stangflyer
I like 'em "BIG"!
After yesterdays successful maiden of the Sukhoi, I got to thinking about that monster motor and the way it ripped the prop so badly. I talked with Dave, @Planebender this afternoon and it was suggested that perhaps that prop is not the best choice right now. Maybe better for slower 3D but not for the kind of paces I put her through yesterday. Since I have a new Falcon 32x11 I decided maybe I would give it a try and see if I could calm down that rip a bit. Well, as it turns out... I was much-much more successful than first thought. More along the lines of damn lucky. I removed the spinner this evening and I was very dismayed to find carbon fiber filings falling out as I removed the spinner. Now I have heard from many people that it is not a good idea to run a carbon back plate as they have a tendency to loosen and cause some serious damage. I have however been very cautious and payed very close attention to the ones I have run thus far and not even a single issue. The 260 now has 45 flights on it with the exact same spinner as the one I am using on the Sukhoi. It is still like brand new. I've been running the same manufacturer on my smaller motors and not even one issue. So how can it be with just one "8" minute flight I could have this happening?
Upon removing the prop hub bolts, I found they were "ALL" loose. Two of them finger loose. Much more dismay lay ahead. Two bolts sheared side by side. What the heck??? Have the gremlins finally caught up with me? This I do not know and thus the reason I am posting this thread. That and also to filter out to everyone some insight and some knowledge in case they are as in the dark as I am.
First: Carbon Fiber filings from inside the spinner.
Second: Two sheared prop bolts.
Third: Prop damaged on two sides.
Fourth: Back of prop damaged.
Fifth: Inside of spinner back plate damaged.
A couple of things come to mind. First, I am certain I torqued the bolts down. As I used my new torque wrench when I did them. I set them all to 110 in. pounds. Question: Was this enough? Next, Nord locks: I have been using them with super success however when I purchased them for this motor, I could not find 6mm. The ones I purchased were an SAE between 6 and 7 mm. They were not a perfect fit, but I felt they would be fine. Question: Is it possible there was enough play in them to allow this to happen? Since the back of the back plate is not damaged and only the contacting surface of the spinner and the prop are damaged, Could there have been enough heat from the hub that would cause the bolts to loosen? I kind of feel this would not be the case as the back of the back plate is perfectly un-damaged.
Is that motor making so much more power that a carbon fiber back plate just can not be used? My personal opinion is: The culprits are the non perfect fitting Nord Locks. Or is it possible that it is a combination of all factors? That is why I am posing the question to all you out there that have more experience with issues like this.
What did I miss or overlook? I would be very grateful if any of you that know, would jump right in and help me (and others) out with some answers.
And by the way, Is the 3W prop toast? Or is it possible to save it and safely use it later?
Upon removing the prop hub bolts, I found they were "ALL" loose. Two of them finger loose. Much more dismay lay ahead. Two bolts sheared side by side. What the heck??? Have the gremlins finally caught up with me? This I do not know and thus the reason I am posting this thread. That and also to filter out to everyone some insight and some knowledge in case they are as in the dark as I am.
First: Carbon Fiber filings from inside the spinner.
Second: Two sheared prop bolts.
Third: Prop damaged on two sides.
Fourth: Back of prop damaged.
Fifth: Inside of spinner back plate damaged.
A couple of things come to mind. First, I am certain I torqued the bolts down. As I used my new torque wrench when I did them. I set them all to 110 in. pounds. Question: Was this enough? Next, Nord locks: I have been using them with super success however when I purchased them for this motor, I could not find 6mm. The ones I purchased were an SAE between 6 and 7 mm. They were not a perfect fit, but I felt they would be fine. Question: Is it possible there was enough play in them to allow this to happen? Since the back of the back plate is not damaged and only the contacting surface of the spinner and the prop are damaged, Could there have been enough heat from the hub that would cause the bolts to loosen? I kind of feel this would not be the case as the back of the back plate is perfectly un-damaged.
Is that motor making so much more power that a carbon fiber back plate just can not be used? My personal opinion is: The culprits are the non perfect fitting Nord Locks. Or is it possible that it is a combination of all factors? That is why I am posing the question to all you out there that have more experience with issues like this.
What did I miss or overlook? I would be very grateful if any of you that know, would jump right in and help me (and others) out with some answers.
And by the way, Is the 3W prop toast? Or is it possible to save it and safely use it later?