Quote:
Originally Posted by erick
Yes, apart from a few things that are not too hard to fix (springs, straylight shield, fix the staples in the teflon etc), he is giving it a good review.
One thing I didn't understand. The centre of gravity can be altered at the altitude bearings. It looks like it needs a screwdriver to loosen two screws then slide the OTA forward or back, then tighten. I wouldn't have thought that was a job one would do between eyepiece changes, but he seemed to be suggesting that he was doing this?? He says "all I had to do was crank down the ALT bearings". Or perhaps he meant - tighten the bearings?? What do you understand by this?
|
Hi Erick,
The trunnions on either side of the lower part of the OTA (i.e. the mirror 'box')
can be adjusted in two ways.
Firstly, there are two screws on each trunnion that, when loosened with a Philips
head screw driver, allow the trunnions to slide up and down slots on the side of the
OTA. This then changes the center of gravity of the OTA. Since both trunnions
are identical, one needs to adjust both to prevent the OTA being skew and a
graduated scale helps the operator determine they will be at the same height.
This is certainly not an operation you are likely to perform each time one
changes to a different weight eyepiece.
The second level of control is provided by the large aluminium knobs. Tightening
or loosening them controls the function of the needle thrust bearings and one
can therefore control the amount of stiction the OTA has in altitude. Tighten
then way up and the OTA will not shift under gravity.
Best Regards
Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place, Mount Kuring-Gai
NSW. 2080. Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
sales@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au