Hello fellow Instruct-ables... What better way to celebrate space than to look at it through a really big telescope? I have been an ATM for quite a while and this is my latest project, a big refracting telescope on a big mount.
Step 1: Gathering Parts
The mount is made from mostly easy to find scrap parts I found on line. I spent a lot of time looking for scrap pieces that were close to sizes I needed until I found that the metal merchants would cut pieces to size for pretty cheap. I used common power tools such as a small drill press, router, circular saw and chop saw. Working with aluminum is a lot like working with very hard woods, the cutting feels the same but slower.
The chassis is made of 1/2" sheet aluminum. The bearings are pillow block bearings. The Main(RA) shaft is 2-5/8" diameter aluminum and the smaller(dec) shaft is 1-1/6" steel. The large worm gear was purchased cheaply from an astronomy website.
Step 2: Routing aluminum
This is a step that I thought about for a good long while. An equatorial mount has to have some adjustment for the angle of altitude in order to track properly. The angle for your location is your latitude, Where I am the mount needs to be set at 42deg. I decided to make the angle adjustable about 5 deg either way. To make these small arcs I used a circle-cutter attachment on my router and made quick 1/8" passes until I cut through each side of the chassis.
Step 3: Basic chassis assembly
I trimmed the mounting tabs from the large pillow block bearings and ground down the sides with an angle grinder. After some drilling and some tapping, I bolted the base chassis up...
I added a brace and tapped a hole for an adjustment bolt. Turning this bolt allows the angle to be adjusted then clamped down when it's right.