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DZ160 and 4-blade prop

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Old 07-23-2005, 06:41 PM
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PeterP
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Default DZ160 and 4-blade prop



Hi Don,

First of all congratulations for your 3rd place at the Nats.

I noticed that your using a 4 blade prop on your YS setup. Could you please shed some light on your setup and any benefits it provides. What RPM are you swinging?


Thanks again,


Peter
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Old 07-23-2005, 10:15 PM
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Don Szczur
 
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Default RE: DZ160 and 4-blade prop

Advantages were that there is no fear of missing the dB check during competition. I had to dial the 160 DZ down to 85 percent ATV to make sure it met sound requirements at the NATS last year flying a 17x12 two blade. I realized that they did not require the electrics to noise check at the NATS this year. Only 3 of us flying glow fuel. We were the only ones that had to noise check.

I decided on a 4 blade for noise, for speed control (it provides extra time in the down line humpty bumps, for example).

The 4 blade, finally, is cool. Lots of peopls ask about it. Kind of like high tech. (that's a more recent observation).

Do make sure you use a starter. If you do use a chicken-stick to start the motor, move your finger (or stick) out of the way 50 percent faster. I lost 1/4 inch off the tip of one of the blades when I was hand starting it earlier this season. Still flew ok for months after that. Just chopped took a quarter inch off the opposing blade. Call it a 14.5x15.5X 12. Flew great.
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Old 07-23-2005, 11:13 PM
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Default RE: DZ160 and 4-blade prop

Don,

Congretulations on the Nats.

I am also using the 4 blades 15.5 x 12 with my 160 DZ. It has good speed control on both level flight and down line. However, it struggles a bit on the upline, especially on the humpty with snap up. Have you try the 4 blades 15 x 11?

Also, I have notice the Japanese pilots have been using 3 blades on their DZs, and have just received the 15 x 13w from Central, can't wait to try it.

Adrian
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Old 07-24-2005, 06:53 AM
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Default RE: DZ160 and 4-blade prop

Hi Don,


Thanks for the reply.

What RPM is your engine turning. I assume your using 30 heli fuel?

What is the vertical performance like?


Cheers,

Peter.
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Old 07-24-2005, 07:53 PM
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Default RE: DZ160 and 4-blade prop

Hey Don,
I ran the same 4 bladed prop as you on the 160 and had some serious vibration issues. What are you doing to balance the prop?
Thanks
Greg Grigsby
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Old 07-24-2005, 10:40 PM
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Don Szczur
 
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Default RE: DZ160 and 4-blade prop

Vibration issues on the prop, I sand my leading, trailing, and tips. Vibration may be an issue. I just don't notice it much, although at about 1/8 throttle there is a bit of an oscillation going on, it seems to settle in and runs smooth above that throttle setting.

Now, I have noticed that on some of the APC props, the center hole is not exactly in the center. Check that, or try another one to see if its the same.

I use a nose ring support which is solidly mounted to the front of the fuselage. Again, this is the setup for the Brio. Someone, somewhere has the RPM settings for the 4 blade. I don't. I've never measured it but it sounds like its pulling it just fine. I've used the same prop most of the season on the 140DZ's that I've run in the Brio. The 160 provides a little more umph in the vertical snap and center humpty in the sequences.

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Old 07-24-2005, 10:44 PM
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Default RE: DZ160 and 4-blade prop

You are hearing this second hand, but I was told the 15.5X11 four blade has better vertical, but misses the pull right after the snaps at the bottom of the loops in Masters, for example. Anyhow, ask around, sounds like there are some new prop sizes out there both 4 and 3 blades that are working well.

I'm using Magnum YS DZ blend fuel.

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