Madcow Rocketry HoJo 50

Madcow Rocketry - HoJo 50 {Kit}

Contributed by Keith Hamel

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Manufacturer: Madcow Rocketry
Madcow Rocketry Honest John M50

Brief:
The Madcow HOJO M50 mid-power rocket kit is a fun kit to build and fly. The kit comes with precise laser cut parts and all of the extras. If you were talking about a car, you would say it is loaded. Madcow kits tend to be priced on the higher end but well worth it!

Construction:
Parts list:

  • 1 custom balsa nose cone
  • 1 custom balsa transition
  • 1 custom balsa tail cone
  • 1 pre-slotted body tube
  • 1 centering ring
  • 1 29mm motor tube
  • 4 laser-cut fins
  • 1 eye bolt, nut, and washer
  • 1 NC shoulder coupler
  • 1 NC shoulder bulkhead
  • 1 Kevlar® shock cord section
  • 1 nylon shock cord section
  • 1 flameproof chute protector
  • 1 24" Nylon chute
  • 2 ¼" launch lugs
  • 2 launch lug spacers

I purchased two kits from Madcow, and they arrived well packed and in excellent shape. Inside the heavy plastic bag, the balsa nose cone and boat tail were wrapped in heavy corrugated paper with separate bags for the smaller parts.

The straightforward instructions are printed on five sheets of 8.5" x 11" paper folded in half. Five minute epoxy is suggested for the entire build, but it could also easily be built using yellow wood glue. I used a combination of thirty minute epoxy (it is what I had) and Titebond II wood glue. I used the epoxy to build and install the motor mount as well as the nose cone and coupler and wood glue for the fins and fillets.

Madcow Rocketry Honest John M50 I started with the nose cone and boat tail. The two piece nose cone requires a 1 inch wide by 1.5 inch hole drilled in the wide end of each piece for the lead weight, 4oz in each hole. Once the epoxy is cured, the two pieces need to be joined with epoxy, although you could certainly use wood glue. It is critical to make sure the pieces are joined evenly and do not wobble when you spin it. While the nose cone was curing I applied water diluted Elmer's Wood Filler to the boat tail and nose cone once it was cured then sanded both smooth using 320 grit sand paper. They both got 3 coats of Minwax Polycrylic sanding lightly in between each, leaving a nice smooth finish. The next step for me was the nose cone shoulder/ballast box using epoxy. This consists of a nose cone shoulder, eye bolt, washer and nut. Once assembled the unit is epoxied to the base of the nose cone.

The rest of the build is straightforward. I tapered the leading edge of the fins and filled and sanded them smooth (not that they required it). I built the motor mount with epoxy tying the Kevlar® to the motor tube and feeding it through the notch in the centering ring making sure the centering ring and boat tail line up with the fin slots. Once cured, I installed it in the body tube with epoxy. The fins are installed into the slots, and the fit and finish of these parts is fantastic. Here I used Titebond II wood glue.

Finishing:
There are no suggestions for finishing the M50, except for the picture on the instructions. I found details online. I primed the entire rocket with Kilz, sanding most of it off with 220 grit, 400 grit, and 600 grit sandpaper, leaving a smooth finish for paint. I painted the entire rocket with Rustoleum Painters Touch semi-gloss white. Allowing the rocket to dry thoroughly it was then masked and three fins were Rustoleum Painters Touch painted gloss black. The nose cone was also masked and painted Rustoleum Painters Touch light gray gloss then Rustoleum Painters Touch gloss black. The stripes were cut from Top Flite Trim Monokote.

Construction Rating: 4 out of 5

Madcow Rocketry Honest John M50

Flight:
For the first flight I chose a Road Runner F60R-4, which is not a recommended motor but according to RockSim a perfect choice. The motor was friction fit with masking tape wound around the motor in a spiral. The chute was packed inside the Nomex® pad; both were attached to the shock cord. The two wire igniter was inserted and held in using masking tape around the nozzle with two small cuts for venting. The motor lit launching the M50 in 8-15mph winds. There was a nice initial boost but the M50 corkscrewed a bit on the way up, and ejection took place at apogee. It is hard to say what caused the corkscrew, as it could have been rod whip or builder error (nose cone balance). Other than that it was an impressive flight. It will fly again.

Recovery:
Recover was perfect. It was a nice gentle landing under the 24" nylon chute with no damage.

Flight Rating: 4 out of 5

Summary:
The Madcow Honest John M50 is an impressive kit with high quality parts. The fit, finish and laser cutting are second to none. Some may question the lack of motor retention, but I think friction fitting works just fine. The one tricky part to the build is the two piece nose cone. Other than that, the build is uncomplicated. This is good kit for first time mid-power builders. The M50 can be launched on a wide selection of F and G 29mm motors. This is an excellent kit and is well worth your rocketry funds.

PROs:

  • High quality parts, excellent laser cutting, fit and finish
  • Good instructions making for an uncompleted build

CONs:

  • Lack of motor retention for some, does not bother me
  • Price but this kit is money well spent
  • The nose cone could be less complicated if the nose weight was preinstalled.

Overall Rating: 4 out of 5

Flights

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