Dumb prop question.

fiveoboy01

fiveoboy01

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I see SPOH numbers for fixed pitch props.

What's involved in overhauling a fixed pitch prop? Can't be that much, with no moving parts. New hub mounting bolts? Dressing out dings? Paint?
 
I think they just sand it and balance it. right?
 
Profile the airfoil, correct pitch and track deviations, balance.... There are a finite number of times it can be done before the prop doesn't have enough meat on the blades to meet spec. In that case going from an old toothpick to a new prop can make surprising performance improvements.
 
To expound on Stewart's comment, the surface is ground to relieve stresses (in addition to dressing any other damage). Of course it also includes repainting the blades after this to avoid corrosion going forward.
 
The McCauley prop on my Tiger, which worked and looked fine, one time was ruled "out of limits" when checked. Replaced with a Sensenich which had the side benefit of removing a yellow arc on the tach.

Old prop is now hanging in my living room as a clock!

http://flic.kr/p/oHhJV3
 
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The newest guy in the shop takes a 7 inch disc grinder with a sanding disc and goes to town. When it's all sanded down it's measured. The shop then calls the customer and tells them that the prop doesn't meet specs and sells them a new one.:lol:
 
Not trying to hijack here, but seems to be close enough on topic:

What do you clean the prop with? Can you wax it?
 
floatplane guys usually wax the prop to protect it from water erosion. on a windy day with choppy water the prop takes a beating. on tires I occasionally run my window cleaning towel down the prop blades using whatever I use to clean the windscreen like Plexus or Pledge.
 
Never overhaul a fixed pitch prop, If you doubt the condition, send it in for an IRAN.

To overhaul, all the anodizing must be removed, the blade profile matched checked for cracks, blade pitch matched, and re-anodized, and refinished.

To IRAN is just that, the shop will strip, inspect, check for cracks, match profile and pitch, refinish and return it to service.
 
Tom-D said:
Never overhaul a fixed pitch prop, If you doubt the condition, send it in for an IRAN.

To overhaul, all the anodizing must be removed, the blade profile matched checked for cracks, blade pitch matched, and re-anodized, and refinished.

To IRAN is just that, the shop will strip, inspect, check for cracks, match profile and pitch, refinish and return it to service.
Click to expand...

It's about $800 to overhaul a fixed pitch prop in my neck of the woods
 
1RTK1 said:
It's about $800 to overhaul a fixed pitch prop in my neck of the woods
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Might ask for additional paint or info where to get it for touchups just because. They might throw in some at no cost.
 
Tom-D said:
Never overhaul a fixed pitch prop, If you doubt the condition, send it in for an IRAN.

To overhaul, all the anodizing must be removed, the blade profile matched checked for cracks, blade pitch matched, and re-anodized, and refinished.

To IRAN is just that, the shop will strip, inspect, check for cracks, match profile and pitch, refinish and return it to service.
Click to expand...
So the only difference is the anodizing?
 
I provided the Shop with RPM numbers on the prop as there is an acceptable range and the ability to tweak the prop for performance reasons. I took a set of readings using the A&P's tach. Static run up, take-off ground run RPM and climb RPM. After my RPM checks I removed the prop and found the prop model number and serial number did not match the logs. Different prop than came on the plane (Cessna 150 Aerobat) Fortunately, it is an approved prop.

My prop is going in for an IRAN also but I am getting the prop re-pitched.
 
It's also amazing the number of planes flying around without a computer balance done on their aircraft. One of the best bangs of the smallest bucks out there.
 
James331 said:
It's also amazing the number of planes flying around without a computer balance done on their aircraft. One of the best bangs of the smallest bucks out there.
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It's not something automatically done with a prop overhaul?

What's the cost, and how often should it be done if you want everything to stay vibration free for the most part?
 
I'd say when you add something diffrent that rotates.

Or even re install a prop.
 
A true prop overhaul includes static balancing. Dynamic balancing for an installed prop has a couple of sensors attached while the mechanic has you run the engine at various RPMs. He'll adjust for vibrations by stacking washers behind screws on the spinner backing plate. Some guys think it's the cat's meow. I've had it done a few times and haven't recognized any advantage. My current engine and 3-blade have been tested a couple of times and need no washers or adjustments. I suppose that's the best I can hope for.
 
fiveoboy01 said:
I see SPOH numbers for fixed pitch props.

What's involved in overhauling a fixed pitch prop? Can't be that much, with no moving parts. New hub mounting bolts? Dressing out dings? Paint?
Click to expand...

Strip, inspect, check/reset for all dimensions, repair repairable damage, dress, repaint, rebalance.
 
There are a lot of posters here that need to Read the overhaul manual for the 4 different prop manufacturers.


They are different.
 
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