Prop Position
#1
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Prop Position
Which is the best way to install the prop on the crank to aid balance? Inline with the rod @ TDC or 90 degrees to it. I have known this in the past but have forgotten which way is proper. I am sure this has been asked a zillion times.
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RE: Prop Position
I use an electric start as this is an older mag engine that is hard if not impossible to hand start. Since prop position for starting is not critical, I would like to place it for best engine balance. I think I remember that the prop lines up with the rod @ TDC, but I am not sure.
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RE: Prop Position
ORIGINAL: planepounder
I use an electric start as this is an older mag engine that is hard if not impossible to hand start. Since prop position for starting is not critical, I would like to place it for best engine balance. I think I remember that the prop lines up with the rod @ TDC, but I am not sure.
I use an electric start as this is an older mag engine that is hard if not impossible to hand start. Since prop position for starting is not critical, I would like to place it for best engine balance. I think I remember that the prop lines up with the rod @ TDC, but I am not sure.
I would make every effort to get your engine properly tuned, cooled, and balance those props/spinners...and fly.
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RE: Prop Position
ORIGINAL: w8ye
I put them so they are horizontal against compression when the engine stops to protect the prop from damage
I put them so they are horizontal against compression when the engine stops to protect the prop from damage
Jack
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RE: Prop Position
Yeah you are probably right about the necessity to do this. I just remembered reading about the influence of prop position relative to the dynamic balance of the rotating mass.The prop is the last balancing element. I am sure each engine would be somewhat different, but there was a rule of thumb to follow on positioning it if a starting position was not required. It is on a great running old Homey 30cc. Just balanced a new prop, and was toying with the position issue, I have tried it both ways and it seems a little smoother at 90 degrees. no big thing, just curious.
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RE: Prop Position
ORIGINAL: planepounder
I use an electric start as this is an older mag engine that is hard if not impossible to hand start. Since prop position for starting is not critical, I would like to place it for best engine balance. I think I remember that the prop lines up with the rod @ TDC, but I am not sure.
I use an electric start as this is an older mag engine that is hard if not impossible to hand start. Since prop position for starting is not critical, I would like to place it for best engine balance. I think I remember that the prop lines up with the rod @ TDC, but I am not sure.
With a three blade prop, the effect is quite a bit less pronounced, so much even as to not to bother.
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RE: Prop Position
Not true. The prop (balanced) still has influence on the mass-motion system. Also, precession forces in a two blade prop tend to oscillate, and prop position relative to the engine can dampen or increase these oscillations.
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RE: Prop Position
ORIGINAL: lewdfinger
I put mine on the front. Never had a problem.
I put mine on the front. Never had a problem.
Hows Obama working out for you?
#15
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RE: Prop Position
I personally like a little wity funny stuff from time to time. Keeps it interesting and for Pete's sake it's a hobby so I don't take everything so seriously. Also, being from Canada he probably didn't get to vote for Obama.
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RE: Prop Position
ORIGINAL: w8ye
So the bottom line is that the position for minimum vibration must be found by trial and error?
So the bottom line is that the position for minimum vibration must be found by trial and error?
For some engines, conversions I believe, the proper position has been posted here on RCU, but I could not find it any more.
I would not bet on it that all engines find benefit in prop indexing. That would be some project to find out.
#20
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RE: Prop Position
ORIGINAL: Ralphbf
And you must of never heard of ACORN.
ORIGINAL: Jezmo
Also, being from Canada he probably didn't get to vote for Obama.
Also, being from Canada he probably didn't get to vote for Obama.
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RE: Prop Position
Whoa!Hold on fellas...
planepounder - sorry if I sounded flippant about your topic. Vibration affects us all. I do believe I asked a very similar question some years ago on this very forum - that's why I was interested to read your post. Dumb thing for me to say - I must have had a few that night.
Ralph - I'd say something witty here but I don't want to start an international incident. Sheesh - take it easy man.
Jezmo - Actually I did get to vote for Obama, Several times, while we were vacationing in Florida. Weird eh?
(Dan Quayle for Prez)
planepounder - sorry if I sounded flippant about your topic. Vibration affects us all. I do believe I asked a very similar question some years ago on this very forum - that's why I was interested to read your post. Dumb thing for me to say - I must have had a few that night.
Ralph - I'd say something witty here but I don't want to start an international incident. Sheesh - take it easy man.
Jezmo - Actually I did get to vote for Obama, Several times, while we were vacationing in Florida. Weird eh?
ORIGINAL: Ralphbf
And you must of never heard of ACORN.
ORIGINAL: Jezmo
Also, being from Canada he probably didn't get to vote for Obama.
Also, being from Canada he probably didn't get to vote for Obama.
#23
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RE: Prop Position
Hey, no offense taken, thought it was pretty funny! Guess I can learn about this concept in my leisure now as I lost the old Telemaster in the sun on final Sunday. Guess what the first thing to the crash site was-yep the old Homey! Talk about vibration now! lol.