telescope filter adpater

This is my first attempt to do a file in openscad. I have a telescope and I got a top class solar filter solar very cheap that is too small for my telescope. So, I decided to give it a try and make an adapter to fit the filter.

Basically is a reducer. Need to fit in the outside of the telescope aperture and fit inside the filter rim.

Initial files had a problem. Openscad does not have measure units. When I imported in Cura to produce gcode I found out that the object was too big. I was able to scale down the object to the size needed, but in the process I also scaled down the thickness of the object. So I made a design that has double of the thickness, so when is scaled down the thickness is still wide enough. This is to block sunlight, does not need to be waterproof, but it needs to be opaque.