For a personal project I created a telescope with optical baffling along the inside of the tube. Its a project I have wanted to do for bit and to also take one to a real dark sky area.

- 4x Al Tubes on each corner

- 11x Common 3d printed cross sections

- 1x transport cover / cap

- 1x Primary mirror mount (120mm diameter)

- 1x Secondary mirror and eye piece section. 

- 1x Off the shelf trip pod

- 1x alt aiz mount

- 1x tripod to Al tube adapter block.

- common fastener and nut pair. (low tool count for assembly)

This was an objects for both testing / iteration, cleaning, and condensing down for travel either saving some space in a trunk or flying with the unit packed into a case. While the unit can be disassembled and reassembled, I found that over optimizing the filament use resulted in the walls being a bit too thin for this to be repeatedly done. Optimization was done to A) reduce filament cost and B) also to guarantee that a print would not require reset meaning that each spool would give n.2 for example whole sections with and "acceptably" small amount of spool left. Due to over optimization the nuts will eventually deform their pockets which retain them. This is something I will address on a follow up if another is made.

The Al tubes act in a few capacities A) To allow for stacking of the sections, B) To add some additional rigidity, and C) To act as attachment points for other accessories. Other accessories being the tripod to scope adapter, a finder scope, and possible a go to system at a future point.

Autodesk Fusion 360 and Prusa Slicer were used in the design. The slicer acted as a feedback mechanism allowing for the design to be adjusted for not only for use, and assembly, but also for ease of printing. For example shapes can be tweaked to limit filament use or completely skip the need for supports for example. It can noted that depending on a shape a support can take a non trivial time to remove, and that its removal could also result in damaging the print.

Each cross section is printed with ridges/fingers/ribs. These are baffles and they act to trap stray light rays or reduce the energy in the stray light ray by bouncing it around some before it gets to a persons eye or a camera / imager. You can see some rough sketches that were turned on where ray tracing was done manually to find a good enough configuration. These rays could come from artificial light sources and other sources that might impact image quality. Telescope builds in this class are typically done with plain cardboard tubes which are then sprayed with a matte black paint. Since I was 3D printing this I had the ability to go beyond this and add additional complexity.

The parts are largely printed without supports. Supports were manually added in a few spots. Telescope was constrained in size by what I could fit standing up on the printer. So all of these units (except for the eye piece are also a single print). Removing the tube and having it glued in allowed for build test and design iterations that did not need to wait on a 18 hr print, also reduced filament consumption, and allowed for test prints in between the batch prints of the other sections.

First image notice failure on bottom corner. This is and earlier section. Middle shows initial test fit of one of each section and a collimation tool to evaluate alignment and adjustment work flow. The third shows a section in progress.

This is using my phone in a mount. Mount is not steady enough to get stars or planets really well. The blurry shot you see is of Jupiter and its moons. By eye you can make out that there are bands of clouds and clearly see the moons. Capturing this level of photography is an area of improvement that is needed, but getting camera just for the telescope was not in budget for this effort. However, I am pretty pleased with the results of the moon and this setup. Cell phone sensors have come a really long way.

On a camping trip in the Comanche National Grasslands in Colorado. This area featured really low light pollution and clear horizons. No forests or mountains and you can see for miles and miles on clear day.