East Dome Committee Meeting Minutes
October 11, 2007
A meeting of the FBAC East Dome Committee was held October 11, 2007 at America Buffet in southwest Houston. Attending EDC members were Bill Dillon, Joe Dellinger and Dennis Borgman. An invitation was extended to all interested FBAC members on October 10, 2007 via netslyder. There were no other attendees at the meeting.
This meeting's focus was on selection of a replacement drive system on the club's 18" telescope located in the East Dome at the George Observatory. The strong and weak points of each of the three prospective drive system vendors were reviewed. The drive vendors were Gemini, used on Losmandy german equatorial mounts; ServoCAT from StellarCAT; and SiTech from Sidereal Technology.
The Gemini system, is used by a very prominent mount vendor, Losmandy, but seems to be intended mostly for German Equatorial mounts. When asked about it's support of Equatorial Fork mounts, the engineer replied with comments that it would be treated like a GEM doing a meridian flip. It seemed apparent that they weren't very familiar with fork mounts. This put doubts in all of our minds about getting a product ready to run without significant efforts troubleshooting new software. A second concern with Gemini, was the small motor available with the system and possible problems with sufficient torque to drive our heavy fork mount. A third concern was that in choosing Gemini, we might be going right down the same path we did with AIM Controls, ie. a single vendor solution with debugging software and hardware problems forever and never quite getting what we wanted. The engineer that would fix problems with the system was in Sweden, very remote.
The ServoCAT system by StellarCAT is extremely popular with DOB telescope owners and manufacturers. They have designed a very reliable and successful product aimed at the Alt/Az drive market. Although StellarCAT claims the ServoCAT will work with no problems on a fork mount, we couldn't find any current installations. We don't want to be the testor for this drive on fork mounts any more than for Gemini. Our goal is to find a proven drive ready to go for Equatorial Fork mounts. Some other issues with the ServoCAT were no ASCOM interface and no current support for Periodic Error Correction or plans for it.
The SiTech system from Sidereal Technology is relatively new with a little over 100 installations as of this report. Again, like ServoCAT, SiTech is primarily aimed at the Alt/Az drive market. However, Sidereal Technology does have installations on Equatorial Fork mounts, including one on the designer's own 14" fork mount. The SiTech system includes ASCOM drivers and PEC. The only negative that we could see at this time was that MegaStar may not work with it, as MegaStar currently does not support ASCOM.
The Sitech system clearly offered more in a proven package than the other two vendors and was the unanimous choice for the FBAC 18. It was also decided that we buy the complete package that includes the basic servo drive box, 2 geared servo motors, wireless hand paddle and guider interface, and the Argo Navis control computer. Should any part besides the basic servo drive and motors fail, the telescope is still fully operational. A personal computer may also be interfaced to the SiTech for even more backup flexibility.
Status of go do's and commitments from previous meetings:
- Joe Dellinger - Investigate paneling for the ED and cost. Incomplete.
- Dennis Borgman - Contact Robo-Focus about repair. Incomplete, not sure if RoboFocus is still wanted.
- Dennis Borgman - Investigate guide scope focuser problem. Holdover from last time. Incomplete.
- Bill Dillon - Schedule training day for July. Complete 8/5/2007. Carl Sexton and Jeffery Amos received training.
New go do's and commitments from October 11 meeting:
- Place order for new drive system.
Items completed or removed from the ED open task list
Progress on open items from the ED task list
- There are 14 open items on the ED task list.
- No update on progress.
New items added to the ED task list