Helical Crayford Focuser for Newtonian Telescope

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The Crayford design ensures precise focus adjustment without requiring a rack on the focuser tube, making it suitable for ATM usage. The helical Crayford's design was chosen first due to its ease of printing. By rotating the focuser tube, the eyepiece moves in and out like a telephoto camera lens. Recently, the design has undergone significant changes, with bearings attached to 'petals' similar to a camera iris that are held shut by a large hose clamp. A focus tube lock screw is still needed, but check out the new design! However, sourcing a 1-1/4" (31.75 mm) ID aluminum tube may be challenging. Stay tuned for solutions to keep the focuser tensioned on the tube. The mounting plate has extra holes for flexibility, allowing users to attach it to different focuser designs after gluing it to the optical tube. Remember to insert M4 nuts in each hole before gluing and ensure an eyepiece fits before gluing the eyepiece lock into the focuser tube. Lastly, consider adding a PTFE-made handle on the focus lock screw's other end to prevent damage and act as a clutch for friction during spinning.