Tech – Mounting the Renishaw Encoder Rings (Part 1)

Beside the work on the Kepler Remote Observatory building this fall, we also work on getting the telescope assembled again. One critical milestone for this are the absolute encoders and their mounting on the fork mount.

One of the main problems was to decide on the correct material for the parts. For several reasons and for convenience we decided to go with stainless steel.

We now got the first blank parts, which are now handed over to our partner for turning and milling the actual parts.


A still open point are the friction wheels. They are made out of a much harder stainless steel — we still wait for the blanks for the friction wheels.

Once we have all parts milled and turned we will start rebuilding the telescope (already with the absolute encoders). We plan to have a first test run of the telescope this winter (but not at the actual Kepler Remote Observatory)

So stay tuned for more news regarding the telescope and its rebuilding process.


Under Construction – Securing the Dome from Snow

Last winter we observed that our dome is prone to let a lot of very fine snow particles inside. We observed some severe snow inside the dome, as you can see on the following picture.

Severe very fine snow inside the dome. Captured with the internal IR-Cam on 16.01.2019 (Photo by the Kepler Remote Observatory security system)

So we decided to update the dome with some special “snow deflecting systems”. One of the additions was mounted this fall (before it starts snowing again on 1100m above sea level).

After some examination of the dome, we came to the conclusion that the rather big gap between the dome and the building itself, is one of the main issues. Since this gap is necessary to let the dome rotate freely, we needed a special solution.

In our case, we think, a flexible cover over the gap will do the job. It will let the dome still freely rotate but otherwise cover the gap, so that the fine snow particles cannot enter the dome via the gap. We also installed a brush ring to hinder the snow from entering even more.

The first thing we had to do, was to install a metal mounting ring to get a stable foundation for the brush ring.

The metal mounting ring with cut-outs to follow the curvature of the dome. (Photo by Johannes Stübler, 15.10.2019)
The metal mounting ring already installed and the brush ring installed too. (Photo by Johannes Stübler, 15.10.2019)

The actual flexible cover, will be mounted on the gray curved part of the rotating dome (you can see it in the above picture directly above the metal mounting ring). Actually this fiber glass part is the source of the problem → it is way too small. It covers the gap just barely.

The additional flexible cover is a black natural rubber band. This rubber band will extend the fiber glass part about 30cm and thus will make the gap hard to pass for the snow — especially with the additional brush ring which makes it even harder for the snow.

The final rubber band covering the gap between the rotating dome and the building. (Photo by Johannes Stübler, 22.10.2019)
Before the installation of the natural rubber band with the metal mounting ring already installed. (Photo by Johannes Stübler, 15.10.2019)
Finally with the installed natural rubber band. (Photo by Johannes Stübler, 15.10.2019)

So finally the snow can arrive at the location. We are now very curious how this modification of the dome holds up against the harsh winters up there.

There are still some things to do at the Kepler Remote Observatory before the winter really hits:

  • Installing better surveillance cameras inside the dome to be able to track if and how much snow will still enter the dome
  • Installing an all sky cam
  • some local server work we can’t do remotely

Aside the Kepler Remote Observatory building, we are also working on the telescope:

  • We now got the material for the absolute encoder ring mountings → therefore we started with the manufacturing of the mounting parts (read more in the future)
  • We are also working on the motorized main mirror and corrector covers
  • We plan a test of the telescope already this winter (although not on the actual Kepler Remote Observatory)

I know it was quite a long time since our last update, but be sure, we are working hard on the project. It is just not always time to write something in the blog.

But stay tuned for further hopefully interesting stories regarding the construction of our remote observatory in the Alps.

Star Park Hohe Dirn: Public viewing

On the weekend from Saturday 26th October to Sunday 27th we had a public viewing event, held by our partners the Sternfreunde Steyr. Due to the quite good weather conditions a lot of visitors showed up at the Star Park in 1100m. Also two colleagues with their quite impressive 20″ and 22″ Dobson-Telescopes where present – you can imagine what a great view we had.

