Public Missiles - Bumble Bee {Kit} [?-]

Contributed by Kathy Kippen

Construction Rating: starstarstarstarstar
Flight Rating: starstarstarstarstar
Overall Rating: starstarstarstarstar
Published: 2015-04-13
Diameter: 3.90 inches
Length: 35.50 inches
Manufacturer: Public Missiles

Brief

A new offering from Public Missiles, LTD, the Bumble Bee is a short stubby mid-powered rocket. It’s a straightforward build with a few new features that include a recovery tube and a new style nosecone with the strap imbedded in the nosecone tip as well as new construction methods.

Components

  • 1 pre-slotted main airframe
  • 1 recovery tube
  • 1 nose cone
  • 3 fins
  • 1 piston ejection kit:
    • 1 piston tube
    • 1 slotted bulk plate
    • 1 ¾” wide piston strap
    • 1 d-ring
  •  1 parachute
  •  1 motor mount tube
  •  2 recovery tube to airframe centering rings
  •  1 airframe to MMT centering ring
  •  1 notched recovery tube to MMT centering ring
  •  1 shock cord
  •  2 launch lugs
  •  1 decal sheet
  •  1 instruction booklet

Construction

To begin, I sanded all parts and test fit all components and scuffed the QT inside and out for better epoxy adhesion. 30 minute epoxy was used for all construction.

 

First up was to build the motor mount as per the booklet instructions noting the small notched centering ring is at the top and gets epoxied into the bottom of the recovery tube in a later step. Add fillets after ring is dry. After this is to thread one end of the piston strap thru the notch in the upper CR and epoxy into place and let dry.

 

Next is mounting the recovery tube to airframe CR’s onto the recovery tube as directed in the instructions, adding the required fillets around both rings and let set.

 

At this step of the instructions read and reread to make sure you fully understand the next step as it has to be completed in one quick motion after the epoxy is spread inside the airfram tube. Push the recovery tube into the top of the airframe and use the nosecone to push the recovery assembly into place to make sure the nosecone seats against the airframe properly. Being afraid of accidentally gluing the nosecone to the airframe, I carefully removed it and left the airframe/recovery assembly to set. I also used a long dowel to do the fillet on the top CR being very careful not to get epoxy on the inside of the airframe.

 

After that fillet has set up, time to install the mmt as per the instructions.  Then on to mounting the fins and adding fillets inside and out. PML suggests pouring expanding foam between the fin tabs. I opted not to do this step and just installed the bottom CR in place making sure it was seated against the fin tabs.

 

Build the piston as per the instructions and connect up the recovery strap to the d-ring on the piston. Attach the parachute as indicated.

Finishing

I used standard rail buttons in place of the included lugs and mounted them as per the instructions for location after painting the rocket. The kit comes with the stripe decal. I added the face to add character

Construction Score: 5
 

Flight

First flights were on CTI Pro38 G79SS and G115WT for awesome flights. I’m hoping to get a few flights in on H and I motors when launch season resumes.

Recovery

The kit came with a 48" PML parachute. For the fields I fly in, it's the proper size for soft landings.

Flight Rating: 5

Summary

A good size rocket for smaller fields on smaller 38mm motors.

Overall Rating: 5

Comments:

avatar
Brian Ditmer (January 30, 2020)

How did you go about mounting the rail buttons? I put one on the very low end of the tube. But the spot where I wanted to put the second button would block the nosecone. I've though about cutting a groove in the nosecone to accommodate the button screw, Not sure what effect that might have though.

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