fyrfytr310
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- Jul 6, 2006
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I use a jam nut and loctite. I have no reference on the use of a split washer, I'll leave that for others who have used them. Makes me nervous, but it might work ok.
Does anyone have vibration analysis data from HPR motors (I don't see the recovery stage being an issue)? Seems like most vibration would be in the axial direction as opposed to the lateral or torsional directions shown in the test. Also, the test appears to have the threaded rod fixed which would not be the case in a rocket recovery system scenario. I would think that the eye bolt would vibrate at the same frequency and in the same direction as the motor case yielding no relative motion between the components and no loss in the integrity of the joint. This said, the motor is not the only source of vibration, there would also be aerodynamic and sonic sources but again, we aren't talking NASA level sustained flight (the only sources I could find on this topic). This is all adding up to some desire to develop my own vibration detection system for further study. :cool2:
Not arguing here with anyone, just wanting to expand my knowledge and apply accordingly. Has anyone had a failure at this point in their systems that they can reasonably attribute to the vibrations that occur from motor thrust and non-powered flight? The hillbilly in me says to throw some loctite on it and be done but the engineer in me screams to analyze and understand
Does anyone have vibration analysis data from HPR motors (I don't see the recovery stage being an issue)?
The recovery phase is the issue. The off axial load of the chute opening could loosen it just enough, then the spinning will finish it off. Regardless, I do what successful people do. I don't think a TAP member would approve of a split washer in that application unless loctite was also applied.
Just trying to make sure you have a successful cert flight.
Lol. You guys crack me up. I've seen some builds using clay that turned out well but I think for this one I will stick with what I know.
OK, sure, as CJ also knows, it can work. But much thicker and tougher to get the perfect concave shape. Also tends to be more brittle and prone to cracking. Go for the West, Aeropoxy, US Composites with appropriate fillers or if you do prefer a thicker putty consistency try RocketPoxy (that is as close to clay as I will go).
Not much progress. Took advantage of some downtime at the in-law's to mark the fins for some sanding this week.
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Going to do rounded leading edge with tapered trailing edge. Will leave tips square.
Still need to make the epoxy decision so I can actually put things together. Leaning towards Aeropoxy but I can buy West locally. Part of me wants to try clay for the fillets too but I have never worked with it before so maybe not.
Move the ring down. I sometimes give a bit extra length on the MMT.
That was my plan ultimately but I just wanted to make sure I didn't already screw this thing up. Thanks!
Move the ring down. I sometimes give a bit extra length on the MMT. Also, don't reference anything off of the slots in the shoulder of the cone. Those are oversized slots to make sure there is enough clearance during assembly.
That was my plan ultimately but I just wanted to make sure I didn't already screw this thing up. Thanks!
Forward CR set with West, milled fiber and silica. Resting for the evening. (I hope the fillet on the bottom side doesn't decide to run! I will probably be up checking on it for a while.)
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