kyled921
Rocketeer
- Joined
- Jul 20, 2015
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Figured I'd get some feedback and possible discussion of the CATO I experienced over the weekend. It was a CTI 54mm 2 grain J145-SK in a 3G casing w/ spacer. Simple motor ejection in my HyperLOC 835. 3,2,1...Poof! Attached is a photo with many pieces airborne. In my haste to recover said rocket from the pad and bring it to our local vendor for diagnosis, I did not locate the second eye bolt (first is embedded in the spacer) nor the forward closure assembly. I filed a MESS report and believe motor date was from Oct. 2015, although I had bought this on the day of the launch.
Extent of damage:
All in all, salvagable. Will need to cut just below old coupler and fit new body tube, coupler, CR, and eyebolts. Will need another Aeropack (have a spare for phenolic) and will reattached with JB weld. Will need new JL Alt 2, only had 5 flights on it . Repaint and add new vinyl.
Any ideas on what might have caused this? I had adjusted the delay using the tool, but hadn't gone too short (maybe -7s). For some reason I am thinking there is a BP charge at the top of the motor propellant grains to help with ignition. Maybe that cause over-pressure event? The damage suggests a significant amount of energy (open the motor casing with the spacer AND embed it into three pieces of steel), and the motor ejecting from the bottom would support an over-pressure event between the delay and the propellant grain. What are your thoughts TRF?
Extent of damage:
- Nose cone/e-bay all good. Just some scuffs.
- Recovery harness centering ring completely shredded. This had two eyebolts and was secured below a coupler joining the upper and lower body tubes.
- Upper body tube shredded just above coupler. Seems like an explosive separation as there is a clean break line at the top end of the coupler.
- Motor casing forward end where the tubing is bent was straightened out from the spacer/forward closure launching skyward. Phenolic liner partially stuck. Propellant grain intact and unburnt.
- Aeropack retainer completely stuck to casing. Sheared right off cardboard motor tube. Stayed with casing/vendor.
- Spacer completely embedded into the steel eybolt and bent the 1/4" quick link. Needed to pry aluminum apart to get recovery harness out.
- Jolly Logic Alt 2 LCD fractured. Would not turn on. Body case cracked. Looks like a gonner.
- JL Chute release survived!
All in all, salvagable. Will need to cut just below old coupler and fit new body tube, coupler, CR, and eyebolts. Will need another Aeropack (have a spare for phenolic) and will reattached with JB weld. Will need new JL Alt 2, only had 5 flights on it . Repaint and add new vinyl.
Any ideas on what might have caused this? I had adjusted the delay using the tool, but hadn't gone too short (maybe -7s). For some reason I am thinking there is a BP charge at the top of the motor propellant grains to help with ignition. Maybe that cause over-pressure event? The damage suggests a significant amount of energy (open the motor casing with the spacer AND embed it into three pieces of steel), and the motor ejecting from the bottom would support an over-pressure event between the delay and the propellant grain. What are your thoughts TRF?