Foldout and container base for Hadley telescope

NOTE: this project is based around M4 hardware, I release the CAD if someone is interested in making an imperial conversion or other tweaks, but I conceived this contraption in a very non linear way and the Fusion360 timeline reflects it… thread in my brain processes at your peril ;)

This is a fold out pedestal for the standard Hadely telescope rocker base (Some stiffener like these are recommended), it's main features are:

• Large base without being overly cumbersome thanks to the fold out legs design

The default 220 mm size is meant to fit on an Ender-3 size bed so that about anyone can print this. The downside is that the corners of the rocker remain floating. That is not an issue in my tests but your mileage may vary. 

An optional 280 mm version is also provided, as well as a 280 mm top for the 220 mm barrel, as an in-between solution to save plastic if you do not need the extra space… or in case you have aftertoughts and dont want to reprint everything.

The blocks in the base have an 8 mm hole to accept 3 springs which give stiffness to the fold out legs, If like me you ordered a baf of 10x 3d printer bed levelling springs for the telescope mirrors, you should have 6 lying around anyways.

The rest of the stiffness is provided by the brackets: slide them in from the bottom with the legs closed, they have room to move out of the way of the legs opening, open the legs and press the brackets down in their slots.

It is easyer done than said, here is a video :

• Space for storing stuff (eyepieces, tools, chocolate, the pedestal's own brackets…) or even just to fill with ballast

The top, bottom and barrel are separate pieces to allow for barrels of different height to suit your needs (and changes of mind!)

The barrel can also be eschewed entirely if you prefer (more on this later).

I pre-generated barrels of 50 mm (for the 220 version) 60 (280mm) and 100 mm (both versions), and the matching brackets for the two diameters, and you can generate more by changing the barrel height parameter in the cad file, just pay attention to the bracket sketch that likes to do funny stuff and I cannot nail down why.

In my 220x50 barrel I was able to fit:

• Spare eyepeice
• Open Ocular 2 adapter
• Micro 4/3 camera adapter
• Allen key
• …and the three brackets of course.

• Smooth rotation of the telescope while also somewhat dampening drift 

On the collar, the small groove is meant to ease the application of a couple rounds of teflon tape (I didn't do it on mine).

On the flat face, the grooves reduce the contact surface with the rocker and are a snap fit for some lengths of bowden tube which decreases friction even more. The fit is tight, press down the bowden tube with the help of a spoon handle as it goes around the plate.

Both are entirely optional, I recommend to try and see what you need/like best.

• Modularity to allow a few different configurations.

In addition to the different diameters and the optional large top for the 220 barrel, there is also the possibility to assemble the top and bottom back to back, via the cutouts in the bottom which are meant to accept both nuts or screws, so you can exclude the barrel altogether and have just a flat dish (no brackets for you then, but it should not be much of an issue, worst case it sags 2 mm and touches in the center as well as in the three leg tips.

The lid exists in three variants, a standard one, a slim one and a deeper one with a handle which can be used to carry the pedestal (it is held by the thread of the lid so trust delicate contents to it at your risk).

I generated the lids in different tolerances, try the one that fits better. Keep in mind that the lid does help keeping the telescope down, and therefore stable, it is not crucial but it is not just decorative either.

• Tolerance of mismatched screw sizes, it is literally meant to soak leftover screws and nuts.

Most of the couplings are meant with M4x12 screws in mind and regular M4 nuts, except the 6 screws holding the legs which must be at least M4x20, however, the design is deliberately tolerant of longer screws and mismatched nuts so if you have leftovers you can use this project to eat them up.

There are cutouts in the bottom so that if the screws holding the feet stick out a bit, the leg will still fold.

The pits in the bottom are a little extra recessed so that even if you use a longer screw it will not stick out and scratch what's inside the container, and if you have leftover nylock nuts to spare you can use them here.  

The screw holes in the barrel run across all the height of the wall, so you can use any length of screw you want.