Data Log 6 - 

 

Today we were ambushed. Men with grins and guns, bald heads and suits stood there, waiting for me to reach the base. There were countless of them, all connected with each other via wireless speakers, they must have tapped into the KCL network and were planning to bring the corporation down from within. I slowly walked through the desolation which lay before me; cables, lighting equipment, cameras, make up boxes... all was set for the set. And then action! The thief in a rugby shirt and beer bottle runs up the stairs, followed by men in black suits and guns , shots are fired, paintball snipers mimic the explosions by firing porcelain bullets on the walls, and all becomes a jumble of running, sweat, 'Cuts!' and professional parkour upon the roofs of the Strand building. With me running about with the windscreen wiper motors, I added an incongruent touch of sci fi action to the place. The film was entitled ‘Hendon’s Curse’ and for a whole three days they were to be my roof mates.

 

With the windscreen motors properly wired up we realised that different cables led to different rotational velocities, those which allowed a low speed rotation, hence a large torque, were the yellow and brown wires. Connected in series the motors would spin even slower, hence produce and even bigger torque. One of the issues was to find a power supply which could operate at a high amperage and a relatively high voltage. After meeting Daniel Craig’s look alike in the robotics department, a massive power supply was handed over to me. It could supply a whopping 40 Amps worth of current, theoretically, however it always seemed to stop at 12A when connected to the motors. The torque provided was so high that it became nigh impossible to stop the motor from performing its rotation, something which was previously achievable with the slightest touch of a finger when a conventional power supply was used.

 

Up until this moment we had no idea how much torque was required to get the dome moving, not even a faint glimmer of knowing which magnitude of torque was required. In the end I managed to calculate it by adapting the elevator-and-scale-experiment to this situation. I tied a string to the outside of the dome and stood onto a mass balance. I then stood on the scale and pulled the dome until it started to rotate. The reading on the scale decreased. The amount by which it decreased by was equal to the torque (when converted into Newton cm) needed to rotate the dome, when the necessary trigonometry calculations had been performed. This came at 15Ncm, and with smiles on our faces we realised that the motors could provide such a torque. 

 

Already a month and a bit gone. The dome looked half complete, we needed reiforcements. Out of the blue, here they arrive in the form of an intern who can actually sing. Sunayana Bhargava, a fellow soon to be third year student and friend takes on the challenge of finishing off what me and Malcolm started. From the very beginning she showed the same enthusiasm as I did in the first weeks of action. After building the hinged mechanism which me and Malcolm thought of, she went onto the coding aspect of the project, but it is best to read from Sunayana's data log:

 

Sunayana's own data logs:

 

Over the last few weeks, I have been wiring up both infrared proximity sensors to a circuit of four relays, connected to the motors, all driven by the monolithic Arduino Uno.  "breathes"

Using this equipment, the ultimate aim is to calibrate the telescope’s slewing motion with the motion of the dome, so the telescope may always point outside the hatch, unobscured. The Arduino code which necessitates this receives an analogue input from the sensors saying “obstacle detected.” The inbuilt ADC convertor in the microcontroller then processes the signal, and releases a digital output to the relay circuit, which automatically switch on the motors to rotate the dome, until the sensors no longer detect an obstruction.

 

The motors which are responsible for rotating the dome have encountered some recent jarring, and, over numerous rotations, disengage with the timer belt. They have now been reinforced using the following complex and sophisticated tools: emery paper (the bodybuilder equivalent of sandpaper) to increase friction between the motor and the shelf to prevent slipping, and lots and lots of wooden wedges to stiffen the mechanism entirely. It has proved to be a successful initiative thus far!