I purchase my Celestron HD PRO wedge around the end of September 2017 after my experiments with the wooden wedge. It hasn’t seen too much use through the winter, but I’m expecting big things of it. The wedge is rock-solid but I do have a couple of pet peeves, and recently ran into a minor but annoying problem.
I noticed that the azimuth adjustment “tongue” as I call it – the piece of metal that the two azimuth adjustment knobs work against, had developed a rather ugly wear mark caused by metal-on-metal contact.
The wedge is under a year old, so I could ask Celestron to fix it or send me a new adjustment rod. Yet, it should be a simple matter to fix so I thought I’d give it a try.
The azimuth adjustments are nothing more than heavy threaded rods, but each has a plastic insert embedded in the end where the rod pushes against the tongue. In one of the rods the insert was too short (or the end of the rod drilled too deep), so that the bushing pushed into the rod completely. Hence, the metal-on-metal contact.
I drilled a hole in the insert and used a sheet-metal screw to extract it. Then, I took the a 5/16″ nylon cap screw and cut it off to about 1.3 cm leaving only the smooth shank (a nylon rod). I inserted it in the shaft as a replacement for the Celestron part. The original part and hole are bullet shaped. My replacement is cutoff square and didn’t quite bottom out, but that’s OK. The 1.3 cm length had the new insert protruding about 2 or 3 mm beyond the end of the shaft, which is just about right. The 5/16 shank fit somewhat loosely in the hole. I wrapped one layer of tape around it for a snug fit. The original insert feels like it may be polyethylene, but I think nylon will do nicely in its place. If not, I’ll be sure to relate my annoyance to Celestron and ask for a replacement part.
The Neophyte Astronomer 