an OAG at the moment (I’m picking it up tomorrow), this was an unguided test.

I started out, as is normal, with a shot at M42. The pointing model was a little rough, so the nebula is off-center. The mount was so far west by this point (and the clouds were rolling in and out so much) that I only got 2 frames of M42, so this is a fairly noisy 10min integration:

To emphasize some of the wispy nebular detail, I inverted the photo, also:

…nice. I do like these Astronomik Ha filters. This is with the clip-in.

Once M42 was too far west, I switched to The Rosette. I need to learn the star patterns around this object, because I thought I could see the star cluster off to the right in the finder scope, but I wasn’t sure, so…

Yep, another swing-and-a-miss. The Rosette is quickly taking on the Nemesis status that The North America Nebula had for so long. Flashes of brilliance on a cool looking nebula, but a lot of near misses. Oh well. This is a 30min integration.

Aww, how cute! Pumpkin as the “main imaging scope”:

The unguided behavior is better than things have been recently. But I’m looking forward to seeing whether the MFWB helps this any.

My new Martin Farmer Worm Block finally showed up tonight. It’s been in-transit from the UK for a week.

I’ve had nothing but good reports about this monolithic worm block from the G-11 group on Yahoo, so I’m looking forward to getting my mount all tuned up in RA tomorrow.

Here’s a photo of the newest addition to the observatory:

There was a brief moment between the stormfronts tonight, where I got to see a few stars and the really pretty crescent moon.

Then the clouds closed back in. It’s been raining cats and dogs for several days now, and has been cloudy for over a week.

No mail came today (MLK day), but I am expecting parts to show up for the mount any day now, at which point I can have some fun ripping things apart and installing new kit.

Clear Sky Clock said it would be cloudy all night, so of course it stayed 90% clear until about midnight, when it socked in. But I’m getting ahead of myself…

I decided to get the autoguider up and running tonight. I wanted everything focused and aligned so that I can get started shooting again for real.

On top of this desire, my new clip-in Ha filter showed up today, and I really wanted to try it out!

So I hooked up the autoguider, got it all focused and balanced the rig. I booted up the scope, which wanted to cold-start again. No problem. Quick slew to Betelgeuse… and that’s where the problems started.

For some reason, the main scope and its finder (which were aligned as recently as 2 days ago, and have not been touched) are no longer in alignment. No problem; I see the star in the finder, I’ll just sweep the scope around until I find it.

No dice.

I don’t know what my problem was, but I tried everything I could think of, including sweeping the scope by hand, and I could not find *anything*. It took me 40 minutes to finally stumble over Rigel and then get the finder and scope aligned. While that was in the vicinity, I set up the guide scope to be roughly aligned, too.

As part of this fun, I figured out that the reticle is not centered in the guiding eyepiece. Again. That is a silly feature. But I figured out how to get it centered, so now the guide finder, guide scope, and reticle eyepiece all agree about the center of the field. Which is nice.

So after losing about 45 minutes of clear sky, I got the scope turned on and started an alignment run… the deep cycle battery died. argh. OK, set up the 15v power supply — deal with the battery later. Now I’m working the alignment (oh, I had mis-calculated GMT earlier in the evening, too — I was having a bit of a day), and the polar alignment is way off compared to a few days ago. Pulled out the polar alignment scope illuminator, and it’s got a busted power cable. Again. That is the worst design ever. I decided to just go forward with it; I’ll deal with polar alignment later. I need to be using my Gizmo anyway. Where is that thing? hmm…

OK, so I’m aligned. I boot up the computer, and shoot a test image of Betelgeuse through the Ha filter. It is of course not in focus. No problem. Fire up FocusMax (nothing can go wrong with the focuser — it’s on COM1), and …

all of the FocusMax windows show up offscreen. I have no idea why. I even tried to Regedit them into place; no dice. Meanwhile, tick, tick, tick, clear sky still, but I can see clouds moving in. Also, Orion is now well past meridian. grr!

Fine. I fire up the focuser in MaxIM (I tried to get the ST-4 and mount working in MaxIM, too, but needed to reinstall the USB-to-Serial drivers for reasons passing understanding, and never got that working right — you guessed it, deal with it later), did an autofocus run in MaxIM for the first time ever.

