Clutchbell slipped down and melted fan shroud.

[Bill Blair]

Hi Guys

I got about 12 flights on the N5c and its really starting to come a live.  I had an issue this past weekend.  I heard a strange sound and landed to find the clutch bell assembly had slipped down and was rubbing the fan shroud.  Luckily nothing else got hurt and the shroud isn't melted to bad.  I wonder what happened to cause that.  It appears its going to be a huge deal to take out.  Does any one have a good method of getting it out besides taking it completely apart?

I would also love to get my hands on that TT conversion   Remember we traded apple pie for it

Thanks
Bill

[flyalan]

Bill,


More than likely the hex adapter has slipped and allowed the bell to drop some.  That can be corrected while still on the heli.  Just loosen the set screw and push the bell up and down on the adapter. Then retighten the set screw.  I suggest you re-locktite the set screw.


The other cause could be the pinion has become unscrewed from the bell.  That will require pulling the clutch stack.  This is highly unlikely though.  It could be possible if your engine had started backwards?


Cheers
Alan

[KevinM]

I would almost say to take it out just to check the entire stack. As Alan said if the clutch stack slid down from the coupler slipping the bearings on the pinion may have suffered...this is just a thought however. I know it may seem like alot of work but you'll be glad you did!   Also with the bearings on the pinion use green loctite spreading a VERY VERY thin layer on the smooth shaft portion of the pinion to hold the bearings in place. it acts as a mild bond between the inner race of the bearings and the smooth shaft portion of the pinion.  It also keeps the inner race from slipping too. Good luck!!

[Kevin Feil]

Bill,

 I agree with both Alan and Kevin, I have seen this numerous times regarding the Hex adapter and Grub screw. There is a flat spot which allows you to adjust the start shaft up and down (very small increment). as long as the shaft is set right within the clutch stack there really shouldn't be any issue. however there is a thread Matt started in the tips and tricks section regarding clutch stack alignment. also you need to make sure the 4 screws (2 on each side ) that hold the clutch stack bearing block are snug and vertically aligned with keeping in mind Gear Mesh. I have seen guys have this canted to one side resulting in a uneven clutch bell to clutch. you should be able to spin the main gear and watch the clutch bell spin with no binding. as the break in they will begin to spin even more freely.. you can also manipulate the fan shroud to obtain the proper clearance between it and the cooling fan itself.. any questions feel free to call me (404) 809-1622. good luck... (To add to what Kevin said "Pull the Assembly out to inspect. if you end up with a improper alignment normally the first thing to go is the bearing surface that fits into the (ONEWAY Bearing) it will snap!!!

Best Regards,

Kevin

[Bill Blair]

OK that was just a test to see if you guys were listing

It was the hex adapter it slipped again....  This time it did let that fall down.

If I order the replacement does it come with the screw?  That's stripped now

Thanks
Bill

[Kevin Feil]

YES, If you end up needing one You call me and I will send you one out of my personal stash 

Best,

Kevin F