Pulling what's left of my hair out!!! Loose clutch!

[Sgt_BF_Gunner]

Hello All,

Finished my Raptor 50 Titan build a short while ago.

I can't get her off the ground though because the "$%^#&!*ing!" fan/clutch keeps coming loose and running up the motor shaft into the clutch bell seizing it up and stall the engine.

I am running an OS 50 Hyper. I guess I have to be thankful it won't let me take off as I don't want it to come un-done in mid flight.

I have read not to use the washer that comes with the OS engine. Just screw the fan on and crank down the nut with some Locktite.

First time I used blue Locktite, second time I tried red.

I pulled the motor once again to find the nut backing off. I have the right tools and I cranked the fan down and then the nut.

What in the world am I doing wrong?!?!? With what I have experienced, how can this thing do 3-D time after time and keep coming back for more when mine unscrews itself at idle???

Day wasn't totally shot because I just plugged the battery in my T-Rex and off I went, no fuss no muss.

One more question... My Helimax super starter motor runs the engine counter clockwise (oposite of my kid's nitro car). Blades spin and everything is spinning in the correct direction after. You'd think the would reverse the threads on this bad boy.

I think I'm going to need an anger management course! :shock:

Thanks,
Gary

[ferincr]

What in the world am I doing wrong?!?!? With what I have experienced, how can this thing do 3-D time after time and keep coming back for more when mine unscrews itself at idle???
I'm not sure how you doing this, but what you have to crank tight is the "propeller"nut into the fan, you said you have all the right tools, so screw the fan (I didn't use the washer on my R60 either) then hold it in place with the proper tool (either the crankshaft clamp or the home made spatula thing in Raptortechnique) and then really crank the nut into the fan while holding this one. It shouldn't come loose, I haven't even loctited
mine.
One thing to keep in mind is when you are cranking the nut tight make sure the fan does not rotates with it too, you need to create tightness between these two for them to hold in place



One more question... My Helimax super starter motor runs the engine counter clockwise (opposite of my kid's nitro car). Blades spin and everything is spinning in the correct direction after. You'd think the would reverse the threads on this bad boy.
as far as I know all the glow plug engines I ever had, rotate counter clockwise

hope this helps somehow,

[Sgt_BF_Gunner]

Thanks Fernando. I tighten the fan all the way down by hand using the crankshaft clamp. Still makes me nervous thought because even with the crackshaft tool holding things in place it seems like you could snap something in there with too much pressure.

Then I put on the nut and tighten it down with a socket wrench.

Fire up the engine and 10 seconds later, everything is falling apart.

I'm no little guy, and my wife accuses me of giving everything just one more twist, thereby snapping things off.

I even used red loctite...

I'll try again... and again... and again...

Thanks,
Gary

[ferincr]

It sounds weird, but if anything else why don't you make one of those scraper fan holding tool and give it a try. http://www.raptortechnique.com/fanhubtool.htm
That way you are kind of counter rotating the fan and the nut against each other.
That technique always worked for me even using two nuts to get threaded rods out of engine parts.

[BarracudaHockey]

Clean the threads, use acetone and get ALL of the dried locktite off.

Get the fan good and tight, you dont have to break anything.

Use blue locktite on both the fan (screw on type) and nut.

Here's the key. LET IT SIT for 24 hours for the locktite to fully cure.

[Sgt_BF_Gunner]

Gentlemen,

So do I use the washer that came with the motor? The washer fits around the shaft right down to the bearing at the front of the motor. Doesn't seem like it would be useful for tightening the fan up to.

Also, how much torque can I put on this fan with the crankshaft tool holding everything? I seems like if I put some elbow grease into it I would be bending or snapping some internal parts.

I read one post that says running the motor runs in a direction that would keep the threads tight except for starting. Doesn't it all run in the same direction> Why would starting be different from running?

I still can't believe that something so tempermental leads to a heli that cab tear up the sky.

I will try all the above suggestions. Just not sure about the washer or how much torque to put on the crank shaft with the nylon tool at the back end and a 220 pound guy cranking the fan on on the other end.

Thanks,
Gary

[ferincr]

I read one post that says running the motor runs in a direction that would keep the threads tight except for starting. Doesn't it all run in the same direction> Why would starting be different from running?

Well, yes, but if you rotate the shaft with the starter through the one way bearing in the clutch, the compression of the piston would act as resistance in the opposite direction loosing the nut up
While if the engine is running by itself the torque comes from the cranckshaft (not the clutch/nut) so it works the opposite way.

As far as the washer I don't think it has anything to do with tightening things up but it will move the whole setting (fan/clutch) up the same distance as the thickness of the washer, so you have to see how the clutch sits on the bell once the engine is in place and decide if you want that extra 1/32" (or whatever the thickness of the washer is) up or not.

[BarracudaHockey]

No washer, it can/will push the clutch up into the bottom of the clutch bell.