RE: Dualsky 6360-12T props  
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RE: Dualsky 6360-12T props - 12/3/2007 9:10:30 PM   
shannah


 

Posts: 205
Joined: 9/6/2004
From: placentia, CA, USA
Status: offline 		What prop adapter part number are you guys using with tru-turn spinners?

(in reply to patternflyer1)
       Post #: 26

RE: Dualsky 6360-12T props - 12/3/2007 10:14:21 PM   
LCHelilover


 

Posts: 130
Joined: 5/17/2003
From: Lake Charles, LA, USA
Status: offline 		I just call Tru turn and tell them what I need- they are very helpful and knowledgeable.

George

(in reply to shannah)
       Post #: 27

RE: Dualsky 6360-12T props - 12/15/2007 7:52:40 AM   
shannah


 

Posts: 205
Joined: 9/6/2004
From: placentia, CA, USA
Status: offline 		Well,

I really liked the 22x12. That is until the motor blew apart in flight. I had just throttled up at the bottom of the two loops with full roll when there was an instantaneous BANG. I thought I blew off a horizontal stab since that is what it sounded like. I saw the chin cowl fly off and some shiny pieces scattering through the air. There was no vibration sound, no rattling, no nothing. Just a loud BANG.

The motor was gone. The nose ring had been ripped out. I never found the motor. I found the prop/spinner/prop hub. The prop shaft was still in the prop hub but it was sheared off at the pin that goes through the shaft. I think the motor may have siezed and blown apart. There was a very odd hole punched in the top of the nose in addition to the other damage. Whatever happened, it was quick and violent. No shaking or vibrating.

I don't think this was the infamous bass-o-matic failure mode.

Anyway, its a real shame since I loved the performance on the 22x12. fantastic. Now I have quite a repair job ahead of me. Anyone know someone good at glass work in SoCal? I will put a firewall in and mount my next outrunner to the firewall. Just don't think it will be Dualsky. What a shame because it had great performance on the 22x12.

Steve.

(in reply to LCHelilover)
       Post #: 28

RE: Dualsky 6360-12T props - 12/15/2007 10:40:52 AM   
serious power


 

Posts: 69
Joined: 11/19/2007
From: wexford, IRELAND
Status: offline 		Bad luck. What is 'bass o matic' failure??

< Message edited by serious power -- 12/18/2007 12:19:31 PM >

(in reply to shannah)
       Post #: 29

RE: Dualsky 6360-12T props - 12/15/2007 3:08:31 PM   
Dean Pappas


 

Posts: 164
Joined: 1/27/2004
From: South Plainfield, NJ, USA
Status: offline 		Bass-O-Matic = Whirl-Whip Flutter ... and it could be.
Who says that whirl-whip will continue for more than 1 cycle or two before tearing the nose out? I witnessed this on the ground, once.
It didn't go Br-Br-Br-Br-BRUP!. ..... It went BRAP! in one shot. Yes, maybe 10 or 20 revolutions were involved but that's a 1/10 or 1/4 of a second!
You would hear a single shotgun-like report, at a distance. Does the hole in the top of the fuse have smiley shape?

later and I hope you get it fixed,
Dean Pappas

(in reply to serious power)
       Post #: 30

RE: Dualsky 6360-12T props - 12/15/2007 3:44:41 PM   
serious power


 

Posts: 69
Joined: 11/19/2007
From: wexford, IRELAND
Status: offline 		We had this, but sometimes a prolonged buzz/chatter.It was due to the connectors we were using. Whats the normal cause ??


Brian C,,

(in reply to Dean Pappas)
       Post #: 31

RE: Dualsky 6360-12T props - 12/15/2007 4:56:25 PM   
OhD


 

Posts: 413
Joined: 10/23/2002
From: west hills, CA, USA
Status: offline
quote:

ORIGINAL: shannah

Well,

I really liked the 22x12. That is until the motor blew apart in flight. I had just throttled up at the bottom of the two loops with full roll when there was an instantaneous BANG. I thought I blew off a horizontal stab since that is what it sounded like. I saw the chin cowl fly off and some shiny pieces scattering through the air. There was no vibration sound, no rattling, no nothing. Just a loud BANG.

The motor was gone. The nose ring had been ripped out. I never found the motor. I found the prop/spinner/prop hub. The prop shaft was still in the prop hub but it was sheared off at the pin that goes through the shaft. I think the motor may have siezed and blown apart. There was a very odd hole punched in the top of the nose in addition to the other damage. Whatever happened, it was quick and violent. No shaking or vibrating.

I don't think this was the infamous bass-o-matic failure mode.

Anyway, its a real shame since I loved the performance on the 22x12. fantastic. Now I have quite a repair job ahead of me. Anyone know someone good at glass work in SoCal? I will put a firewall in and mount my next outrunner to the firewall. Just don't think it will be Dualsky. What a shame because it had great performance on the 22x12.

Steve.


Steve,

Did you have a retaining bearing or bushing on the back of the motor, the rotating bell end? I've got 150 flights on mine, most with the 22x12 and it is very consistent with no problems. For your info I loaned my 6360 11T to a friend who mounted it the other way, on a box on the firewall and it seems to run very nice. Only two flights so far but it sounds great.

Jim O






(in reply to shannah)
       Post #: 32

RE: Dualsky 6360-12T props - 12/15/2007 5:52:53 PM   
shannah


 

Posts: 205
Joined: 9/6/2004
From: placentia, CA, USA
Status: offline 		The only bushing I remember seeing was the brass colored collar that was on the prop shaft. I don't remember seeing anything on the back side of the motor. It was a front nose mount and was bolted into the location of the old Axi it was replacing.

