Making some progress with the Edmund 8" No. 4005 (a.k.a. as monster focuser bearer).
I am working on the issue of the OTA hole for the focuser, which the previous owner enlarged to install an aftermarket Crayford focuser (Pic 1).
First I made a cardboard template with a smaller hole (2.6"), which I guess is more proportionate to the 2" focuser tube (Pic 2). I positioned it using the original guiding focuser holes as reference. Then I installed the guiding focuser and verified that the hole is centered. It is (Pic 3-4). Note in pic 4 the prism that gathers the image for the 1.25" guiding focuser.
Next I traced the template onto a piece of black neoprene sheet from an art supply store, and glued over it a black fabric sheet also from the same source (pic 5). I re-cut the hole for the 2" main focuser tube. This flocked neoprene sheet was installed over the enlarged focuser hole, flocked side towards the inside, and will be retained by the focuser base itself, and probably a dab of contact cement.
I ran however into a problem at that point. I realized that the retaining screws of the focuser base plate where pulling in and deforming the OTA (pic 6).
The solution that I came up with is to use a 10-32 nut and a washer as spacers between the OTA and the focuser, to support the former (pic 7).
Next I will have to clean the mirrors that, from what I can see so far, seem still in very decent condition. I thought at the possibility to have them recoated since I have Majestic only 20 min away, but to be honest I do not feel like dealing with the complication of re-assembly and collimating the secondary, which has a rather complex system of adjusting bolts and screws.
Edited by DMala, 04 January 2019 - 09:46 PM.