Replacing the focuser on the RH200

First, I need to replace that stock focuser of the RH200 with the FLI Atlas focuser (even Officina Stellare recommends to use the Atlas over their own focuser ...)

Here is the scope before doing anything:

First, we have to remove the four tip-tilt screws:

To take of the entire backplate with the focuser attached:

Then remove the four screws on the inside that hold the focuser in place:

I struggled to remove the long screw that the focuser is running up and down on:

... until I realized that it had a tiny set screw on the focuser knob that had to be loosened first:

Now it was easy to remove the whole focuser

Attach the focuser to the plate and put the whole plate back on:

And finally attach the Atlas focuser:

Yei!!!

A Officina Stellare RH200 Veloce!!!

I was so excited about receiving this scope that I forgot to take any photos about unpacking it or such... Can't wait to try it out. Though it will take a while:

• First, I need to install the Atlas Focuser
• Collimate the primary mirror and front plate (if necessary)
• Align the imaging train to be absolutely straight

Wrong mount detected in firmware

... and after all these days, I just realized that my firmware / keypad thinks that my mount is a GM 2000HPS (not 1000)!!! I looked into the keypad settings but didn't find any place to set this - I also looked if there is a way to reset the firmware to factory defaults - but that also doesn't seem to be possible.

Upon further investigation, the wrong mount is also displayed in the ASCOM driver and the MGBox software.

At this point, I contacted Tolga (from Tolga Astro where I bought my mount) and asked for help.

Update December 4th:
The support from 10Micron contacted me and asked to send in a log file from their mount logger app (I love it if companies have good logging software that you can run and they can use for further diagnosis). They also wanted to see a photo of the control box of the mount:

... this one also says GM1000!!! :-(

10Micron sent me a "Mount Remote" app that I can use to connect to the mount and they can use it to diagnose it from the distance. Very cool. Installation was almost straight forward. Initially the vcruntime140.dll was missing, but I could download and install this from Microsoft. Now, I'm waiting for 10Micron to connect and hopefully find out what's wrong.

Update December 5th:
The engineers at 10Micron analyzed my mount and determined that at some point a configuration file was corrupted during shutdown. Which isn't a problem as they get restored automatically. Only that the program restored the wrong configuration file (for a 2000HPS mount). So, now everything should work again. Yei!!!

Incomplete Slews with the 10MIcron mount

When using the 10Micron mount, I noticed that slews seem to be very inaccurate (with or without a model or alignment). Upon further analysis, it turns out that all slews are incomplete.

E.g. starting the mount from it's park position (RA 1h20min, DEC 89° 32') to Neptune (RA 22h 53min, DEC -8° 6')

	RA	DEC
Park	1h 20min	89° 32'
1. Slew	23h 42min	25° 54'
2. Slew	23h 11min	3° 55'
3. Slew	23h 1min	-3° 34'
4. Slew	22h 57min	-6° 11'
5. Slew	22h 54min	-7° 37'
...
Neptune	22h 53min	-8° 6'

I.e. the mount gets closer (each time about 66%) but never reaches. Initially I thought that this would be some timeout issue, but then the mount would slew the same amount each time. But that's not the case. This happens when using the keypad, the virtual keypad, software (TSX or SGPro) or through the API (e.g. from ModelCreator). It also happens both with the 12V power supply and the 110V power supply.

No idea what this is - and I also asked on the 10Micron forum.

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Update: It turned out to be caused by the other problem that I had (that the control box thought my mount is a GM 2000HPS). Once that was fixed, this issue was gone. Yei!

New Mount: 10Micron GM1000 - First time out

With everything in place, I could finally take the mount out for the first time!!!

First, I wanted to try out the rough polar alignment with the green laser pointer on the scope. But either the laser is broken or WAY too weak, but I could not see a beam at all :-( So, scrap that idea.

Now, rough polar alignment turned out to be tricky. The 10Micron mount uses simple star alignments for polar alignment (3 stars for a rough alignment, a full model for exact polar alignment). But when the mount is not even nearly polar aligned these are difficult through a camera as the I can't use "Closed Loop Slew" in TSX or plate solving as the it is WAY too far off.

So, as I want to use the mount unguided anyway, I decided to remove my good, old Borg scope + Lodestar guider and replace it with a simple red dot finder:

Another nice side-effect of this is that there WAY less weight on the scope now. I could move my counterweights significantly up - maybe I can even get rid of the smaller one completely!!!

With a rough polar alignment, I tried various of the 10Micron functions:

1. Balance check
I really like that they put this into the functionality of the keypad. The mount moves the scope into specific positions and measures on both sides if any creates more or less friction. Measuring in RA was quick and showed that I was only 0.01% off (everything below 0.04% is considered enough for good, stable imaging).
For the DEC measurement, the tripod became an issue. As the mount is pointed almost straight to the side and moves the scope all the way from one side to the other, my filter wheel collided with the tripod and stopped the whole procedure:

This is another reason why I like the AP Eagle pier (the other one being that it has better possibilities to fix all the boxes).

