Woofing in corners..

[Joe Yau]

Just wondering if there's a way to eliminate or minimize the "woof" prop noise in corners with 2-blades (like apc 13x5.5EP) ?  and would using 3-blade help to smooth it out?

Thanks in advance

[Igor Burger]

and not only that, 3bl will also save your bearing :- )))

[Dennis Toth]

Joe,
One option is to add a small speaker and sq wave generator to make it sound like an ST 60. All kidding aside, usually when a prop is making noise it is a tip shape problem. I have modified numerous props and one way to tell how good it is is to put it on an electric. The best tips for noise are the shaped like the APC props, the Top Flite power tip is also good. For pulling power the square tip seems to be on top but will make some noise in the corners. One trick to try is to sand the last 1/16" of the prop tip angling from the bottom to the top, this is a mod that Hal DeBolt did on some racing props and it quites them down and they pull better (works on 3 blds too).

Best,        DennisT

[Crist Rigotti]

Just wondering if there's a way to eliminate or minimize the "woof" prop noise in corners with 2-blades (like apc 13x5.5EP) ?  and would using 3-blade help to smooth it out?

Thanks in advance

I solved my woofing problem by going to the thick hubbed version.

[keith varley]

I rather enjoy the "woofing" because it can be a learning tool.. It  is rather obvious when the corners aren't the same because the sound differs , so to me it is a learning tool.  Not that I do them all with the same degree of hardness, but I do take notice , and try.    That is probably another advantage of electric stunt , that hasn't been widely recognized.  Keith

[Larry Wong]

OK I had the same woofing on my plane, this is not my Idea but PTG's we put carbon Vail on both side's of prop. and it stiffen the prop  to stop the noise.

[James Strickland]

PTG's?

[Larry Wong]

PTG  Elroy's Dad ......    

[Joe Yau]

Some excellent ideas & infos.. Thanks all for the replies!  

 
Igor,  
That's assuring and makes a lot of sense.

Dennis,  
Thanks for the Prop's tip mod..  will have to give that a try.
 
Crist,  
Not sure which version that is, will have to look into it.
 
Keith,  
That's a good idea!  listening to the corners..
 
Larry,  
What type of adhesive did you use with the carbon vail?

[Larry Wong]

Joe we use  Minwax Polycrylic clear gloss, (water based) but I'm sure clear Nitrate, or Butyrate  will work

[Howard Rush]

Just wondering if there's a way to eliminate or minimize the "woof" prop noise in corners with 2-blades

Joe, you are borrowing props from the wrong people.  Mine woofed until I borrowed a prop that had been well balanced and pitched.  The woofing was much reduced.  Don't borrow one from Chris Cox.  I did, and it was substandard and a significant woofer.  Chris got the substandard one from me before I borrowed it back.  Hope this helps.

[Dean Pappas]

Hi Gang,
Motor mount flexibility can also cause wow-ing or woof-ing in corners.
Prop and mount flexibility can combine to rip the mount out of the plane altogether.
There were several long threads about this several YEARS back (yes that amazes me too) and I think you'll find a lot if you search for both words.
take care,
 Dean