41.2" Newtonian Telescope - page two

And we ground and we polished, then we did it some more. The only way that a mirror of this size can be hand polished is by a team of people, dedicated people. Because of the need to do the grind and polish routine three times (remember that lousy piece of grit in the second session!), the Hercules team was more dedicated than usual.

It takes two people to work a polishing tool this size. The adhesion of the tool to the mirror surface is pretty high due to the water and fine polishing compound. We usually had four to six people at a polishing session (we consumed about battle cruiser full of pizza during the project). Each polishing team would work for about half an hour, just enough to feel the strain, but not enough to wear anyone out prematurely, before trading off to the next team. In this manner, we were able to do 6-8 rounds per session.

The motion of the polishing/grinding tool over the mirror is critical to the process of creating a high quality, that is highly polished, surface. Fortunately, getting the right motion isn't really difficult, it just takes a bit of concentration the first few times you try it.

In order to avoid creating patterns on the mirror surface, it is important to turn the tool about a third of a turn while pushing it across the mirror's surface. This is done while walking around the mirror. So, the partners move around the mirror, pushing and turning the tool all at the same time. The idea to keep in mind while moving around the mirror is that each revolution should be different than the last. Remember to keep the surfaces wet and to check the polishing pads from time to time. Do pay close attention to keeping everything very clean.

The mirror box setting in the rocker box shortly after completion. The roller bearings and brackets can be seen below the altitude bearings. The altitude bearings are faced with 1/16" stainless steel. On the other side, one of the bearings is substituted with a friction drive shaft.

My friend Paul Wicklund had this plaque made as a finishing touch to the project. Paul shared many hours of his life to help bring Hercules in to being. I was touched by the plaque, and I'm very grateful to Paul and many others for their time, effort and friendship.