Anthony Horton

Given all the lights that shine onto my telescope when it's in my back yard I decided to make a lens hood for it to keep stray light out of the lens.

I'm considering this the Mark I prototype. It's a super simple conical design with a single baffle at the entrance aperture. I knocked the design up in FreeCAD, sliced in Prusa Slicer, and printed it on my very dusty Prusa Mini+. It's printed in shiny "Ocean Blue" PETG because I didn't have any black filament handy. The fit is OK, though it's just a little looser than I'd like.

If the weather cooperates I'll try this out tomorrow, and if it works well enough I may get myself some matt black filament and print a more refined version. Maybe add a few internal baffles.

#Seestar #SeestarS30Pro #Astrophotography #FreeCAD #FreeCADFriday #Prusa #3Dprinting

Jun 19 at 12:38pmWeb
Show threadWorkshopshed1d ago
@spacelizard why not spray with several coats of matt black paint to fix the fit and colour problem at the same time?
Show threadAnthony Horton1d ago
@Workshopshed When it comes to me and my 3D printer it's very a much a "if all you have is a hammer, everything looks like a nail" situation. I don't have many other tools or materials, nor suitable places to use them. My making space is just a desk in our 3rd bedroom/home office.
Show threadmjr1d ago

@spacelizard @Workshopshed I use a 3D printed aperture guard and I second matte paint. The go to recommendation is krylon ultra matte but any matte spray paint will perform better as a light baffle than plastic. What you want is the interior of the guard to have texture so don't over spray until the surface is wet looking.

You can also add a screw thread to the inside to make it harder for light to scatter into the lens. I think this would be necessary without paint

Show threadAnthony Horton1d ago

@madjohnroberts @Workshopshed Sure, a low reflectance matt surface is desirable, but there are other ways to prevent light scattering off the inside of the hood from entering the lens (that's what my comment about internal baffles was about), and I just don't want to mess around with paint.

I actually enjoy the challenge of coming up with designs that can work straight off the 3D printer with minimal or no post-processing. Usually, anyway. It's like the flying model rockets I did a few years back where I didn't use paint, glue or fasteners.

Show threadFreeCAD1d ago
@spacelizard Great stuff hope it blocks all the pesky light!