Computer Control of the Dome

Over the past few posts I’ve been using the expression “We have done XYZ” a lot rather than “I have done XYZ”, which as any PhD supervisor knows probably really means “My student has done XYZ” at least to some degree.  In this case to a very large degree the vast majority of the ongoing work in the dome has been carried out my my second student intern Sunayana Bhargarva, who has been working for twice as long as Edo officially did. Unfortunately we haven’t had too much in the form of pictures or videos of her to put up here (careful readers will have spotted her in some videos).  Mark my words however the greatest effort and momentum over the past two months in this project has come from her.

She has been trying to get the dome to rotate 100% reliably, we are not there yet but we are on the way:-

In the early stages of getting the dome to rotate via the motors, after prolonged use, the cogs would start to disengage with the timing belt, generating horrendous noise and no rotation. This was, in part, due to the cylindrical structure of the motor, causing it to slip on the wooden shelf and no longer maintain the angle needed to grip the belt.
This problem was attacked by Sunayana using some high grade emery paper, slotted under the bottom of the motor and inside the necessary jubilee clips (anyone know why they are called that?), to provide enough friction and control against any unwanted rolling or slipping. Additionally, wedges were placed underneath the wooden hinges supporting the motors to achieve maximum contact between the cogs and the belt. As the motor shelves are tightened in their positions, the contact is most strong along the bottom half of the cog. However, by reinforcing the wooden hinges with wedges, the entire system is pushed up slightly, allowing the top of the cog to also make continuous contact with the timing belt, making rotation smoother and less prone to jarring.

So that’s pretty nasty messy frustrating stuff.  Something more satisfying is what else she has been doing and that is getting the whole dome to rotate from a computer, which has involved a complicated set of relays, but which she has got working now.  I’ll let her explain:-

Now that the computer can move the dome, we hope to get the dome to track the telecsope automatically, but we’ll show you when we get that to work.

You should probably also know that Sunayana is quite an accomplished musician and successful poet, here she is reading one of her poems:-


Edo’s funny video and Bill the technician

So Edo had to make a blog for his summer project and as part of it he did this, which, I admit, is berlusconic genius :-

Apart from that I was pleased to see that he had also got videos of one of the most important people in getting the telescope up and running, that is Bill Luckhurst.  Bill is our research technician, he maintains the sensitive equipment the serious experimentalists in our group use, the only part of it that I really understand is that he maintains the scanning electron microscope which is used by all the nano people so they can figure out what they are doing.  They’re all doing very small stuff, so they all need to use this device quite often.  But I know for a fact he does a lot more than that, because basically people ask him to do whatever stuff they can’t do, LIKE ME.  I always felt a bit conscious of recording him for the blog but luckily Edo didn’t mind, and since this blog is a record of the dome being brought back into use, I’m pleased we have these, you can see them at the bottom of this post.

Meanwhile, we’ve been trying to make the rotation more reliable, it does OK, but it keeps catching at certain points.  We’ve been experimenting with different springs etc etc…  We’ve also made progress getting the dome to track the telescope, but that’s for later.

With regards to observations, we’ve been out, but there are no planets at this time of the year apart from Saturn close to the horizon.  In London we can forget anything close to the horizon, the people at the widescreen centre who supply our gear tell us to forget anything less than 20 degrees, and if you see how Saturn jumps around on our screen when you try to image it in its current position you can’t disagree.  We’ve got the filters up and running but since then we haven’t had any good nights, we’ve had cloudless nights but not without a thin veil of high altitude cloud which means we can’t see any galaxies or nebulae, so no action.  During these failures we are figuring out how to work things a bit better though, so when we do actually have good seeing I hope we will have stuff to share with you.

In the mean time, here are some videos from Edo (i.e. I’m not responsible) of Bill:-