I have made an adaptor for COKIN Z pro gradient ND filter for lens with 81 mm filter thread. You will also need some additional parts. An 81mm to 95mm Step Up Ring (1 Qty) Flocking Paper (1 qty) M2.5 heat set insert (7 qty) M2.5 X 17 mm Counter sunk bolt. (6 qty) M2.5 X 8 mm (1 qty) All the parts link can be found in the description of the video.

Magnetic Snap Fit Focus Mask design for GSO 8 inch Dobsonian Telescope. There are multiple designs. Bahtinov Tri Bahtinov Tri Bahtinov 2 Heartmaan HeartMaan Bahtinov Combo AstroIndi design Adaptor for GSO 8 inch Dob Colimation Mask adaptor.

DIY 3D Printed 2 inch Prism Diagonal for Telescope, using BK7 Optical Glass with More than 90% transmission across the visible and near-infrared spectrum. This build saves roughly 50 to 60 $

I design and 3D print a custom light shroud for my 8-inch telescope to improve contrast during visual observation.

Full Moon was too Bright so I made an aperture for my telescope instead of buying a filter. I designed and 3D printed a variable aperture iris mechanism that lets me precisely control how much light enters an 8-inch telescope — dimming bright objects like the Moon to a comfortable viewing level without degrading contrast unnecessarily. This is based on GSO 8 inch Dobsonian Newtonian 1200mm focal length f/6 Telescope for detailed Video refer link

Made a UV reactor for Aquarium.

Made a Light box or Ray Box for optical experiments. it can be used to form rainbow, or demonstrate how concave and convex lens work, how mirror reflect light, angle of incidence is equal to angle of reflection, formation of rainbow, total internal reflection, principle of refraction etc.