02062013, 08:31 AM  

correct. the tips of the prop go super sonic. larger props take fewer rpms to cause this and flexable props make it easier as they flex and the motor has less resistance to reach the higher rpms. Below is how to figure tip speed and how to guage what you can do with a motor to prop it correctly. The problem is finding out what the motor is capable of turning with out effecting the spool up time and the rpms to the point it is no longer effective for what we are doing
http://www.pponk.com/HTML%20PAGES/propcalc.html or 1 Calculate propeller tip speed in miles per hour by multiplying prop diameter, RPM, and the constant 0.002975. For example, 32 inches multiplied by 6,800 RPM and 0.002975 equals 647.36 miles per hour. 2 Calculate the speed of sound for the given ambient temperature by adding 460 to it, taking the square root, then multiplying by 33.4. For 59 degrees Fahrenheit, add 59 and 460 to obtain 519. The square root of 519 is 22.78. Lastly, 22.78 multiplied by 33.4 yields 760.9 miles per hour. 3 Divide the tip speed in miles per hour by the speed of sound. In our example, 618.8 divided by 760.9 gives you a mach speed of 0.813. 
02062013, 09:05 AM  

Quote:
Gives a very good indication to pilots. Wayne 

02062013, 09:55 AM  

Your absolutely right, it does get old. Rip em up on your home turf is what I should have said, but when at an event with a gagillion people have diligence and respect for your fellow man!
If you guys see a halfa$$ed hybrid with ugly wrinkled covering that'll be me! Come on over and hi! 
02062013, 10:25 AM  

I enjoyed the machine gun vs rc plane vid. I would kill, to get to run about 6000 rounds thorugh the minigun. Dillon builds awesome weapons for sure. And the mg42 was bad azz too.
I have flown the DLE 170 on stock mufflers at Joe Nall , no problem. Cause I used the throttle stick with forethought. 
03222013, 05:23 PM  
United States, GA, Atlanta
Joined Jan 2012
85 Posts

Quote:


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)  
Thread Tools  