Remote Robotic Observatory v3

[SamAndrew]

Hello everyone and welcome to my 3rd Observatory thread; I've been iterating and improving on the previous one over the past year. The process has taken a bit longer than expected, as last January I was blessed with my first child, Freya! and parenthood has consumed most of my free time (as expected!)

The previous build has surprisingly been very succesful, and has only been hampered by the terrible weather we've had for the last several months here in the UK. Thread located here:

I wanted to improve on the hinge design, and eliminate the risk of the two actuators on each door opening at different speeds. I also aquired a new Mesu 200, so it needed to accomodate the huge counter weight bar; and I also planned to side by side mount 2 scopes. Below are the pictures of the concept with 4 inch and 5 inch refractors piggy backed:

More detail to follow.

[SamAndrew]

My initial aim was to replace my existing EQ6+Quattro setup with this new build and the Mesu and 2 x Quattros in a side by side configuration, and bring the eq6 back home and then build another smaller version for the Eq6 and my Esprit 100.

I bought two 24V, 4000N actuators with hall sensors for positional feedback, and got these working in tandem using BTS7960B motor drivers and an esp32; After some pondering I figured it was easier and cheaper to modify the design so that I only need one actuator per door. I may revist this idea in the future if the design grows in size to house larger scopes.

 This time around I went for an aluminium structure that is bolted & rivited together. The skin is aluminium composit board, which is often used for cladding, but also finds use in sign making and printing.

 For remote operation, power is controlled via wireless smart plugs that can be toggled via a mobile app - so far I've had no problem with 2 of these over the past year in the existing setup. As they are wireless I have a wireless router inside the obsy to maximise signal strength.

 I use a Dell optiplex micro PC running Teamviewer and all the usual astro programs - Teamviewer has only let me down once in the current observatory, but thankfully that was while i was on site; I had to sign into the application again after an update which required plugging a monitor into the PC.

 The build is now complete, and I'm going through some initial trials and tweaking on the patio in my back garden ahead of relocating it to the remote location. There are a few bits still to iron out.

 As I was building it, I've had a few brainwaves on how to further improve the design, so the next version is already in planning, I've also recently aquired another scope - the Altair 130 in the renders above, which is a bit of a tight fit.

 Pictures to follow.

 

[SamAndrew]

It's still a little rough around the edges, I plan to strip it down and tidy things and give it a polish. The garden needs a bit of a tidy up as well! The doors can be detached for easier access (and transportation), but due to their size it's a bit tricky - something I've improved with the next desgin.

The aluminium panels were routed and then folded to form the shapes required, but getting two triangular doors to align perfectly required some precision. There's some flexibility in the doors that means as they meet in the middle, they bend rather than slide together perfectly, so I plan to rectify this with some more L angle bar to stiffen the sides up. To combat this in the next design, the doors will be rectangular again, but inclided along the hinge to match the lattitude.

The 130mm scope just about fits, but wasn't part of the original plan, so we'll have to see if there are any clearance issues once the camera is attached and at focus - I suspect I now won't have the meridian flip free experiance I was planning.

Will update as I do some more testing. I want to write an ascom controller so it can be opened and closed automatically after the scope is parked up. I also plan to install the HiTec Astro Weather Deluxe on the back. If I continue to have issues with the doors sealing, I may add some elctromagnets to pull them together over the last few cm.

Thanks for reading, hopefully inspires someone else to try something a bit different

Cheers

Sam

[Nigella Bryant]

How secure is this, I had my shed broken into many years ago and had my 12inch SCT stolen, never recovered but thankfully it was insured. I had three lock's on the door as well. Happened when I was away on holiday. 

[SamAndrew]

Yep good point, another consideration for the next design. The advantage this has is it's not obvious what it is, the previous design looked like a bee hive, this one more like an electrical substation. With some appropriate "danger of death" signs, it might put someone off poking around. The hinges and metal frame are strong, the door panels are not. In the closed position if you bent the door panels back, it would still be tricky to extract the mount. I will look into some security nuts for the Mesu, as that is the most valuable bit. Nothing is secure unfortunately if a thief comes equipped and is determined; I think this stands more chance of going un noticed than a dome.