Improving the Celestron Astromaster 70AZ

[Rocket_the_Raccoon]

          

A little more than a year ago, I acquired this 70mm f/13 long refractor for merely $40CAD and wrote a quick review on it : 
https://stargazerslounge.com/topic/295880-celestron-astromaster-70az-review-and-improvements/?tab=comments#comment-3239177

Recently I have made some further improvements on the scope to create a quick and lazy observing setup for me :
- dovetails and tube rings for balancing the OTA, note that the tube is smaller than the standard 76mm ID tube rings and thus requires ~2 layers of felt pads for a tight fit.
- Celestron prism star diagonal replacing the low-quality and stopped down Amici prism
- 6x30 finderscope replacing the hard-to-use star-pointer, also better suited for a light-polluted sky, finderscope base was super-glued to the OTA instead of drilling holes.
- because of the f/13 ratio, the stock 20mm and 10mm both perform very well
- added a Meade 12.4mm Plossl for nights with only fair seeing
- added a 1st generation 8mm Brandon for nights with good seeing
- added a homemade 33mm for DSO's, TFOV 1.6 degrees (stock 20mm gives 1.27 degrees), please see https://stargazerslounge.com/topic/314649-diy-6-element-33mm-eyepiece/?tab=comments#comment-3441384
- added a Skywatcher Crystalview Moon filter for obersving the full moon with the stock 20mm, also for slightly enhanced views of bright nebulas.

 

 

 

[Demonperformer]

Great improvements.

How do you find the tripod? From the pics it looks very similar to the one that comes with the 102, which I always found to be a very weak point of the system. I found it was improved greatly by rigging a means of hanging a weight from the centre of the tray, lowering the centre of gravity.

[SIDO]

Those are some nice upgrades, I have made a ton of mods to my favorite achromatic refractor and its still ongoing, like the new rings and dovetail...now your ready for most any mount you come across.

[Rocket_the_Raccoon]

14 hours ago, Demonperformer said:

Great improvements.

How do you find the tripod? From the pics it looks very similar to the one that comes with the 102, which I always found to be a very weak point of the system. I found it was improved greatly by rigging a means of hanging a weight from the centre of the tray, lowering the centre of gravity.

Thanks. As for the tripod, which 102 are you referring to? This particular one comes with the scope and has a design flaw that the metal rod/handle sits above the altitude axis, making the setup almost always back-heavy. This was mentioned in my review of the scope in an earlier post. For this reason, the dovetail and tube rings were used so that I can balance the OTA. Lastly, hanging a weight from the tray centre is indeed a good way to stabilize the whole setup but as currently, vibrations pretty much die down within 2 seconds even at 112x, I had simply skipped this step. 

[Rocket_the_Raccoon]

13 hours ago, SIDO said:

Those are some nice upgrades, I have made a ton of mods to my favorite achromatic refractor and its still ongoing, like the new rings and dovetail...now your ready for most any mount you come across.

Thanks, I personally is a fan of refractors, especially for slow ones like this. It is unfortunate that they are not made any more (at least not in large enough volumes to be affordable). And yes, the new rings and dovetails made balancing possible on any mount. The original fixed dovetail is so limited but it does act effectively as a balance weight in this particular setup.