Tasco Vixen 8v
Posted 02 May 2009 - 05:31 PM
The package arrived yesterday...OMG. It was new and unused. I was pretty excited. Everything from the scope, to the mount, to the tripod was all in mint condition with no signs of even being used or even exposed to the elements-even inside
The package came with 125mm Vixen Cat Newt (not really) FL1000m (really 500mm with a 2x barlow in front of the secondary), Vixen Polaris mount with polar axis finder, Vixen 6x30mm finder, a very nice Vixen 18mm .965" Ortho ep, and the not so nice Vixen 5mm Ortho eyepiece.
But, the real point of this post is to provide information on collimation. I found the collimation set up to be intricate, but accurate, and the machining tolerances to be Takahashi Like.
So, here is a picture of the telescope...
Posted 02 May 2009 - 05:33 PM
Posted 02 May 2009 - 05:35 PM
Posted 02 May 2009 - 05:38 PM
1) Aligning the secondary under the focuser-you can see the secondary stalk has a large collar at the front with a lock nut around that collar. The corrector plate has a corresponding lock nut on the other side of the glass. You adjust the position of the secondary mirror by threading or unthreading the lock nut and then locking it down with the one on the other side of the glass. This is easy to accomplish with everything on the scope set up properly.
2) Primary Mirror-Fixed in what appears to be a very nice, unadjustable cell.
3) Secondary adjustment-You can see the 3 set screws. These press on the stalk holding the secondary and adjust the secondary just like any other secondary. Seemed easy to use.
I hope at least pictures may help future buyers of this very nice telescope.
Posted 02 May 2009 - 06:12 PM
Posted 02 May 2009 - 08:04 PM
Collimation is important in these 'scope so you want to use laser collimator to get things dead on the money.
In small apertures this design works well.
Posted 02 May 2009 - 10:15 PM
I do have a laser collimator and hope to get it out under the stars tonight.
Posted 03 May 2009 - 11:00 PM
Posted 03 May 2009 - 11:30 PM
outside lock ring to allow positioning under the focuser and rotational alignment. Then, make sure this lock ring is very tight. I failed to do this when I went outside last night for a star test. When I was adjusting the lateral set screws (hard to get at) to adjust the secondary, I ended up rotating the entire assembly.
It is really easy to pull off the front glass and remove the secondary. So, if you can confirm the one on Astromart has the barlow/corrector in front of the secondary, it will also be easy to repair the dents. A nice 5" Vixen, rings, with the very nice 18mm ortho and 6x30 finder seems like a decent deal for $75 or less.
I am not gong to fuss with collimation anymore until I see the master (Clint) later this month
Posted 04 May 2009 - 09:30 AM
What is critical is that the optical axis of the barlow/corrector is the same as the primary. If the lens is tilted or has the it optical axis offset from the primary, the image will suffer greatly.
One other thing to check, be sure that the diagonal mounting assembly is mounted so it is centered in the optical window and the window is centered in the cell.
Posted 04 May 2009 - 08:10 PM
I really love these Polaris mounts...
How much lighter are these compared to the SP/GP mounts ?
I always liked the 8v, just out of curiosity......glad it has good optics. 150x is what my Red Tasco 10VR can handle pretty easily.
Posted 05 May 2009 - 04:31 AM
I don't have a polar finder though... But looking at your picture: doesn't the polar finder need to be shoved more into the mount?
Otherwise when switching to AZ-mode (within a matter of second with this mount) the scope will hit the base plate.
Posted 06 May 2009 - 08:37 PM
Jae, you are right, the polar axis finder does go nicely up into the mount, basically hidden from view. As to size, I would say the polaris is about 60% of the SP. My CW shaft is threaded. Not sure I have seen a smooth one before.
Posted 10 May 2009 - 02:35 AM
My Polaris at present has a smooth counterweight bar which I swapped out of my CG-5. (Isn't it nice that all the polaris series mounts and their Celestron clones share the same threads on those bars) I am currently using two 7 lb. weights to balance my Brandon with all the heavy attachments hanging off it and that is probably as much weight as it will take gracefully. (My mount also came with a Tasco 8V so I am not totally off topic.)
Although Celestron never made a dec drive for this mount JMI did and I was fortunate enough to acquire one from a fellow CNer. The dec drive control attaches to the MD-6 hand paddle so everything is together.
Clear skies and strong backs to all
Posted 10 May 2009 - 05:22 PM
Posted 12 May 2009 - 02:48 PM
Optics look okay. Not in very good condition but I'll attempt to collimate it anyway. Looks a lot tougher to collimate than my C6/C8's and Newts.
Posted 11 July 2009 - 04:13 AM
Posted 13 July 2009 - 07:34 PM
Nice, an unused one. Congradulations.