DDM160_user

Hello Luis, Many thanks for the invitation! Last March, I saw the group of 40 observatories from the road up to Montsec, - very impressive. My family and I stayed at the hotel near the observatories (Mmm, excellent cuisine :-). I hope to visit again soon, perhaps in the autumn. Yes, I will contact you. Thanks again. Cheers, Robert

Yes this is an excellent image. I visited Áger and the Montsec Astronomical Observatory in March last year. Áger is a beautiful village with a very dark sky. I wish my telescope was located there! - Robert

Tack så mycket! The flat-field corrector at prime focus is already in place, and the corrector for the Cassegrain focus will arrive shortly from ASA. The final milestone is the figuring and alumizing of the primary and secondary mirrors. That is a big milestone. Will I finish the optics this year? Hmm…I was sure I could finish them last year, but that did not happen. The day-job slows the project down. My target completion date is sometime this winter. We will see :-| -Robert

I have been here a while without an intro. As a nerdy teenager I ground and autocollimation-figured my first optics, a 15 cm Cassegrain f/4 - f/12. The first views through those optics gave me a rush that I never recovered from. However, what I never could manage was to build a good mount. I have built many mounts that had two things in common, - they looked nice and they were unusable. My plan in the late 1970s and early 80s was to finish my degree, get a job, and in the far future buy a high-end mount to carry my big optics. That's why I ended up with the DDM 160 and a custom-built ASA truss tube with correctors for both prime focus (f/3.4) and Cass focus (f/10.4) designed for my 62 cm optics. This video sums up three years of construction work in two minutes. The video was fun to make, but as my optics are not yet finished, I had to borrow an HST/ESA-astrophoto from the public domain ;-) Regrettably, this object is far south of the Norwegian southern horizon, ...oh well https://vimeo.com/136882740 Cheers, Robert

Hi Michael, Thank you very much. The ASA software is like the ASA hardware: Spitzenklasse :-D Regards, Robert

Hi George, Many thanks. I see the point in allowing only beta testers to access the beta board. When I registered the version 5.1.1.6, I received a link to what I assumed was the lastest version. Unbeknownst to me, it was the lastest beta! Robert

Ooops, I see now that I am using the beta version without even knowing it! It has performed very well. I was just concerned about the altitude limit. I understand that I should have posted my question on the beta board, - but I can't find the beta board.

When I slew the mount with a Logitech gamepad, Autoslew ignores the limits settings (minimum altitude above horizon). However, when slewing using the slew buttons on the user interface, Autoslew consistently stops the slew at the altitude limit. Shouldn't Autoslew obey the altitude limit regardless of the input device? Autoslew version 5.2.1.0 Logitech Wireless Gamepad F710

Ooops, no problem. The pivot adjusted itself into position. The pressure from the pier simply pushed it into place. The day after I discovered the problem, it corrected itself! Regards, Robert

The large ball pivot in the center of the base plate of the DDM160 pier is difficult to align when mating the pier to the base plate. The female part of the pivot tends to lock in place at an angle. This prevents the pier from resting on the two cylindrical side supports which are welded to the base of the pier. Any tips on how to prevent this? Thanks, Robert W. Williams

Agreed. To put it back on topic, my first impression of the DDM160 is that it is 220 kg of solid, well thought-out engineering. Instrument to Declination axis distance The distance from the mounting plate to the declination axis is extremely short, keeping the counterweight mass to a minimum. This short distance is possible because of the absence of a polar axis drive gear, which on an "old-fashioned" gear-driven mount would have a diameter of at least 60 cm in a drive with the capacity of the DDM160. Mounting plate and pier The mounting plate for the ASA truss tube is massive, as is the pier. The latter was custom-made for a lattitude of 59 degrees. The base plate of the pier is also massive, with ten holes for anchoring bolts. Considering that the center of mass of the entire mount + instrument load + counterweights + pier is almost exactly over the center of the base plate of the pier, there is practically zero torque on the base plate. To be more precise, the intersection of the declination and polar axis is positioned only 9 cm north of the center of the pier's base plate. This is a very stable configuration. Packaging and crating Very well done. Can tolerate harsh shipping conditions without damage.

I would very much appreciate any tips you can give me. Many thanks! I haven't yet started installing it, but weather providing, I may start during the weekend.

Thanks. I will keep you posted. I update my website with the construction progress once a week or so: http://www.dinium.net/english/ I am usually behind schedule because of the day job and the weather. If I am extremely lucky with both, I may have the dome and mount in place by the end of November, in time for the arrival of comet ISON to the northern hemisphere.

I'm putting this on it (attached image). 62 cm f/3.4 - f/10.4. ASA made the tube and prime focus corrector for my optics.

I am a soon-to-be DDM160 user. It is still in its crate. By the end of November it should be on the pier.