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Disclaimer: All the how-to directions below are for information only. They are not intended to be sold or used for unlawful purposes. The author takes no responsibility if they cause the reader bodily harm, loss of life, or cause the damage of any property, person, dog, cat, or any other animal. They are presented for information only and all liability is on the part of the reader.
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Creating a simple adapter for a Coronado 60mm, 70mm or 90mm MaxScope to a JMI NGF-C focuser
Preface: I love my 90mm MaxScope and my 70mm Cak Scope. Both are well engineered and built to last. The solid aluminum bodies and anodized gold tubes make the scopes that much more beautiful. The only fly in the soup is the focuser. Its ok for visual use but for imaging is really hard to get used to. When turning it the whole scope moves and it binds pretty often. To remedy this I started looking for a way to attached an after market Crayford to the scope. I had seen where other attached a JMI NGF-CM focuser to their scopes so I decided to look into it. The manual version of the focuser was around 165$ brand new. If purchased from JMI you could also get different colors at the time. Recently I just learned that they discontinued the NGF-C focusers in favor of the new Event Horizon line. You can still find one on www.astromart.com as they were pretty popular focusers. The Crayford action beats the helical focuser that came with the MaxScope hands down. It is simply the best upgrade you can make to your scope. Getting the focuser was easy adapting it to the scope was a little tricker. The official adapter is made by Coronado and carries a Coronado price tag too. At $200.00 the adapter was pretty costly. Even more so than the focuser! For my Calcium scope I decided to try building one. Below are the results.
Step 1: Get a used focuser first
The first step will be to obtain a used "Synta" or "Orion" refractor focuser. The condition does not matter so long as the drawtube is in good shape. I got two from www.astromart.com for around 20$. Below is what one looks like. Most folks replace these when they wear out. If your desperate you can call Orion telescopes and order a new one for 25$~30$.
Step 2: Cut the focuser
First remove the visual back and spacer ring from the Synta/Orion focuser. Next take the focuser apart and cut the tube 1 inch from where the threads start as seen below. Put the spacer ring back on the cut piece.
Step 3: Put it together
Screw the adapter onto the Coronado scope back and once its tight put the JMI NGF-C focuser on to the 2" side of the adapter and tighten the set screws. That's all there is to it.
