DIY Two Position Filter Tray ( and no 3D printers in sight! )

[ArmyAirForce]

Never one to spend money if I can help it ( and reluctantly when I have it ), I've done some astro DIY over the last 24 hours. My manual filter wheel has moved to my recently purchased QHY163m deep sky camera, and now contains my Luminance, RGB and Hydrogen Alpha filters.

That left my ASI120MM-S camera with the 742nm Infra-Red Pass filter for lunar images. Now that I have the Calcium K filter for the Sun and clouds on Venus, I didn't want to have to keep swapping them over. Also, if I'm shooting Venus, I'll want to switch between the IR and CaK filter for a clean planet image and cloud detail.

So being too tight ( and broke ) to buy another filter wheel, I decided to make a two position tray for the IR and CaK filters. I had a spare camera nose piece and another camera adapter that I could use and the rest was made from acrylic sheet and styrene from the scrap box - by hand! The good old fashioned way.

A small hole in the side of the tray contains a ball bearing under a compression spring. The spring pushes the bearing towards the filter tray where it locates in a small hole, allowing the tray to click into position for each filter, ensuring they line up under the camera. A small cover plate holds the spring in place.

It was finished today, so now I just need some clear sky to test it. Looking at the forecast, that could be the longest part of the project!

[saac]

Neat design.

Jim 

[MarkAR]

Simple and well executed design, a bit like the old Victorian slide shows.