1) How to collimate an ASA Astrograph?
We recommend the Cats Eye collimation tools
http://www.catseyecollimation.com
ASA main mirrors are marked with the Cats Eye triangle. We recommend ordering the Telecat XL and the Autocollimator XL. With our Astrographs we supply a detailed instruction for collimation.
2) How difficult is it to collimate an ASA Astrograph?
If you keep the rules collimation is very easy. With a fast System the accuracy of collimation is critical for the imaging quality. Thus one should investigate the time to altercate with that issue to bring out the best of your Astrograph. The collimation is stable over a long time period. A very detailed instruction for collimation is supplied with our Astrographs.
3) I like to apply Focus Max and Maxim DL to control the ASA OK3 focuser?
You can. You will find the driver on our website:
Link
4) How can I remove the main mirror for cleaning?
Put the telescope with the main mirror up on the floor. Remove the back cover. We recommend marking the mirror cell and tube with a tape. Remove the three pull screws – those are the middle one of the three adjusting screws. Remove the mirror cell with the mirror carefully. After cleaning you can realign on the tape markers how to assemble the mirror. With that approach naturally only a slight decollimation has to be realigned.
5) What is the loading capacity of the ASA OK3 focuser?
Each focuser is tested under continuous operation at factory with 5kg loading. Thus the loading capacity is guaranteed up to 5kg.
6) What function have the three white plastic bolts which are positioned toward the main mirror?
The main mirrors of the 8” and the 10” serial are glued. The main mirrors of the 12” and 16” are mounted on a 9 point floating cell. In all cases the white plastic bolts have the function to secure the mirror against moving. We recommend a space between mirror and bolts which allows inserting a paper sheet between.
7) How can I protect the secondary against moisture?
We recommend preparing a short dew cap which together protect against stray light. Rough rule of thumb: Length should be no longer as the diameter of the main mirror measured from the end of the focusers plate.
8) What is the one step size with the ASA OK3 focuser?
Ten steps are 8,5 micrometer = 0,0085 mm
9) What is the reflectance of ASA mirrors at 1500 nm?
Reflectance of ASA-mirrors at 1500 nm is in the order of 86 - 88%. However, if one wishes, we can optimize for surcharge a special coating to perform up to 95% at 1500 nm.