After months of waiting the iStar 140mm APO finally arrived! And with it came the Apex ED flattener/reducer. While I was waiting I took my old Moonlite CSL focuser apart, replaced the 1 inch travel drawtube with a 3 inch travel version, added a 1.25 inch extension and a new base flange. Plus, I picked up the necessary adapters to hook everything together.
So in order from left to right we have: the SBIG SFT8300M camera, a ZWO EFW filter wheel, a Stellarvue adjustable T2 adapter, a Starizona adapter for the Apex ED and my rebuilt Moonlite focuser.
Putting it all together looks like this:
Neat and sweet. And adding in the other end…
Something seems to be missing… Oh, yeah. It needs a tube. As tempted as I am just to duct tape everything together (I do wear suspenders and I did once live in Red Green country) and get out imaging, I am planning a proper Optical Tube Assembly (OTA). It is going to be fully baffled with a retractable dew shield. I considered carbon fibre but couldn’t find an economical tube. So it’s to be aluminum. That’s fine with me as I am well setup for working with the stuff. The only downside to it is thermal expansion and contraction. But there are good work-arounds to compensate.
Here is the aluminum stock on the bench. There are a 6 and 7 inch OD tubes from Hastings Irrigation and 0.25, 0.5 and 0.75 inch thick chunks of of 6061-T6 aluminum from my local goto shop Metal Supermarkets.
The purpose of the tubes should be obvious. The plate will be used to make mounting rings, baffles and other necessary bits. Fortunately, I own a CNC machine, a Haas TM-3P, affectionately known as “Big Bertha” as she takes up a third of my workshop. Given what she can do, I don’t begrudge her the space. And she’s hungry to get her cutters in that stock!