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Observation by Eric Walker: 3D-Printed C11 Collimating Bolts

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Eric Walker


Eric Walker


2020 Nov 01 - 18:00


2020 Nov 01 - 22:37


The Bubble Nebula (NGC7635)

  • Celestron C11 (“Nexstar”) OTA
  • Ender3 3D-Printer
  • ABS and PLA filaments

Beinn View Observatory, Conon Bridge, Scottish Highlands


3D-Printed C11 Collimating Bolts

About this image

This weekend’s telescope improvement project: design & 3D-print collimating bolts for my C11 SCT.

Collimating (alignment of all the optical elements) is important for normal viewing through the eyepiece and absolutely critical for astrophotography & webcasting when using hi-spec astro-cameras.

The collimation bolts in this older C11 (Nexstar) SCT had a cross-head which required adjustment using a Philips screwdriver - not very practical and also a considerable risk of damaging the telescope specific, & expensive, corrector plate on the front of the scope.

So ..... after several design iterations using Fusion 360 I succeeded in printing the threaded bolt using tough ABS (“Lego brick”) filament inserted into a wide cap (PLA filament) - which makes adjustment in the cold & dark a doddle.

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