Even during the busiest times of my life I have endeavored to maintain some
form of model building activity. This site has been created to help me chronicle
my journey through a lifelong involvement in model aviation, which
all began in Mayo, MD
All trademarks, copyrights, patents, and other rights of ownership to images
and text used on the Airplanes and Rockets website are hereby acknowledged.
Installing the Feathertouch SCT MicroFocuser
on the Celestron CPC 800 Deluxe HD Telescope
After reading as many reviews on dual stage focusers, I finally decided on the Feathertouch SCT MicroFocuser for my newly acquired Celestron
CPC 800 Deluxe HD telescope. I wanted a dual stage focuser with a light touch instead of an electric focuser. The instructions were available
online and it looked like a cinch to install. In fact, it looked so easy that I decided to make a video in front of a live audience (the camera)
without a dry run. Being fairly adept at such things, I figured that any departure from simplicity would be immediately obvious. Without rushing,
it took 6 minutes and 15 seconds from beginning to end. The video is a little longer since I couldn't help editorializing for a couple minutes
at the end.
Oddly, no printed
instructions came with my focuser; I found them on the
Telescopes.com website as a downloadable PDF file. For that matter, the link on the
website of the manufacturer, Starlight Instruments, returns a 404 error (as of this writing*). It is obvious that the instructions were written by an
American in English and not translated. The photos in the instructions are excellent, as is the simple text. It was clear enough first to convince
me to buy the unit and second to allow me to confidently tackle the process without practice in front of a video camera. The only thing that
surprised me during the installation was that after unscrewing the factory ball bearing and brass cylinder, it would not be used anymore. I
stowed it in the little plastic bag that the screws for the Feathertouch SCT MicroFocuser came in.
The Feathertouch SCT MicroFocuser has "Made in USA" stamped on it - a rare sight these days (the CPC 800 Deluxe HD
telescope has "Made in China" marked on it, BTW).
* The link has been fixed since then.
If a picture is worth a thousand words, then this video is worth about 11 million words:
(30 frames/second) x (6.25 minutes) x (60 seconds/minute) x (1000 words/picture) = 11,250,000 words
Video: Installing the Feathertouch SCT MicroFocuser on the Celestron CPC 800 Deluxe HD
You can download the excellent PFD installation instructions
for the Feathertouch SCT MicroFocuser here, but I will go ahead and list the steps here, along with my observations.
1. Pull the rubber focuser knob off the brass cylinder. Rock it a bit as you go since the grip on the tube is pretty tight. It will
seem like the thing must be glued on until it breaks loose.
2. Remove the three flat head screws that hold the orange retainer plate in place. A #3 Phillips head screwdriver will do the job.
The plate and screws will not be reinstalled The screws on my CPC 800 Deluxe HD were surprisingly loose. The ones on my NexStar 8SE
telescope were much tighter when I removed them during installation of a JMI electric focuser.
3. Remove the screw and washer from the end of the central threaded rod (they will be reinstalled later).
4. Remove the ball bearing and brass cylinder assembly from the back of the telescope by rotating it counterclockwise. It will take
a lot of turns to remove it from the long threaded rod. My wrist was really tired by the time it was finally off. This assembly will not
be reinstalled, so I stowed it in the little plastic bag that the new screws came in.
5. Unscrew the brass cap from the Feathertouch SCT MicroFocuser and screw it onto the threaded rod of the telescope so that the end
of the threaded rod is past the open end of the brass cap.. Be sure the open end faces out since it will screw back on to the focuser.
6. Use a rag or Kleenex to wipe any grease from the end of the threaded rod and the screw hole. The screw appears to have a small amount
of light duty thread lock compound on it from the factory, so any grease will render it useless. The compound is no longer effective after being
removed, but its presence on the screw threads will help make the fit and grip tighter than without it. Reinstall the screw and washer onto
the end of the threaded rod and torque it
7. While supporting the threaded rod and brass cap, screw the microfocuser main body into the cap. Use a 1/2" open end wrench to torque
the cap to the microfocuser. Be very careful not to transfer the torque or bending moments to the threaded rod.
8. Carefully push the microfocuser assembly back into the rear plate of the telescope (called the visual back). I pushed mine up to
within about 1/2" of the back, then rotated the the assembly clockwise to snug it against the visual back. Use the three Allen head machine
screws to attach the Feathertouch SCT MicroFocuser to the visual back. To make installation of the screws easier, I chose to use a long Allen
wrench that clears the microfocuser rather than the short one that is supplied.
9. Give the coarse focus knob (1:1) and the fine focus knob (10:1) a few turns to make sure the telescope is functioning properly.
That's all there is to it.
As a side note, I want to mention a rather strange phenomenon that seems to be occurring now with the prices of telescopes and accessories.
If you are shopping for a new telescope or even a focuser, you will find at this point in time (see "posted" date at
bottom) that all the distributors are selling at the same price as the manufacturer. They advertise their "sale" price and compare it
to the list retail price, but if you go to the manufacturer, its listed price is what the distributors are charging. This is highly unusual
since typically manufacturers' prices are higher than distributors' prices. It is done that way to encourage customers to buy from distributors,
who traditionally move the most product Volume. It really makes the distributors' claims of price reductions a case of false advertising.
My advice is to call a few distributors and ask for a discount based on the fact that you can buy it from anyone for the same advertised
price. I got my Celestron CPC 800 Deluxe HD for $2,275 (w/free shipping) when everyone was advertising $2,399. The first place I called offered
no price reduction. I even got my Feathertouch SCT MicroFocuser for $230 (w/free shipping) when everyone else was demanding the full $239 manufacturer's
price. That's a $133 total savings - not a lot, but it'll buy me a couple tanks full of gas.