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Motor and Reload Designs
You Can Use

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The following is a list PVC pipe motors and reloads for commercial motors that you can make. You can use these motor and reload designs as a starting point and modify them for your rocket using CP Technologies software program FPRED. Your propellant burn rate coefficient and burn rate exponent are likely to be different depending on the particle sizes.

PVC Pipe
Single Use Motors

1.25 Inch PVC Pipe

All of these motors use 1 inch PVC pipe for the propellant cartridges. There is no insulation required inside the 1.25 inch PVC pipe. The 1 inch PVC pipe propellant cartridges are have tapered propellant ends and the cartridges are taped together using electrical tape. Assembly procedures and how to mix and cast the propellant are described in "How To Make Amateur Rockets". One nice thing about 1.25 inch PVC pipe motors is that they fit nicely inside 54mm motor mounts, if you wrap a couple of layers of duct tape around the end cap and nozzle fittings.

    Parameters
  • Propellant: 20% R20LM, 20% -650 mesh Magnesium, 60% Ammonium Nitrate powder, Rubinate M Curing Agent
  • Number of cartridges = 5
  • Bore diameter = 7/16 inch
  • Cartridge length = 1.5 inches
  • Throat diameter = 0.25 inches
  • Throat material = CE phenolic embedded in Durham's Water Putty
  • Burn time = 5.75 seconds
  • Average pressure = 104 psi
  • Maximum pressure = 156 psi
  • Average thrust = 6 lbs
  • Initial thrust = 7.7 lbs
  • Maximum thrust = 8 lbs
  • Total impulse = 151 Newton - seconds
  • Propellant weight = 0.282 lbs

    Parameters
  • Propellant: 20% R20LM, 20% -650 mesh Magnesium, 60% Ammonium Nitrate powder, Rubinate M Curing Agent
  • Number of cartridges = 6
  • Bore diameter = 3/8 inch
  • Cartridge length = 1.75 inches
  • Throat diameter = 0.25 inches
  • Throat material = Graphite embedded in Durham's Water Putty
  • Burn time = 3.25 seconds
  • Average pressure = 322 psi
  • Maximum pressure = 365 psi
  • Average thrust = 16 lbs
  • Initial thrust = 13 lbs
  • Maximum thrust = 18 lbs
  • Total impulse = 229 Newton - seconds
  • Propellant weight = 0.417 lbs
    Parameters
  • Propellant: 20% R20LM, 20% -650 mesh Magnesium, Ammonium Nitrate powder, Rubinate M Curing Agent
  • Number of cartridges = 10
  • Bore diameter = 7/16 inch
  • Cartridge length = 1.75 inches
  • Throat diameter = 0.3125 (5/16) inches
  • Throat material = Graphite embedded in Durham's Water Putty
  • Burn time = 2.5 seconds
  • Average pressure = 421 psi
  • Maximum pressure = 466 psi
  • Average thrust = 32 lbs
  • Initial thrust = 28 lbs
  • Maximum thrust = 36 lbs
  • Total impulse = 362 Newton - seconds
  • Propellant weight = 0.66 lbs

2 Inch PVC Pipe

All of these motors use 1.5 inch PVC pipe for the propellant cartridges. There is no insulation required inside the 2 inch PVC pipe. The 1.5 inch PVC pipe propellant cartridges are have tapered propellant ends and the cartridges are taped together using electrical tape. Assembly procedures and how to mix and cast the propellant are described in "How To Make Amateur Rockets".

    Parameters
  • Propellant: 20% R20LM, 20% -650 mesh Magnesium, 60% Ammonium Nitrate powder, Rubinate M Curing Agent
  • Number of cartridges = 6
  • Bore diameter = 0.75 inch
  • Cartridge length = 2.25 inches
  • Throat diameter = 0.375 inches
  • Throat material = Graphite embedded in Durham's Water Putty
  • Burn time = 4.25 seconds
  • Average pressure = 277 psi
  • Maximum pressure = 314 psi
  • Average thrust = 31 lbs
  • Initial thrust = 32 lbs
  • Maximum thrust = 35 lbs
  • Total impulse = 580 Newton - seconds
  • Propellant weight = 1.1 lbs
    Parameters
  • Propellant: 20% R20LM, 20% -650 mesh Magnesium, 60% Ammonium Nitrate powder, Rubinate M Curing Agent
  • Number of cartridges = 7
  • Bore diameter = 0.75 inch
  • Cartridge length = 2.25 inches
  • Throat diameter = 0.375 inches
  • Throat material = Graphite embedded in Durham's Water Putty
  • Burn time = 3.5 seconds
  • Average pressure = 401 psi
  • Maximum pressure = 462 psi
  • Average thrust = 44 lbs
  • Initial thrust = 47 lbs
  • Maximum thrust = 51 lbs
  • Total impulse = 693 Newton - seconds
  • Propellant weight = 1.28 lbs

2.5 Inch PVC Pipe

All of these motors use 2 inch PVC pipe for the propellant cartridges. There is no insulation required inside the 2.5 inch PVC pipe. The 2 inch PVC pipe propellant cartridges are have tapered propellant ends and the cartridges are taped together using electrical tape. Assembly procedures and how to mix and cast the propellant are described in "How To Make Amateur Rockets".

