Showing posts with label counterweight. Show all posts
Showing posts with label counterweight. Show all posts

Monday, July 18, 2011

Counterweight

With the vast variety of accessories, starting from a different weight eyepieces, the OTA center of gravity might shift considerably towards the open end. Which is often perceived as the altitude bearing failure and usually addressed by a sort of adjustable braking system over the altitude semi-axes hubs, plus a habit of applying and undoing it. In my opinion  that just consumes observing time and neglects the dobsonian construction principle: "simplicity - first".

Luckily enough the Zhumell Dob OTA material is a plain steel which is naturally ferrous. The solution came in a snap. An old steel (also ferrous) counterweight scavenged from my old cheap refractor mount (4.2 lbs), a couple of strong neodymium magnets harvested from a broken hard drive, and a stripe of blue masking tape for scratches prevention - all were sticking to each other almost by themselves.