This is something most people don't know, new props not balanced, but it's the first thing they ask for when you repair their prop. Keep up the good work and videos.
Bought brand new in the box AC Delco Rochester 4bbl carb still in the wrap. Looking right through the plastic, found a broken lever and did not bother to mess with it. Dealer had another one the next day, worked perfect. Just because it is NIB, it does not mean it is OK.
When balancing RC airplane props the hub often needs balancing also. To do this I first do exactly as you did but then I put the prop in the 1/4 positions and see if the prop rotates. In essence, a well balanced prop will stay still no matter what position (all through the 360 degrees). Nearly always the hub needs balancing. The hub is ground slightly to balance. Does this make sense? Good video BTW.
mkl3opt I have been an RC aviator long before I got a boat. I feel like the years I've had balancing rc airplane propellers puts me at an advantage at understanding boat propeller balancing fundamentals. Just finished balancing a 3 blade bronze propeller for my '60 Merc 400
What causes a boat to slip off pad at top speed and lose speed but hold the same RPM's. I had my prop fixed at a prop shop and when it reaches top speed I can feel it slip and lose 4 to 5 mph. It is a T-1 27P Vmax prop vented on a 21i class skeeter with a 2006 300 HPDI at 3.5 below pad. None of my other props have done that including the same type prop that came on the boat.
First of all new stainless propellers are balanced in a machine at its operating rpm. This make them look unbalanced when checked with a 1960 method. Secondly they are cnc machined on the front side to prevent kavitation. You just unbalanced that propeller and grinded on the wrong side. This will cause wear to the sprockets at final gear and its bearings. + higher fuel consumtion and slower speed of the boat.
For one, the name is spelled Philo Beddoe. For two, even at 87 he would stick wipe the floor with you. And three, an out of balance prop will shell your outdrive whether the prop is new or old. If you buy a new prop and it is not balanced, then I guess you can just keep shipping it back until you get lucky.
Thomas Asseryd you are absolutely wrong on all aspects of your comment. First those props are cast and are hand ground and finished in a vibratory polisher. Secondly a prop out of balance at any speed is out of balance period. You don't operate at the same rpm on every application so it has to be balanced at all speeds, even slow. I know for a fact that most prop shops still balance their props in the same way ( 1960's method). Third all props are balanced on the negative side of the blade and then repolished. Acme propellers actually balances them on the negative side of the blade and then leaves the grind marks. Fourth cavitation is spelled with a c. We appreciate your views and comments but after 44 years I don't think we need your advice and I'm sure most of our clients would agree.
