Rocketman Dr. Hero

Rocketman Dr. Hero

Contributed by Lew Garrow

Rocketman - D.R. Hero
(Contributed - by Lew Garrow )

Height=108"
Width=3"
Weight=90 ounces

Brief
Modified for CPR (Close Proximity Recovery) and Hybrid Motor.

Hybrid Motor

Modifications
First modification was for Hybrid (Aerotech 54mm hybrid) motor. I discarded the original motor mount and replaced it with a 36" motor mount tube. I then added a PML CPR2000 retrofit kit using the original payload section (18") as the lower recovery section to house the drogue chute. For the main chute I added a 36" section which also lengthened the rocket pushing the CG forward enough to offset the additional motor weight caused by switching to hybrid power.

Hybrid Motor

Rocket PicConstruction
The stock kit was of good quality although the instructions were the standard instructions that come with all the Rocketman kits, that is non-specific to the actual kit. With any prior experience the instructions are adequate. The CPR2000 retrofit kit was very good with detailed step by step instructions. My only doubts about the retro fit kit is the screw together coupling. The plastic chips very easily if you don't firmly hold the halves together as you screw the top and bottom together.

Flight
The rocket got its maiden voyage as my level II cert flight using the Aerotech hybrid with all four apertures open. I replaced the stock elastic with tubular bungi cord.

I flew the rocket on July 11th at the METRA launch in New Jersey. The takeoff was super - and almost smokeless (typical of hybrids). The rocket hit approximately 5400' and separated nicely at apogee. Unfortunately the main chute never came out and the rocket was trashed!

The flight was beautiful - straight as an arrow - the 4.5 second burn made it look like it would climb forever. Inspection afterwards showed that the plastic mounting piece at one end of the altimeter apparently failed when the ejection charge went off. The charge 'blew back' into the altimeter compartment trashing the altimeter, thus the main chute charge never went off. I learned a lesson at the cost of a beautiful bird - redundancy! I should have used a backup timer!

Summary
Overall I liked the quality of parts. Everything went together well with minimal sanding required for fit. I wish Ky would put more comprehensive instructions in his kits and have them relate to the specific kit they are contained in. To his credit, when I was building Rocketman's Hybrid Mama kit and had questions, Ky sent me his home phone and very graciously answered all my questions personally.

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