With the mount’s base and RA assembled I was finally able to start working on the declination axis!
I started by finishing all of the cabling. There was still a bit of work left there. I managed to keep everything clean and arranged. As you can see on the picture, the worm and drive system are not installed yet, so that area needs to be accessible for the install, adjustments and maintenance.
Next I ran all three cables (12V DC, USB 3.0 and DEC motor/encoder) through the RA shaft. The DEC cable then goes toward the top bearing while the other two go to the bottom bearing. I made grooves in the back plate to guide them out of the bearing block.
I then installed the DEC gear housing, which I had already pre-assembled. It’s made of aluminum plates and a rolled aluminum bar. The assembly of this housing was pretty difficult. Tolerances on rolled aluminum of that thickness were a little big to my taste. I had to strap the cover to bring it to the right shape while I was drilling the holes for the bottom and top plates. That worked. But if I was to do it again I would just machine the cover out of raw aluminum.
At the bottom, well I was missing M8x70 socket cap screws. huh. So I couldn’t install the counterweight base/shaft. Not a big deal because I was also missing the M4x25 screws for the rear cap cover and encoder read head bracket. So… I cannot pull and straighten the three cables. In case you were wondering what was that red part hanging off the wires, well now you know.
Then with the help of my wife I installed the DEC shaft from the top bearing, followed by the bottom bearing. A little of temporary preloading on the bearings allowed me to naturally adjust coaxiality of the two bearing blocks. I installed the front plate of the housing and tightened all the screws for the bearing blocks.
To make it look half decent I installed the left and right plates. These will need to be removed when I take care of straightening the cables and running them through the DEC shaft.
And that’s pretty much all I did this week-end…