Alt / Az mounting my OMC140
Posted: Sat Dec 24, 2022 2:40 pm
My OMC140 ( 140mm Maksutov) was actually always a tad heavy for the Alt/Az mount my GrabnGo 102mm Maksutov normally sits on.
The little 102mm Mak has an quiver time of less than half a second when focusing. Moving into Alt or Az is very smooth, with no noticeable vibrations.
The little Mak on Alt/Az
The almost double-weighted OMC140 makes that just two seconds. The Alt/Az movements are still smooth. But that depletion time is crippling for fun focusing on planets, for example. Too bad.
Until I started thinking logically and mounted the arm from which the telescope hangs upright on the tripod. This way the telescope does not "hang" behind the vertically running Azimuth axis (see above), but is balanced exactly above it.
OMC140 is balanced here, all brakes released.
The extinction time decreased by more than 1 second and sits just above half a second. Logical actually. Planet-worthy, even on Jupiter. At least now I can see that during focusing, the planet "clicks" into focus. Alt/ Az movements are still smooth. Really GrabnGo it's all not, of course, but I still catch a suddenly appearing Orion Nebula among the clouds. One drawback is that for zenith observing there is not enough space between zenith mirror and mount. In that case, a shorter zenith mirror mount and prism must be fitted.
Next to it hangs a clever 50mm viewfinder with Amici prism that can be transformed by changing eyepieces from 8X50, via 14X50 to 18X50. The latter is no superfluous luxury in my location.
Edit: With the 102mm Mak mounted this way, I hardly notice any vibration during focusing.
The little 102mm Mak has an quiver time of less than half a second when focusing. Moving into Alt or Az is very smooth, with no noticeable vibrations.
The little Mak on Alt/Az
The almost double-weighted OMC140 makes that just two seconds. The Alt/Az movements are still smooth. But that depletion time is crippling for fun focusing on planets, for example. Too bad.
Until I started thinking logically and mounted the arm from which the telescope hangs upright on the tripod. This way the telescope does not "hang" behind the vertically running Azimuth axis (see above), but is balanced exactly above it.
OMC140 is balanced here, all brakes released.
The extinction time decreased by more than 1 second and sits just above half a second. Logical actually. Planet-worthy, even on Jupiter. At least now I can see that during focusing, the planet "clicks" into focus. Alt/ Az movements are still smooth. Really GrabnGo it's all not, of course, but I still catch a suddenly appearing Orion Nebula among the clouds. One drawback is that for zenith observing there is not enough space between zenith mirror and mount. In that case, a shorter zenith mirror mount and prism must be fitted.
Next to it hangs a clever 50mm viewfinder with Amici prism that can be transformed by changing eyepieces from 8X50, via 14X50 to 18X50. The latter is no superfluous luxury in my location.
Edit: With the 102mm Mak mounted this way, I hardly notice any vibration during focusing.