The good news is that there is a dialog box asking for confirmation before slewing to the other point. At that moment, I can slew the scope further upwards and then it passes. But I should really try to get an adapter from the Eagle pier to the 10Micron mount. For now, I'll probably move the filter wheel around and point it upwards.

2. Orthogonality (cone error)
From the various alignment points, the mount calculates the orthoganility error. In my case it was 0!!!

3. Polar alignment
Now, the polar alignment was fairly easy. Select it in the keypad and do the usual azimuth/altitude adjustment to center the star.
While doing the alignment, I noticed two things:

• to adjust the mount in Azimuth, the four screws that fix the mount to the tripod have to be loosened. And of course, I have to remember to fix them again afterwards.
• the Altitude know has a significant amount of backlash (see above). It's not getting too much in the way of adjusting the mount, but it is weird that it is SOOOO much. Asked in the 10Micron forum about this.

But now, my mount is polar aligned.

4. Tracking precision

Without guiding, I measured the precision of the mount as-is (i.e. no model or such): << 1" !!! That's a pretty awesome precision!!!

5. Configuring in SGPro

The main difference in SGPro configuration was to switch from PHD2 guiding to "Direct Mount Guider". This basically doesn't do any guiding, but still does Meridian Flips and Dithering.

The other thing I wanted to configure is to not track too close to the Meridian to avoid that the filter wheel collides with the tripod. I measured that filter wheel collides roughly, when the scope is 5' away from the zenith. In SGPro, I can use negative values in the Meridian Flip settings dialog to indicate this:

... and then it got too late to really try it out ...

New Mount: 10Micron GM1000 - ASCOM driver

Apparently, the ASCOM driver situation for 10Micron mounts is a little tricky. There are two drivers:

1. The official driver from 10Micron. It can be downloaded from the 10Micron forum software section.
2. A driver from Per Frejvall. Apparently this driver was always more feature complete and preferred by many. But sadly, Per passed away last year and since then the driver is unsupported. Though it can still be download, e.g. here.

After reading a lot and also trying both, here are the main differences:

• Only the 10Micron driver will be maintained and extended going forwards.
• The 10Micron driver allows the mount to be connected via LAN or Serial cable - Per's driver supports only LAN. For me, the LAN connection is actually not to tricky as I have a LAN switch with scopes anyway. I can just plug it in there, give the mount an IP address on the subnet (192.168.86) and everything works.
  The only concern I have with the LAN connection is latency. I am constantly running Remote Desktop sessions to the NUC's on the telescopes and they often up- / download files to/from Google Drive. Not sure if and how much latency that adds. Just for slewing it's probably OK. But if I want to actively guide, then I'd rather not have any delays.
• The main feature that Per's driver has is to constantly upload refraction parameters to the mount for higher tracking/slewing accuracy. Although the latest version of the 10Micron driver seems to have a similar feature. Not sure if it is the same or not...

For now, I'll go with the 10Micron driver as it will be supported and developed in the future. But, again, if there are any real advantages I could switch to the other driver.

New Mount: 10Micron GM1000 - Cables and boxes

One of the disadvantages of the 10Micron mount is that it doesn't have any through-the-mount-cabling. I.e. I will have to find a way to guide the cables on the outside. Another disadvantage is that the Aries Tripod doesn't have any good points to fix all the boxes:

• The control box of the mount
• The keypad
• The MGBox
• The NUC computre
• The Anderson Powerpole
• The DC/DC converter

The cntrol box and keypad hang loosely from the azimuth lock screws on the mount:

For now, I put all the other boxes on the "tarp" that the Aries tripod has:

Not pretty, but OK for now...

The bigger problem were the cables from the mount: the USB cable, the 12V power cable and the power cable for the FLI camera. I want to maintain what I had before: that I can disconnect them easily, remove the scope and reconnect them.

The 10Micron saddle has the lock screws for the dovetail on the left side of the scope - unlike the AP or Bisque saddles that have them on the right side. So, I move the cables over to the right side so that they don't get in the way of mounting and unmounting the scope. I sheathed them all the way down. Then I attached non-fixed cable rings on the saddle plate and on the  mount itself. I routed the cables through it and added velcro at the ends so that the cables create a large loop to have enough room to move the mount around. Plus because the cables are not fixed they can be pulled through if needed.

Not quite as nice as through-the-mount-cabling, but almost as good.

The 10Micron mount runs on 24V but came with a 12V-24V converter. I replaced the cigarette light plug with Anderson poles and plugged it into the powerpole distributor.

One final thing I did was to move my DC/DC converter in front of all equipment (not just the FLI camera). I measured the Ampere of both and there wasn't any real difference. Now, the whole mount is powered with smooth 12V power - even from a battery. I could now actually power the FLI camera through the powerpole distributer on the scope and have only two cables running down. But I'll do that later - once I am convinced that this works really well.

New Mount: 10Micron GM1000 - MGBox

For location accuracy and also to get data necessary for using the pointing model (temperature, refraction parameters) I bought an MGBox with the mount. It's a nice, small box that connects to the mount (via an RJ-45 cable) to provide data and/or to the computer (via USB).