Let me say at this point that I really like the new MaxIM focus routine. It brings up a V-curve just like FocusMax, and while it seems to converge on a solution a little more slowly, it does seem to get there pretty well, as evidenced by the fact that in just a few minutes, I had autofocused the Ha filter on Betelgeuse! (FWHM of ~5.5, high winds and encroaching clouds and sketchy collimation, so give me a break, this is about what I usually get)

So I fired a 40sec exposure of Betelgeuse, so I could see some diffraction spikes, and got a bright fuzzy ball with lots of stars in the background. I looked up, and couldn’t even see the star through the cloud cover. OK, I get it. So I slewed over to M42 anyway, because I was going to make sure I was in focus.

A couple of 40sec and then 2min frames of M42 looked pretty good given they were clearly destroyed by clouds.

I tried to set up the ST-4, but it spent a lot of time losing the star and giving me “E E” followed by “-E -E” type corrections, so I turned it off. I only like guiding in MaxIM if I can help it.

At this point, it was about midnight, and we get to where I started this post… socked in solid with clouds, and no images to show for it.

And a longer todo list.

But a few more things are set up again, including of all things, the autofocus routine in MaxIM! Cool.

Fingers crossed for a clear night this weekend. Next one won’t be wasted.

Given my strange “bell-curve” style tracking errors that I was getting last spring/summer, I am unconvinced that my mount is the source of the problem. I need to find and kill the flexure problem first, then I can worry about the mount again.

Having said that, I have several updates/upgrades/fixes to do to the mount:
- remove DSCH encoders and replace with spacers
- replace RA gearbox with the one Art sent
- replace RA bearings with the ones Art sent
- make decisions about which worms to use where (I have 3 precision steel worms, and 1 brass one)

Once all that is in or not, I can decide if there is anything else I need to do to the mount, in particular:
- Ovision or MWB worm/worm block (or blocks)
- Maxxon motors

- Gemini firmware upgrade

I have a sneaking suspicion that my setup is actually pretty good. I just need to take everything to the next level in order to deal with the longer exposures I can get out of the narrowband rig.

After 10 days of fighting Veronica, I’d had enough. Tonight, I swapped the camera back to Pumpkin, rebalanced, and tried my luck at two targets.

With Cassiopeia showing above the house, I decided that I wanted to try for IC 1805 and IC 1848, The “Heart” and “Soul” Nebulae that lie between Cassiopeia and Perseus. Note that it’s July, not October. But, since Pumpkin seems to do pretty well (owing in no small part to the 5”/px and huge FOV and huge guidescope), and since I like to avoid running the scope into the pier, I find that I choose objects that are “a little low” and let them rise all night.

But these guys were still below my “horizon” (read: The wall of the observatory ) yet, so I needed to shoot something else for an hour or so, until Cassiopeia rose a little bit.

So, I decided to continue my widefield survey of Cygnus/Cepheus, and did an hour (back to 20m subframes — I love that li’l orange scope!) on Sh2-119.

The Sharpless nebulae are opening whole new vistas in my target list, and I’m *really* enjoying going after these objects in full knowledge that I’d probably get nothing but noise and pain if I tried this without the Ha filter.

Sh2-119 in Cygnus

I like Cygnus. It’s really good to have Pumpkin back. I have nothing more to say about this object.

Now it was late enough that I could start getting some time on Cassiopeia. Some clouds threatened to roll in, ate my guidestar for awhile, etc. Pumpkin just powered through all that. I only lost one frame out of 13 (to clouds). Since IC 1805 was laid in “horizontally”, I missed the nearby IC 1848. That’s for tomorrow night. This is a full 4 hours of Ha from Pumpkin on an object that I have no right to be shooting for another few months.

IC 1805 The Heart Nebula in Cassiopeia

In a word, Wow. I’m back on track again. I am having fun with my widefield shots in a way that I haven’t been having fun for awhile now. I want to buy an OIII filter and go back and shoot all this stuff again. I am giddy when I see the cool stuff show up in each subframe.

The guiding is a little rough. But the results speak for themselves. I am ready to shoot my way through the rest of the month. Yay!