This week the main focus of our research was the movement of the ROV. We have decided to use DC Brushless Motors as they a water resistant so will work fine in the required environment. We have ordered a motor to test the gearing we will require as well as how well the propellers work. Its specs are below:
Rather then making our own propeller we have decided to download one off of GrabCAD. This will save us a lot of time compared to making one from scratch due to the number of calculations we would need to make as well as repeated testing to make sure the design functions. The CAD is shown below:
We are planning to 3D print 5 of these propellers each with a different pitch to find the best one to use on the ROV.
Finally we looked at what type of gearing we want to use. We concluded the best would be worm and wheel gearing as this will reduce the size of the gearing system. We are looking for an in water RPM of about 300-400, which will require a gearing ratio of 1:10-20. The RPM will be reduced in water, so testing it is highly necessary for these calculations.
 https://grabcad.com/library/5-blade-propeller by David Thomas, Uploaded: August 26th, 2011. Access date: 5/10/16
 https://grabcad.com/library/marine-propeller by Chao Wey, Uploaded: August 17th, 2011. Access date: 5/10/16