I first tried it out with the computer through the program that came with it:

As the software auto-detects on which ports it runs, there aren't really any settings:

One change can be made after the ASCOM driver is installed: connect through ASCOM and not directly. This will allow to connect from multiple sources simultaneously. After a few minutes, you can see the measured parameters:

In order to run it with a 10Micron mount, one needs to install a special firmware that you download from the astromi.ch website.

After downloading it, you install it through setup dialog.

Now, when restarting the MGBox and the mount it looks like this:

(notice the Mount Model and Firmware info)

The next part I found VERY confusing! The MGBox manual says "Configure the Mount’s GPS-Port to be a serial port. Details about this can be found in the 10Micron Manual." But the 10Micron instructions say to "GPS-Port needs to be set to "GPS", and "Use GPS Data ON"...

So, which setting is it? Serial or GPS? I tried both and there wasn't any real difference. Nothing on the MGBox program changed (still shows model and firmware version), nothing on the keypad of the mount changed (still seems to show the same location information).

I asked on the 10Micron forum about this and apparently, the 10Micron instructions are correct: you have to set it to GPS. After closer inspection, I could actually see that the MGBox would overwrite the location data on boot, but the location string ("San Jose" or "Custom" or such) won't be overwritten.

So, "GPS" it is.

Now, my mounts location is update on startup, the time is set super accurately through GPS and while using it, the software and mount will have access to refraction data and such. E.g. using it as an environmental device in SGPro:

New Mount: 10Micron GM1000 - Initial Setup

I finally bought the bullet and bought a new mount: a GM1000 from 10Micron! The main reason were the absolute encoders (yei! No more PEC!!!) and that it has a built-in model building and correction algorithm.

The whole package came on a gigantic pallette:

... but it was a lot of stuff:

the mount itself	the counterweights	cables and instructions
cover and power supplies (110V and 12V)	Aries Tripod	Transport Boxes

Assembly was fairly straight forward: mount on tripod, counterweight shaft, counterweights, scope:

Slewed a little around and everything seems to work. Yei

First Light with Patricia

At the Oregon Star Party, Renate was so excited about the dark skies and what you can see that she saved all her money (and even had a cookie sale) for a 10" Dobsonian Telescope. 

Two weeks ago, it arrived and Renate called it "Patricia".

And last night it was just clear enough to catch first light: the Moon, the Pleiades and classifying several stars by color. She was so excited (and, yes, me too!)

Merging multiple images

By accident I shot various images of SH2-112 and SH2-115:

Both nebulae:	SH2-112 only	SH2-115 only

I was wondering about ways to combine these:

1. Treating them as a mosaic, i.e. preprocess separately and then combine (using Average - not Overlay in GradientMergeMosaic!!!)
2. Preprocessing them combined

The first one was fairly straight-forward. I preprocessed them as I always do and then used the GradientMergeMosaic process in Pixinsight.

For the second one, I did the following:

1. weighted them together
2. calibrated them separately
3. registered them to one of the images that has both nebulae
4. stacked them together

Here is the outcome of both processes:

Mosaic	Preprocessed combined

Well, that's pretty clear ...

But I still wanted to find out if the stacking of all images improved the quality of the image. So, I cut out SH2-115 from both images and compared those:

SH2-15 in mosaic	SH2-115 in combined image

Interestingly enough, the mosaic image seems to have a slightly higher SNR. So, I'll go with that method.

Proper Reducer for TOA-130 scope

So, now where I know that the Super Reducer won't work for me, I was looking for others. I found quite the plethora of reducers:

Number	Focal Ratio	Image Circle	Backfocus	Price
TKA31580	f5.4	44mm		$719
TKA31580L*	f5.8	65mm	106.2mm	$3000
TKA31580S	f5.8			$745
TKA32580A	f/5.4	44mm		$1190
TOA130R	f/5.76			$719

Apart from the various adapters that I need which one to choose??? Asked on the Uncensored Takahashi mailing list.

* This is the Super Reducer that I tried ...

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Most people pointed to the TKA3250A reducer. This is its spot diagram:

Not quite as good as the .67 flattener but WAY better than the 645 reducer.

Takahashi Super Reducer - again ...

I never received an answer from Takahashi America on my problems with the Super Reducer. So, I sent an email to Takahashi Europe to ask for help.

I received an answer almost right away!!!

The advice was to focus not in the middle of the image but 1/3 on the outside as sketched on this image:

I didn't really know how to achieve this (neither TSX nor SGPro allow to focus "off center")

So, instead I focused as normal and then move the focuser in and out within the critical focus zone (and a little beyond) to see if the curvature changes.

The critical focus zone of the TOA-130 with the Super Reducer is 170 microns. The step size of the FLI Atlas focuser is 0.085 micron / step. I.e. I need to move the focuser 2000+ steps to go in and out of the critical focus zone.

Unfortunately, this didn't make large (enough) difference. The curvature was always between 17 and 22 degree. But never significantly better...

---

The answer from Takahashi Europe was somewhat disappointing:

"The field is flat with the 67FL.
The field is slightly curved with the SRD645."

Here are the spot diagrams for both:

.67 Flattener	645 Reducer

I guess that means that this reducer doesn't work - at least for me ...