We watched for example the western Veil Nebula (NGC 6960), the Crab Nebula (Messier 1), or the Horsehead Nebula an alot of other objects in a staggering detail.

The visitors (>50) where quite impressed from the “Star Party” and asked a lot of questions regarding the objects we watched, the Star Park and of course the Kepler Remote Observatory project. We happily answered all of them.

Now have a look at some of the impressions caught during the night by our colleagues.

One of the two big Dobson telescopes (22″, f/4.8, GoTo). (Photo by Johannes Stübler, 26.10.2019)
The second big Dobson telescope (20″, f/5, GoTo). (Photo by Johannes Stübler, 26.10.2019)
The sky above the Kepler Remote Observatory. In the foreground a small photographic setup on our new external post. (Photo by Johannes Stübler, 26.10.2019)
The “Window to the stars” of the Kepler Remote Observatory. (Photo by Johannes Stübler, 26.10.2019)
The “Window to the stars” of the Kepler Remote Observatory. (Photo by Johannes Stübler, 26.10.2019)
The Milky Way above the Kepler Remote Observatory. (Photo by Johannes Stübler, 26.10.2019)
Star trails above the Star Park Hohe Dirn. (Photo by Johannes Stübler, 26.10.2019)
Star trails above the Star Park Hohe Dirn. (Photo by Johannes Stübler, 26.10.2019)
Star trails above the Kepler Remote Observatory. (Photo by Johannes Stübler, 26.10.2019)

We also installed an All Sky Cam this day and updated the external surveillance cameras (external dome surveillance) since one of them was quite crap.

More about the All Sky Cam in a future post. So stay tuned for an update on this.

We also installed the internal dome surveillance cameras which are used to check the dome and the installed telescope during operation.

Tech – Server

Finally our command and control servers for the telescope arrived. Now we can port the already set up and tested environment from a desktop PC to a “real” Server. This added a lot of headroom for the virtualization of our productive environment.

The next task is the conversion from our virtualized Windows only command solution using ASCOM to a virtualized Linux only solution using INDI. The past showed that ASCOM is not up for the task handling such a project.

The first task of these new servers would be running the surveillance cameras and providing us some real time insights into the dome and the observatory surroundings during the next winter – this will help us to harden the dome against moisture and snow intrusion.

Some pictures from us setting up the servers.

(Photo by Günther Truhlar, 02.07.2019)


Under Construction – Electrics (Part 3)

After the rather strong winter at our observatory site, the weather got fine and we could continue with the electrical work at the observatory.

Some finalization of the electrical wiring and mounting of some surveillance cams were open from previous year.

So we meet at the observatory on 23.06.2019 and finished the work.

We also reinstalled the renewed working desk. So finally we have a desk – chairs are still missing 😉 …

Here are some photos of the construction work ongoing. 

And an impression of the location of that day.

(Photo by Günther Truhlar, 23.06.2019)

Project presentation at the 22. Minor Planet Conference

This years German minor planet conference (German) organized by the VdS-Fachgruppe „Kleine Planeten“ (German) in Salzburg at the Vega Observatory (German) was also a chance for us to present the project to a professional audience.

The project was very well received and some cooperation may arise from this meeting.

(Photo by David Voglsam, 16.06.2019)
(Photo by David Voglsam, 16.06.2019)

Tech – Reassembling the Telescope (Part 1)

After we got the telescope body back from sandblasting and painting (read here what happend) we were ready for the first test fit. We need to find out the margins we have to add the absolute encoders and their mounting mechanic.

We also measured out the dimensions of the ball bearings we need to mount the encoders.

(Photo by Günther Truhlar, May 2019)

After the measuring was done we disassambled the telescop again to prepare it for mounting the encoders. Therefore we have to wait for the delivery of the ball bearings and some metal parts.

Once we received all parts we assamble the whole telescope and bring it back to its original loaction in Davidschalg for testing. When all works fine, the installation of the telescope at the Kepler Remote Observatory site in the Star Park Hohe Dirn is planned for next year.