Last year, our telescoping arm used no pulleys and was pretty easy to fabricate. We used three different sizes of square aluminum tubing that folded in on eachother to fit within the dimensions allowed. We used a van door motor directly connected (as can be seen in the photo below) to rotate out to full length. I don't think the van door motor will cut it this year lifting those 9 pound tetras, but it could be possible to do what we did with the arm setup of the new transmissions (outlined in "Guidelines, Tips & Good Practices" available in the manual section of the FIRST website) and lift the tetras. I haven't done the calculation yet.
There is a good picture showing how this works, but I don't currently have access to it. It's very simple.