    Parameters
  • Propellant: 20% R20LM, 20% -650 mesh Magnesium, 60% Ammonium Nitrate powder, Rubinate M Curing Agent
  • Burn rate coefficient = 0.0061 in/sec and burn rate exponent = 0.507
  • Number of cartridges = 9
  • Bore diameter = 1.125 inch
  • Cartridge length = 2.5 inches
  • Throat diameter = 9/16th (0.5625) inches
  • Thrust coefficient = 1.13
  • Throat material = Graphite embedded in Durham's Water Putty
  • Burn time = 4.47 seconds
  • Average pressure = 240 psi
  • Maximum pressure = 278 psi
  • Average thrust = 60 lbs
  • Initial thrust = 69 lbs
  • Maximum thrust = 70 lbs
  • Total impulse = 1272 Newton - seconds
  • Propellant weight = 2.55 lbs

4 Inch PVC Pipe

All of these motors use 3 inch PVC pipe for the propellant cartridges. There is thin layer of insulation (0.06 inch thick) required inside the 4 inch PVC pipe. The 3 inch PVC pipe propellant cartridges are have tapered propellant ends and the cartridges are taped together using electrical tape. Assembly procedures and how to mix and cast the propellant are described in "How To Make Amateur Rockets".

    Parameters
  • Propellant: 20% R20LM, 20% -650 mesh Magnesium, 60% Ammonium Nitrate powder, Rubinate M Curing Agent
  • Number of cartridges = 12
  • Bore diameter = 1.902 inch (1.5 inch PVC pipe wrapped with wax paper)
  • Cartridge length = 2.5 inches
  • Throat diameter = 0.875 inches
  • Throat material = Graphite embedded in Durham's Water Putty
  • Burn time = 7 seconds
  • Average pressure = 206 psi
  • Maximum pressure = 362 psi
  • Average thrust = 124 lbs
  • Initial thrust = 217 lbs
  • Maximum thrust = 217 lbs
  • Total impulse = 3866 Newton - seconds
  • Propellant weight = 6.96 lbs

Homemade Aerotech
Reloads

One of the interesting things we found in static firing this motor is that the throat is hardly eroded with the cool burning AN propellant. These nozzles could be reused with a small increase in the bore diameter to maintain similar motor performance between firings.

    Parameters
  • Propellant: 20% R20LM, 20% -650 mesh Magnesium, 60% Ammonium Nitrate powder, Rubinate M Curing Agent
  • Motor hardware = RMS 38/720
  • Number of cartridges = 6
  • Bore diameter = 0.375 inches
  • Propellant outer diameter = 1.268 inches
  • Cartridge length = 1.844 inches
  • Throat diameter = 0.2570 inches
  • Throat material = RCS phenolic nozzle
  • Burn time = 3.25 seconds
  • Average pressure = 624 psi
  • Maximum pressure = 776 psi
  • Average thrust = 49 lbs
  • Initial thrust = 44 lbs
  • Maximum thrust = 61 lbs
  • Total impulse = 606 Newton - seconds
  • Propellant weight = 0.65 lbs

Homemade Kosdon
Reloads

The nice thing about using Kosdon hardware for your experimental motors is that the nozzles are graphite and do not experience any throat erosion when using AN propellant. You can reuse the nozzles almost indefinitely.

    Parameters
  • Propellant: 20% R20LM, 20% -650 mesh Magnesium, 60% Ammonium Nitrate powder, Rubinate M Curing Agent
  • Hardware = Kosdon 54/1400
  • Number of cartridges = 4
  • Bore diameter = 0.5 inch
  • Propellant outer diameter = 1.754 inches
  • Cartridge length = 3.0 inches
  • Throat diameter = 0.359 inches
  • Throat material = Kosdon graphite nozzle
  • Burn time = 6.5 seconds
  • Average pressure = 298 psi
  • Maximum pressure = 345 psi
  • Average thrust = 42 lbs
  • Initial thrust = 30 lbs
  • Maximum thrust = 49 lbs
  • Total impulse = 1089 Newton - seconds
  • Propellant weight = 1.358 lbs