Duncan Kitchin OMSI Astrophotography Conference 2011 BUILDING A TARDIS MICRO OBSERVATORY

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Frank Gallagher
5 years ago
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1 Duncan Kitchin OMSI Astrophotography Conference 2011 BUILDING A TARDIS MICRO OBSERVATORY

2 Overview Objectives The need to minimize setup time Analyzing where the time goes Solution outline Constructing a permanent pier Components Planning Construction A weather cover First iteration A shed that's bigger on the inside Remote electronics box Requirements -emulating a permanent configuration System configuration Designing a wiring loom for fast setup Optics Everything in one Wrap up Demonstration (video)

3 Objectives Motivation #1: Setup time Multiple trips carrying heavy gear Set up and roughly align tripod Mount, counterweights Scope(s) Cameras Big mass of cables Polar alignment Major time sink particularly if drift aligning Can occupy ½ hour to an hour Still might end up with poor alignment (particularly for narrowband imaging)

4 Objectives Motivation #2: Consistency Risk of getting something wrong with the setup Dismantling/reconstructing setup leaves many opportunities for screwing something up If it s already dark by the time you notice, the night could be a write-off Changes to electrical configuration can be problematic Something as simple as changing a USB port can change the system s behavior

5 Objectives: Bottom Line Setup time Start at minutes Target is 5 minutes Consistency Multiple sources for wasting imaging time Make the setup exactly the same every time

6 The Plan Big item #1: mount setup Fix this with a permanent pier No tripod to set up If the mount head stays outside with a cover, can drift align one time and keep it aligned Much less to carry outside Big item #2: electrical setup Fix this by putting everything in one box A permanent electrical setup that moves in one go Consistent setup Less to carry one trip Big item #3: optical setup Fix this with a means for storing the whole optical train intact Telescope and cameras semi-permanently screwed together Stores in a big Pelican case

7 Constructing a Pier Components Design Planning Construction

8 Components Sonotube They have uses other than making Dobsonian telescopes 12 diameter recommended Make some wooden bracing Rebar Large number of 2ft sections, wired together Rebar extends all the way up the pier 14 x 80lb bags of concrete Renting a mixer highly recommended Be sure to wear a face mask! Pier top plate Many options Dan s Pier Top Plates ( recommended May not be the cheapest option, but very solid and great quality Adapters available for many mount types

9 Design Depth of footing will depend on the depth of the frost line Depth to which the ground may freeze Must go at least 6 below this point Failure to do so will cause frost heave Washington county frost depth is square hole is adequate for a short 12 pier Height of concrete is about 20 above grade Implies approximately a half ton of concrete

10 Design

11 Planning Check for underground obstacles such as utilities Mark the extent of the hole with white paint Call the utility notification center between 2 and 10 days before digging Consider the time of year The clay in some parts of Washington County can be rock hard in the middle of summer

12 Construction

13 Construction

14 Construction

15 Construction

16 Construction

17 Construction

18 Construction

19 Construction

20 Construction

21 A Weather Cover First iteration A bag or soft telescope cover Adequate solution for short periods Watch out for dew A more permanent solution A shed that s bigger on the inside Trapped mass of air reduces chances of dew Space to install a light bulb for warming

22 The TARDIS Micro-Observatory

The Inspiration http://doctorwho.bbcamerica.com/ zir.

23 The Inspiration zir.com This file is licensed under the Creative Commons Attribution 2.5 Generic license.

31 Remote Electronics Box The remote box contains everything to control the telescope Mount Camera Autoguider Focuser All cables Several design iterations to yield a satisfactory result

32 Requirements/Motivation Keep everything in one place Many components & cables needed Easy to lose or forget something critical Ease of transportation Consistency of configuration Serial ports number changes if USB port changes USB ports some cameras don t like change Remote operation Operate from a warm home / trailer Wireless useful, but not essential

33 First Configuration Network USB hub Belkin F5L009 5 USB ports CAT-5 Ethernet cable < $100 Other models available Members at Cloudy Nights forums report success with Icron Ranger ( More expensive -> $300 for multi-port version WiFi Access Point One I had lying around

34 First Configuration WiFi AP USB Hub USB-Serial Adapters Power Strip Level Shifter

35 First Configuration Assessment Keeps everything in one place All components fit in a box Single power cord powers everything on Wiring loom with all connectors Easy to transport Configuration is consistent Wiring loom ensures specific USB/serial connections to specific destinations Remote operation Workable, but presents reliability issues over wireless Glitch in link performance kills autoguider

36 Current Configuration Similar to first configuration, but instead of USB hub, there is a nettop PC in the box Acer AspireRevo AR1600 Intel Atom 1.6GHz / 1GB DRAM / 160GB HD $200 with Windows XP installed This model no longer made; current model ~$325 Operated remotely by VNC installed as a service Many different versions available This setup uses TightVNC Optimized for bandwidth-constrained links

37 Current Configuration WiFi AP Nettop PC USB-Serial Adapters Power Strip Level Shifter

38 Current Configuration

39 Current Configuration Assessment No more reliability issues Capture & guiding is completely self-sufficient If the wireless link fails, no problem; just reconnect and everything is still there Note that, because of the setup, this remote PC is never connected to the Internet Doesn t get automatic updates Seems to run strangely quickly for such a lowpowered PC (boots Windows in a few seconds)

40 Optical Configuration Greatly reduced in size Off-axis guider is a huge improvement Built in OAG in QSI camera Many other options Weight, complexity & space reduction Threaded adapters Worth every $ of the 4 x $150 I paid Takahashi Big Pelican case Makes it unnecessary to assemble or disassemble the imaging train in almost all circumstances

41 Optical Configuration

42 Optical Configuration

43 Wrap Up Hit all of the big areas that expend time: Mount alignment set up once, alignment is good for days or weeks Much less to carry out down to 2 trips Setup is consistent much less chance for errors, less wasted time fixing configuration bugs Net: set up in 5 minutes

44 Demonstration

45 References Icron Remote USB Dan s Pier Top Plates TightVNC Acer AspireRevo Utility notification

Paramount Robotic Telescope Mount Specifications

Paramount Robotic Telescope Mount Specifications The Paramount Robotic German equatorial telescope mount is available in three models to suit your needs. The portable Paramount MYT carries 10-in. (0.25