Extreme Speed Prop Planes Discuss the need for speed with fast prop planes (Screamin Demon, Diamond Dust, Shrikes or any REAL sound breakin'''' plane)

max spinner rpm

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Old 07-27-2009, 08:31 PM
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planeguy52
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Default max spinner rpm


Hi guys, I am mounting a Jett 60lx on a Balsa USA Northstar and would like to run a 2 1/4 inch plastic Dubro spinner to match the cowl. Jett claims up tp 18k rpm. I need info on safe rpm for spinners. Thanks. DB
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Old 07-27-2009, 09:13 PM
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Default RE: max spinner rpm

Have you ever juggled live grenades?
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Old 07-27-2009, 09:47 PM
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Default RE: max spinner rpm

Wonder how fast the machine turns that forms the spun aluminum spinners.
2" Plastic Dubro is good for 18,000, I can tell you that. Used them on a OS .32 for many years.
I'll guess 2" spun aluminum is good for a zillion [10 to the 100th power] rpm.
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Old 07-28-2009, 06:30 AM
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Default RE: max spinner rpm

I don't think the issue is the rpm but what will hold up to the starter motor and the first kickback......
Go aluminium with that motor.
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Old 07-28-2009, 02:09 PM
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Default RE: max spinner rpm

if any of you remember CB spinners and engine mounts they stated that plastic was ok to about 13-14 k rpm before distortion caused imbalance and the risk of exploding, mind you they had aluminum backplates....MPI and others such as Spinrite have spinners in the 12-13 dollar range, that are very strong,a bit cheaper than my tru-turns but hey they run pretty well with almost nil balancing
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Old 07-28-2009, 02:42 PM
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Ed Smith
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Default RE: max spinner rpm

planegut52,

If you have ever had a plastic spinner explode in your face while using a starter you will not use a plastic one again. Ever.

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Old 07-28-2009, 03:22 PM
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Default RE: max spinner rpm

You can get a COLORED metal spinner form Tru Turn.
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Old 07-28-2009, 09:53 PM
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Default RE: max spinner rpm


ORIGINAL: planeguy52


Hi guys, I am mounting a Jett 60lx on a Balsa USA Northstar and would like to run a 2 1/4 inch plastic Dubro spinner to match the cowl. Jett claims up tp 18k rpm. I need info on safe rpm for spinners. Thanks. DB
NO plastic spinner !!! The 60LX will eat it for lunch, and the are difficult to balance.

Colored Tru-Turn is the best option.
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Old 07-28-2009, 10:26 PM
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Default RE: max spinner rpm

if any of you remember CB spinners
I ran the CB metal spinners on some early Formula One engines. They were unbalanced crap too due to the fact that they were cast cones. Because of the dynamics of rotating bodies, balancing a spinner is practically impossible to do with the tools available to the average hobbiest.

The CB spinner put too much strain on the bolt holding the cone to the adapter because of it inherent unbalance, and eventually it would snap and another spinner cone would depart the airplane. Examination of the remain piece of bolt showed that it work harden, developed a crack and fail. After loosing a couple I found that the only way I could avoid this was to change out the bolt after every 10 flights.

However Tru-Turn spinners run with very little stress on the bolt. I once started a racing engine with the center screw loose, and the Tru-Turn cone stayed completely in the backplate groove and ran without any pressure from the screw to hold the cone in place.

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Old 07-28-2009, 10:43 PM
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planeguy52
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Default RE: max spinner rpm

Thanks for the info guys, Tru turn it is.
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