The spinning spinner

[Sired by Fire]

i have a Tru Turn 4" ultimate style spinner mounted on a piped da 85 that i cant keep from slipping on the back plate and hitting the prop. i have torqued the snot out of it, and well it slipped and cracked. have a replacement on the way and i dont want to dust another one. so how do you guys keep em from sliding on the back plate with out screwing with the balance?

[JoeAirPort]

The short end of an allen wrench using your index finger and thumb is all the torque you'd want to put on it. Usually the prop moves on a one bolt setup hitting the spinner. Never had a problem with the spinner moving on the back plate. Maybe it's too tight? Is it back firing?

[Lowkey3D]

Maybe the Spinner bolt is too long and bottoming out and not tighten down the spinner.

[JoeAirPort]

haha, that could actually be the problem. Good idea.

[gareth.ky]

Hmm this sounds familiar. I had a Tru Turn 4 1/2" spinner that was "walking" on the back plate. At some point it cracked and people suggested I had over tightened it. Then on Sunday "something" happened and the spinner turned into a flail and the whole motor ripped off the motor box.

Either the crack became fatal or the bolt come loose enough to let the spinner slip free of the backplate. See this.

I talked with a few experienced people and they agree that you tighten the bolt between 1/4 and 3/8 of a turn past the point where it makes contact.

The bolt is not bottoming out.

[Sired by Fire]

prop is not slipping, and the motor runs like a top. the spinner bolt is also the correct length. Been doing some searching and found Khedge had a similar problem with a TBM spinner and he used a lock washer on the spinner bolt to remedy the slip, im going to give that a try and report back. thank you for the suggestions.

[Sired by Fire]

	Quote: Originally Posted by gareth.ky
	Either the crack became fatal or the bolt come loose enough to let the spinner slip free of the backplate. See this.

Holy Sheet mang thats carnage
i have been tighten the bolt to TT specs, just wasnt cutting the mustard... so i would give it a little more and it would still slip.... then a little more and then finally with the compression from the bolt and rubbing on the prop it cracked out. but after seeing those pics Gareth im glad i never ran it cracked and avoided disaster

[stommerd27]

I wouldn't rule out the bolt bottoming out. My Tru Turn the bolt bottomed out. But it was quite loose still. I cut about 1/2" off of the bolt and it has never come loose.

Shane

[Sired by Fire]

no really its been ruled out

[aviti]

I've had probably 10 different Tru-Turn spinners on 2 stroke glow, 4 stroke glow, 100 cc gas. I have never had one even be the slightest bit loose when I go to remove the spinner.

I suspect yourcenter bolt is bottoming out. How did you check to make sure it is not?

[gareth.ky]

The hole in the shaft is a good 4cm deep and the threads on the spinner bolt are maybe 3cm long. About 1.5cm of the threads on the bolt are in the shaft. I just went to the garage and checked with a ruler, another bolt and a ball driver shaft as a probe.

To make it stop slipping we made it too tight and it cracked.

So maybe there is some way to add some friction to where the back plate and the spinner meet to stop the slipping?

[gareth.ky]

So, this may be nothing it may be something. Around the lip on the backplate I have this black dust. I'm guessing this is aluminum rubbed off due to vibration.

[Vic3D]

	Quote: Originally Posted by gareth.ky
	So, this may be nothing it may be something. Around the lip on the backplate I have this black dust. I'm guessing this is aluminum rubbed off due to vibration. Attachment 132647

I could show you another place where there would be black stuff if that happened to me while flying!!

[inicol]

Try putting some silicon on the edge of the spinner cone before bolting on

[gareth.ky]

	Quote: Originally Posted by Vic3D
	I could show you another place where there would be black stuff if that happened to me while flying!!