Smokin' Rockets Mighty Mo

Smokin' Rockets - Mighty Mo {Kit}

Contributed by Greg Lane

Manufacturer: Smokin' Rockets
(by Greg Lane - 02/10/07) (Scratch) Mighty Mo

Brief:
The Mighty Mo rocket is based on the Mega Nuke kit from Smokin Rockets, which is no longer available. I was able to obtain the airframe, nose cone, motor tube, centering rings, and custom cut fins from Red Arrow Hobbies. Since my Dad loves Theatre Organ Music, I named my Mega Nuke after the Mighty Mo Theatre Organ at Atlanta's Fox Theatre. The Mighty Mo was flown for my NAR Level 3 Certification at the 2007 Florida Winter Nationals.

Construction:
The lower airframe is a four foot long 7.5 inch phenolic tube and the upper airframe is a three foot long 7.5 inch phenolic tube. The nose cone is a PML fiberglass cone 29 inches long without the shoulder. I added nineteen ounces of weight in the nose cone. A three inch wide Kevlar® tape was inset at the top of the airframe tubes for zipper protection. The three fins were 3/8 inch birch plywood. The centering rings are 3/8 plywood and motor tube CRs were doubled. The motor tube is 98mm with a Aeropack retainer. I used a 98-75mm adapter for the AMW 1350 motor. The altimeter bay is two separate 54 mm tubes located on opposite sides of the coupler in the upper airframe. The altimeters are on sleds that slide into the 54mm tubes. There are rotary switches located on the sleds which can be accessed with a screwdriver through holes in the airframe. These switches are used to power up the electronics and shunt/arm the ejection charges. There is a Missle Works RRC2 on one sled and a PerfectFlite MAWD on the other. Each altimeter is hooked to separate drogue and main charges. Also, one sled has a Perfectflite MT3G Timer set to fire a backup drouge charge four seconds after the simmed apogee.

(Scratch) Mighty Mo

The airframe was glassed with Aerosleeves 7 inch fiberglass sleeve and West System slow epoxy. I used a rotisserie to rotate the airframe while the epoxy was curing. The weave was filled by Superfill epoxy filler also from Aerosleeves. My main gotcha was using an alignment template for the fins. After expoying the fins, I discovered one was out of line and I had to remove and reposition it. In hindsight, it would have been better to use a plywood fin jig. Six ounce fiberglass tape was placed across the fins roots and motor tube in the fin can.

Finishing:
I used Kilz Original Primer followed by Krylon yellow gloss on the upper airframe and Krylon black gloss on the lower airframe. I consulted Dave Rose of Graphix N Stuff on the color scheme. He suggested a vinyl body wrap that provided a transition from black to yellow on the upper airframe. The body wrap was applied over the yellow upper airframe. This wrap was black vinyl with dots or holes in the vinyl at the bottom and transitioned to dots of black vinyl near the top.

(Scratch) Mighty Mo

SUCCESSFUL LEVEL 3 FLIGHT!

2007 Florida Winter Nationals
Rocket - Mega Nuke kit from Smokin Rockets
Weight - 46 lbs
Motor - Animal Works M1350WW
Altitude - 4340 Feet

Flight:
I did a test flight on an AMW L1300 to 1350 feet with no problems. However, I did decide to switch from a 48 inch chute for the nose cone to a 60 inch chute because it came down at about 28 feet per second. Other than that, I felt well prepared for the cert flight.

I chose an AMW 1350 White Wolf for the cert launch at the 2007 Florida Winter Nationals. The boost on the AMW 1350 White Wolf was fantastic. The altitude reached was 4340 feet which was more than I expected. The drogue charge may have been a little early. I cannot tell if the first charge was an altimeter or from the timer. The main and nose cone chutes deployed for a nice descent from about 1000 feet. The rocket was recovered only about 1/4 mile from the pad with no damage. I now have data from the PerfectFlight altimeter which will help me set the timer for future flights. It was closer to apogee that I planned. I want the altimeters to deploy the drogue and use the timer as a backup.

Recovery:
I chose the Giant Leap TAC-9B for the main chute. The main was in a deployment bag which was pulled off by the nose cone at ejection. The nose cone was recovered separately on a TAC-1 60 inch chute. I used a Giant Leap 24 inch TAC Drogue. I used lengths of two inch wide tubular nylon to get the shock cords out of the airframe for zipper protection. The rest of the shock cord was one inch wide tubular nylon. The drouge harness was 100 feet long and the main harness was 20 feet long.

(Scratch) Mighty Mo I chose to put the switches, altimeter, and batteries all together on each sled to keep the wiring as integrated and short as possible. I am able to pull the altimeter sleds to change the batteries and make the settings without disconnecting any wires. Perhaps a con is the weight of Mighty Mo which kept growing beyond my expectations. As I built it, this rocket weighs 46 pounds without the motor, so it is too heavy for K motors. It needs an L or M with at least 1300 Newtons of average thrust for a stable flight.

Summary:
Even though this rocket was based on a kit, there were no instructions. I needed to make dozens of choices and the materials and techniques. I enjoyed consulting with many level three fliers including John Hansel, Rick Boyette, Joel Rogers, Chris Short, and Lee Brock. Some of the new things I learned were how to fiberglass a large airframe with Aerosleeves, using a timer as deployment backup, using a freebag for deploying the main chute, and applying a large vinyl body wrap.

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