RCU Forums

RCU Forums (https://www.rcuniverse.com/forum/)
-   Beginners (https://www.rcuniverse.com/forum/beginners-85/)
-   -   Spinner question (https://www.rcuniverse.com/forum/beginners-85/7710700-spinner-question.html)

F4U Corsair 07-09-2008 07:29 AM
Spinner question
 
I want to put the smaller alum. or brass spinner nut on to replace the large plastic spinner. They have a hole and what looks to be flats on the back. I'm guessing you can use a wrench on the flats, or anything small enough to go through the hole to tighten the spinner.

My question is:
What is the proper prop position before tightening (or does it matter), and what keeps the starter from loosening the spinner?

Nathan King 07-09-2008 09:42 AM
RE: Spinner question
 
I'm not sure what you are getting at with tightening, but I can help with your question. There is no prop position that keeps the starter from loosening the spinner, however there is a prop position that lessens the chance of breaking a prop on a deadstick and makes it easier to hand prop. When looking at the front of the airplane turn the engine crank counterclockwise until you hit compression. Now tighten your prop so that it sits horizontally.

cappaj1 07-09-2008 09:55 AM
RE: Spinner question
 

ORIGINAL: Nathan King

I'm not sure what you are getting at with tightening, but I can help with your question. There is no prop position that keeps the starter from loosening the spinner, however there is a prop position that lessens the chance of breaking a prop on a deadstick and makes it easier to hand prop. When looking at the front of the airplane turn the engine crank counterclockwise until you hit compression. Now tighten your prop so that it sits horizontally.
Dang, Nathan King, you seem to know something about almost anything. That's a good tip! Problem is with a newb like me, I have no idea of when I hit compression. Would that be when you feel the beginning of resistance, a half turn after, etc. I really don't know.

Also, why would an engine stop at this point if it stopped running? I'm guessing the same reason - resistance at that point.

By the way, how long you been at this?

F4U Corsair 07-09-2008 09:57 AM
RE: Spinner question
 
Nathan, thanks for the prop position, that makes since for dead stick landings.

The question I had about tightening the spinner nut was, what keeps the starter from loosening the spinner nut (starter turns the spinner nut the same direction as removing it with a wrench, seems like the starter would loosen the nut up especially with multiple starts?

Allfat 07-09-2008 10:16 AM
RE: Spinner question
 
What keeps the spinner nut on is you putting it on really tight.

I used one on my trainer and the starter would take it off sometimes, but it usually stayed on. And if it does come off, all you have to do it thread it on, tighten it down, and try again.

And you are right with using a crescent wrench or a small screwdriver to tighten it down. Either will work fine.

F4U Corsair 07-09-2008 10:41 AM
RE: Spinner question
 
Thanks, I was looking for a set screw or something to lock in on. Am I correct that the spinner nut replaces the small 1/4x28 nut that comes with the engine (you don't use both correct)?

Allfat 07-09-2008 10:47 AM
RE: Spinner question
 
Yes, it replaces the prop nut. And I did not use any sort of set screw or lock nut or anything like that and I never had a problem.

brett65 07-09-2008 10:53 AM
RE: Spinner question
 
A guy at my field uses spinner nuts, and he just puts the rubber end of the starter over it and against the prop. If tuned correctly, it should start with just a quick bump like mine does.

Nathan King 07-09-2008 10:59 AM
RE: Spinner question
 
ORIGINAL: cappaj1


ORIGINAL: Nathan King

I'm not sure what you are getting at with tightening, but I can help with your question. There is no prop position that keeps the starter from loosening the spinner, however there is a prop position that lessens the chance of breaking a prop on a deadstick and makes it easier to hand prop. When looking at the front of the airplane turn the engine crank counterclockwise until you hit compression. Now tighten your prop so that it sits horizontally.
Dang, Nathan King, you seem to know something about almost anything. That's a good tip! Problem is with a newb like me, I have no idea of when I hit compression. Would that be when you feel the beginning of resistance, a half turn after, etc. I really don't know.

