Prop Rip

[Bunky.F.Knuckle]

Which would you think would be better biela 30x10 or mejzlik 30x10? I'm looking for fast spool up but trying to keep the rip under control

Neither. Go down to a 27x11 Falcon CF or a Mejzlik 27x12TH. By going up in prop diameter, you are making it easier to bark a prop. 30" prop on a 120cc airframe and engine is not the answer to prop rip. There is a diagram out there in cyberspace somewheres describing what most are trying to give you advice on doing. I will look for it and post it here. Again, 30" props are not the answer to prop rip. You could load it with pitch, and it will be stupid sluggish. Heed our advices, and try a Falcon 27x11 or the Mejzlik 27x12TH. Both will offer instant spool up and making it harder to rip the prop.

Remember back when you were a kid.... Had to get a switch out of the tree because you done something wrong...... I always went for the short ones, because they didn't hurt as bad. The longer ones hurt! You would try out which one you wanted to get busted with. The shorter one didn't make the "whhhhhhosh" noise, unlike the longer one.

Try this link too.... http://www.warpdriveprops.com/propspd2.html By saying keeping the tip speed under .7 mach is key for full prop effeciency.

 

[SlowHuck]

Remember back when you were a kid.... Had to get a switch out of the tree because you done something wrong...... I always went for the short ones, because they didn't hurt as bad. The longer ones hurt! You would try out which one you wanted to get busted with. The shorter one didn't make the "whhhhhhosh" noise, unlike the longer one.

Brilliant analogy!

 

[Twister]

Neither. Go down to a 27x11 Falcon CF or a Mejzlik 27x12TH. By going up in prop diameter, you are making it easier to bark a prop. 30" prop on a 120cc airframe and engine is not the answer to prop rip. There is a diagram out there in cyberspace somewheres describing what most are trying to give you advice on doing. I will look for it and post it here. Again, 30" props are not the answer to prop rip. You could load it with pitch, and it will be stupid sluggish. Heed our advices, and try a Falcon 27x11 or the Mejzlik 27x12TH. Both will offer instant spool up and making it harder to rip the prop.

Remember back when you were a kid.... Had to get a switch out of the tree because you done something wrong...... I always went for the short ones, because they didn't hurt as bad. The longer ones hurt! You would try out which one you wanted to get busted with. The shorter one didn't make the "whhhhhhosh" noise, unlike the longer one.

Try this link too.... http://www.warpdriveprops.com/propspd2.html By saying keeping the tip speed under .7 mach is key for full prop effeciency is key.

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Thanks for the info ( you brought back some painful memories lol ) so far I have been able to borrow props, i'll see if any of my club members have a 27x11 or 27x12

 

[Bunky.F.Knuckle]

My buds DLE 120 out turns my DA 120 on the same prop, Falcon 29x9. If you can't find a 27x11 or 27x12 locally, let me know. I have a Faclon 27x11 not on anything currently. I spent alot of $$ on prop over last winter, in search for the right prop for my flying style.

It's cold here in Ohio, so I'm in rebuild mode and doing maintenance on the birds that are flying.

 

[Bunky.F.Knuckle]

I'm having the same problem after mounting an MTW RE2 to my GP61. My club will have noise restrictions next year so I'll need a different prop. Fergus recommend a Mej 23/10 but that seems really small. What do you guys recommend? Here's a video from this weekend:

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Will they be enforcing a dB reading on the ground?

 

[Eric Anderson]

I'm not sure yet. I have the props narrowed down to a Falcon CF 24/9 or Mej 24/9th. What do you think?


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[Eric Anderson]

On of the clubs I fly at May be moving next to a golf course next year..... The other is like 98db


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[Decal Dennis]

Remember back when you were a kid.... Had to get a switch out of the tree because you done something wrong...... I always went for the short ones, because they didn't hurt as bad. The longer ones hurt! You would try out which one you wanted to get busted with. The shorter one didn't make the "whhhhhhosh" noise, unlike the longer one.

Lucky!!!....I had to get the big wooden spoon out of the kitchen drawer, man that thing hurt.

 

[SlowHuck]

Lucky!!!....I had to get the big wooden spoon out of the kitchen drawer, man that thing hurt.

This was my mom's "Weapon of Ass Destruction," minus the ball and rubber band, thankfully. Between this and dad's over-the-knee, bare-handed spankings, I would have ended up in CPS this day and time!

 

[TazmanianDevil]

Trial and error I guess. Nothing can defeat that.
If you can have your hand on both props i.e large Dia and big pitch or small Dia and large pitch do it and test trial your engine for that. It will give us more experience and you a non ripping engine.
And as for whooping I always thought about Indiana Johns whip...