This was intitially posted on Cloudy Nights
Finally stopped raining long enough to put my WD 20 to the test with my AP152 mm F9 scope. Scope and mount are depicted below.
The mount was placed on my Losmandy HD tripod with a 12 inch extension and an AZ8 riser. The AP scope weighs ~35 lbs and is about 1.5 meters long as configured in the picture. The tripod was weighed down with 30 lbs of weight, which I believe was probably overkill, but better safe than sorry. The WD 20 was configured in Alt Az mode. Tripod and mount were leveled using a bubble level. Power was provided using a Jackery 500. I have not updated to the most recent firmware. AEB and EC HA were disabled. It is late so I will just give some bulleted observations.
-
I am a happy camper!:-). This mount swung the scope around like it was nothing. Goto’s were pretty good after first sync. I did not do any alignment.
-
I viewed Jupiter, Mars, M42 and M45. A key factor for which I had interest was the damping behavior during visual observation. The scope did pick up vibration. Below 150x, it was negligible, with tapping vibrations damping out in about a second. At ~200X, vibration during focusing became evident, and at 300x damping time extended to ~2 seconds, but still was mostly settled after 1 second. However, the image was steady during tracking at 300x and vibration due to centering the planet damped out in under 1 second. There is not a lot of play in that drive train:-). Frankly I was impressed with the performance and had a fun time viewing Europe’s transit at 300x.
-
As I said, i did not attempt to do any star alignment, but instead simply synced to a target. Using this approach, there was some minor drift as one might expect. At 193x with a 7 mm Nagler Mars drifted from the center to the edge of the AFOV in about 30+minutes. That is certainly sufficient for outreach events and I would expect even better performance with a 3 star alignment.
I am very happy with the mount’s performance. This large refractor is an extreme use case. The hand controller continues to grow on me. For such a light weight mount, I thought the damping times were pretty good. It is not my G11T on a pier good, but then the mount head does not weigh 60 lbs either:-). It certainly equals my 40 lbs Atlas for vibration and easily bests it for consistent goto’s. The Atlas was my travel mount for this size scope. Next steps will be to test the mount with EAA and then ultimately in GEM mode for guided imaging. The mount is very impressive once you get past the On Step learning curve.
Cheers!
JMD