Also, why would an engine stop at this point if it stopped running? I'm guessing the same reason - resistance at that point.

By the way, how long you been at this?
You hit compression when the engine gets difficult to turn over (beginning of resistance). It becomes difficult to turn over because the piston has closed all intake/exhaust ports on the sleeve and is beginning to "compress" the fuel/air mixture. If you seal a space and reduce the volume, the contents must compress. The engine stops at this point because it hits the resistance and doesn't have enough momentum to continue through without combustion from the previous cycle. It's also good to position the prop there just in case you need to hand start the engine. To start it, you must flip through compression into combustion, so the prop is in an ideal place to really get a good swing on it.

I'm just a regular joe like you; I put my pants on one leg at a time. I fly full scale and read every bit of information I can get my paws on, so that always helps. I'm actually not very old, although most people here assume I am for some reason.

Happy flying!
Nathan King

cappaj1 07-09-2008 01:43 PM
RE: Spinner question
 

ORIGINAL: Nathan King

ORIGINAL: cappaj1


ORIGINAL: Nathan King

I'm not sure what you are getting at with tightening, but I can help with your question. There is no prop position that keeps the starter from loosening the spinner, however there is a prop position that lessens the chance of breaking a prop on a deadstick and makes it easier to hand prop. When looking at the front of the airplane turn the engine crank counterclockwise until you hit compression. Now tighten your prop so that it sits horizontally.
Dang, Nathan King, you seem to know something about almost anything. That's a good tip! Problem is with a newb like me, I have no idea of when I hit compression. Would that be when you feel the beginning of resistance, a half turn after, etc. I really don't know.

Also, why would an engine stop at this point if it stopped running? I'm guessing the same reason - resistance at that point.

By the way, how long you been at this?
You hit compression when the engine gets difficult to turn over (beginning of resistance). It becomes difficult to turn over because the piston has closed all intake/exhaust ports on the sleeve and is beginning to "compress" the fuel/air mixture. If you seal a space and reduce the volume, the contents must compress. The engine stops at this point because it hits the resistance and doesn't have enough momentum to continue through without combustion from the previous cycle. It's also good to position the prop there just in case you need to hand start the engine. To start it, you must flip through compression into combustion, so the prop is in an ideal place to really get a good swing on it.

I'm just a regular joe like you; I put my pants on one leg at a time. I fly full scale and read every bit of information I can get my paws on, so that always helps. I'm actually not very old, although most people here assume I am for some reason.

Happy flying!
Nathan King
Thanks, Nathan.

Why would the engine stop at this point though, because of the resistance from the compression stroke?

Also, what is that model you have for your Avatar. For some reason GeeBee or something like that rings a bell.

Allfat 07-09-2008 01:57 PM
RE: Spinner question
 
It would not necessarily stop at that point when it dies, but it will find its rest againt compression. When the engine dies, there is no more power to the propellor, but the airplane is still moving. As the air passes over the unpowered prop, then it will rotate it in a counterclockwise direction as long as there is little resistance to rotation. As soon as it hits resistance (compression) then it stops the rotation and stays there.

brett65 07-09-2008 02:11 PM
RE: Spinner question
 
Its a GeeBee racer.

Nathan King 07-09-2008 02:40 PM
RE: Spinner question
 
More specifically, it's a model of the GeeBee R-2 Racer. The R-1 and R-2 were built for the 1932 races. The main difference between the two was the engines. The R-1 had a Pratt and Whitney WASP engine for the Thompson Trophy Race. The R-2 had a Pratt and Whitney WASP Jr. R985. This aircraft was built for the Bendix Trophy Race, which was an endurance race.

On December 23, 1991 Delmar Benjamin test flew his R-2 replica. He essentially pulverized the myth that the GeeBee was a deathtrap.


All times are GMT -8. The time now is 07:37 PM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.