Pin positioners for hub extension.......Excuse my ignorance, but what are the extra holes for? (frontside of prop only)
View attachment 42935
Pin positioners for hub extension.......
I don't buy that theory in this case. Fixed pitch props are balanced by removing material or by screwing weights on the side. These two holes are the same on opposite sides of the hub.Balancing
I don't buy that theory in this case. Fixed pitch props are balanced by removing material or by screwing weights on the side. These two holes are the same on opposite sides of the hub.
That is possible, but have you seen one drilled in a similar manner for that purpose? I have not.But are they the same depth. Another possibility would be fixturing for the machining operations
Is this a 1A175GM82-4X ? If so then perhaps they are tooling holes for some new CNC propeller making machinery? The new props are very precise.View attachment 42943
My Borer prop has the holes. I thought it was typical.
Once more: What is your model number? go to: https://www.faa.gov/The prop in the picture I posted has balance weights attached already. If the extra holes are for machining, it sure is a shame they are on the front side.
Thank you, Direct from the horses mouth is the best answer. They must have changed some of their manufacturing processes. It does seem strange that two identical holes would be placed opposite to each other and then say it was for balancing. Maybe it is just a place to put some lead if needed?I purchased my McCauley 1A90CF7538 in 2007. It has the same holes. When I unpacked it and saw those ugly holes I called McCauley. The guy I talked to said it was for balancing.
Thank you, Direct from the horses mouth is the best answer. They must have changed some of their manufacturing processes. It does seem strange that two identical holes would be placed opposite to each other and then say it was for balancing. Maybe it is just a place to put some lead if needed?
More than likely they would use Mallory.Yes, my understanding is that the holes are for future balancing after the prop leaves the factory. Not sure what material is used to add weight. Wouldn't be surprised it the EPA has banned lead for that purpose.