Safety Comes First
MORE ON PROPS. A recent letter from Jim Newman ("Hints and Kinks" editor for Model Airplane News) enclosed a copy of an article which had appeared in another model magazine, describing how to make a four-bladed prop out of a pair of glass-reinforced two-bladed props. Neither Jim nor I feels that this is a safe practice. In fact, we strongly recommend that you do not attempt such an undertaking. Why? Because we are concerned that the procedure described in the article will result in a prop with a hub of questionable strength which could allow the blades to fly off when the engine is running. The article explained how to cut away half the thickness of each of the two-bladed prop hubs (cutting one prop from the front and the other one from the rear) in order to create a lap joint at the center with a hub thickness equal to that of one of the original props. Slow-curing epoxy glue is used to secure the joint, and the hub of the newly created four-bladed prop is then wrapped with carbon fiber soaked in more epoxy for reinforcement.
Safety Comes First
TRAINERS-basic, advanced, and beyond. Although there are about 450 people at my place of work, it seems that I am the only one who counts model aircraft as a hobby. As a result, in the weeks just prior to Christmas (I'm writing this column on January 2) I frequently will be asked for my recommendations on what model to select for Uncle Charlie or Cousin Jack, etc. This year was no exception, since one of my co-workers sought my advice on a second model for his father-in-law. Last year I had been asked for my suggestion for a first model for this person, and had come up with a list which included a Goldberg Eaglet, Sig Kadet, and PT-20 or -40. They chose the PT-40, and apparently father-in-law was successful in learning to fly with this, his first RC model.
