Flocking the OTA

After reading about the improvements of the Meade OTA's contrast when adding flocking paper to the inside of the assembly I had considered doing it for many years.  I finally got up enough nerve to take the corrector and mirror out and do it!  I used the ProtoStar flocking Paper from Kendrick Astro Systems. The paper costs $.60 a linear foot, it is 30" wide. 48" is enough to do two 10" OTAs when cut lengthwise in half, with enough left over to flock the inside of your diagonal and other accessories.  I am going to try to do a side by side with a friend who has the same OTA, made at almost the same time.  Side by side comparisons showed my OTA was dramatically more contrast and virtually no off axis reflections!!

Step one is to remove the corrector plate.  The plate is quite thick at almost 1/4" so breaking it will really require dropping it or prying with a hard tool like a screwdriver.  Remove the button headed Allen machine screws and the plastic trim ring.  The corrector may or may not come out easily at this point.  In my case, it fell out as soon as the trim ring was removed.



Here is the corrector and secondary assembly after removal.  Note the index mark (whiteout and pen line) the red marker line is mine.  I plan to blacken the edge of the corrector plate after documenting the various inscriptions and markings. 



Here is the finished corrector, blackened edge, flat blacked secondary baffle and all.  Compare to the previous image.



The matching index mark on the OTA, same stuff (whiteout and pen line).  Note that I also flocked the area outside the corrector plate.  I even flocked the raised area just inside the corrector.



Here is the mirror and slider tube assembly.  The focuser rod is just hung on the pin, so once the mirror is removed it can fall off.  You have been warned!



Backside of the mirror showing the rear of the slider and the focuser bracket.  Note the date, 11/24/99.  The little green sticker on the outside of the OTA is marked 10799, I had originally thought that meant 1/07/99 but this is obviously not correct.  Anyone know the code on the sticker?

The piece of flocking paper needs to be 12 7/8" wide and roughly 39" long.  You can install the paper in several pieces if you want.  I got gutsy and did it all in once piece.  I also used to install those huge Pontiac Firebird decals on the hoods of cars for a local body shop too.....

Looking down the tube now without a bright light (like my SpeedLite on the camera) is like looking into a little cave!  Note the interior of the baffle tube after wafting and brushing Ultra Flat Black Krylon paint inside.  The two clearance slots are needed to get the mirror out of the tube.  The flocking paper is in place and appears seamless.  The trick is to overlap the pieces and trim with a knife. 

I sprayed the inside and outside of the secondary baffle with Krylon Ultra Flat Black.

A shot of the secondary mirror assembly showing the threads for the secondary baffle.  This joint is what keeps the secondary from turning.  Before taking the corrector out I marked its position.



The plastic trim & retainer ring, with the two paper shims.  If they come off of the tube be careful you don't lose or break them!  I glued mine back into place with some solvent free adhesive, just enough to keep them positioned while putting the corrector back in. 



Once the flocking paper is in place and just prior to closing up the tube by installing the corrector, use this guy to pick up extra fuzz from the flocking paper and any other deebers (debris) that made it into the OTA.


Don't forget to re grease the slider area of the baffle tube for the mirror to move smoothly.  I elected to use Finish Line Synthetic grease with Teflon


Another good grease which I use on telescope drives and other parts is the  Phil Wood waterproof grease.


Both of these products are available from REI and most high end bike shops, about $7 per tube.  Both of these have the same consistency at 0F, about like thin peanut butter.

I elected to replace those infuriating button head Allen screws with standard head Allen screws in black oxide.  The rest of my telescope has stainless Allen screws installed but here I wanted a mat finish.

Tube reassembly Aug 1st, 2006.  First light, who knows it's monsoon season.