I'm not sure what would have caused this. My underdstanding is that the bass o matic failure would be caused by some structural weakness of the front end that gives way under a harmonic vibration etc. I don't think this is the case since a fairly small area is gone. But, I haven't witnessed one before.

I also find it odd that I have what looks like a shrapnel exit wound on the top of the fuse.

(in reply to OhD)
       Post #: 33

RE: Dualsky 6360-12T props - 12/15/2007 7:15:39 PM   
shannah


 

Posts: 205
Joined: 9/6/2004
From: placentia, CA, USA
Status: offline 		Here are a couple pics. It is what it is. It is definitely repairable, but I am going to put in a firewall mount because I don't think I'll be able to get the nose mount integrity back. Looks like this is a mystery. Likely culprits: 1) Nose ring mount let go, motor twisted itself loose and prop hit fuse which sheared off shaft (not sure about the exit wound) , 2)prop shaft sheared off in flight, motor was at full throttle and over rev'd and seized up. the torque ripped it out of the plane (still no answer for exit wound). 3)motor seized up suddenly (not sure how, magnet came loose?) the sudden stop was absorbed by the prop shaft shearing off, the motor mount ripped out as the motor came apart (maybe a piece exited the fuse). 4)someone was hiding in the weeds and shot it, the bullet went through the top of the fuse (I was inverted) and blew the motor out of the fuse.

I won't know for sure since I found no remains of the motor. It either launched into the high brush or spread itself out over a wider area. I still have a plane so I'm pretty lucky.

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(in reply to shannah)
       Post #: 34

RE: Dualsky 6360-12T props - 12/15/2007 9:44:58 PM   
ual767



Posts: 752
Joined: 12/3/2002
From: Chantilly, VA, USA
Status: online 		You cannot mount a big outrunner to the nose of a composite plane and have it last very long. Might last a while but it will fail unless the rear of the motor is also supported. There are too many reports of just what you describe happening to those that tried to nose mount a big outrunner. I had a total of 2 flights on my Genesis before it failed the first time. I repaired it and mounted it that way again and got another 20 or so flights before it failed again. Repaired it again but added a back support for the rear of the motor and it worked perfectly for quite a while before it crashed for an unrelated reason.

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(in reply to shannah)
       Post #: 35

RE: Dualsky 6360-12T props - 12/15/2007 10:11:03 PM   
OhD


 

Posts: 413
Joined: 10/23/2002
From: west hills, CA, USA
Status: offline
quote:

ORIGINAL: shannah

Here are a couple pics. It is what it is. It is definitely repairable, but I am going to put in a firewall mount because I don't think I'll be able to get the nose mount integrity back. Looks like this is a mystery. Likely culprits: 1) Nose ring mount let go, motor twisted itself loose and prop hit fuse which sheared off shaft (not sure about the exit wound) , 2)prop shaft sheared off in flight, motor was at full throttle and over rev'd and seized up. the torque ripped it out of the plane (still no answer for exit wound). 3)motor seized up suddenly (not sure how, magnet came loose?) the sudden stop was absorbed by the prop shaft shearing off, the motor mount ripped out as the motor came apart (maybe a piece exited the fuse). 4)someone was hiding in the weeds and shot it, the bullet went through the top of the fuse (I was inverted) and blew the motor out of the fuse.

I won't know for sure since I found no remains of the motor. It either launched into the high brush or spread itself out over a wider area. I still have a plane so I'm pretty lucky.



I'm sorry for your loss but I must admit I started laughing out loud thinking about scenario number 4.

I agree with Chris, you need to support the back end when mounting on the nose ring. Jerry B had a broken shaft like yours. I'm surprised he didn't jump in here to describe his situation.

Jim

(in reply to shannah)
       Post #: 36

RE: Dualsky 6360-12T props - 12/15/2007 10:32:30 PM   
patternrules


 

Posts: 547
Joined: 7/28/2002
From: Nineveh, IN, USA
Status: online 		I'm thinking #1 seniro is what happened or I would bet on it any way, I'm like Chris had the nose break loose and I even had a rear support with a bearing. One thing that comes into play is the "glass" work of the manufacture, if there is any flaw noticeable or not which was the case with mine. I just firewall mount now and have no problems at all.
A little note there have been some top flyers that have used the nose mount with many flights that have finally had issues with the nose mount but caught in time to fix before a failure.
Steve Maxwell

_____________________________

Steve Maxwell

(in reply to OhD)
       Post #: 37

RE: Dualsky 6360-12T props - 12/15/2007 10:45:04 PM   
shannah


 

Posts: 205
Joined: 9/6/2004
From: placentia, CA, USA
Status: offline 		I think I should start a new thread on the topic of outrunner mounting. I am not sure how to add a rear support. This is new to me. I think I'll chalk this up to nose ring failure.

So, I am going to make a firewall mount. Do you have to come up with a front support for the motor?

(in reply to patternrules)
       Post #: 38

RE: Dualsky 6360-12T props - 12/15/2007 10:54:50 PM   
ual767



Posts: 752
Joined: 12/3/2002
From: Chantilly, VA, USA
Status: online 		Here are 2 pics. Zeque with Axi F3A motor on a firewall mount (no nose support needed. And Genesis with Hacker A60 nose mounted with back support added.

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