Aerotech 29mm RMS Motor

Aerotech - 29mm RMS Motor {Motor}

Contributed by Alex Rothchild

Overall Rating: starstarstarstarstar
Manufacturer: Aerotech

Rocket PicBrief:
This is a 29mm aluminum motor casing, for motors with 40-120 Newton Seconds total impulse (ranging from E to G). It is a bit pricey at $50 for the casing, but a G motor costs only $10-12 instead of $20 or more for a single use motor of the same total impulse.

Construction:
The casing is only three pieces, a long casing, a forward closure, and an aft closure, both of which screw into place in the casing.

A reload kit though, contains many different parts however. Each reload kit has the following parts:

  • 1 nozzle
  • 2 29mm x 1/16" rubber O-rings
  • 1 liner tube
  • 1 propellant slug
  • 1 spacer tube
  • 1 forward insulator ring
  • 1 delay liner
  • 1 delay spacer (for motors with delays shorter 10)
  • Delay material
  • 1 thick O-ring
  • Ejection charge
  • Copperhead igniter

Construction is quick and simple. Just follow the reload assembly instructions carefully and you shouldn't have a problem. The first step is to apply grease on each O-ring, and push the smaller one into the front of the forward closure. Put the larger diameter O-rings aside. Then slide the delay material into the delay liner and push the spacer into place under it (and don't get grease on the delay assembly). The spacer part should be face down. Put this assembly aside. Then take the propellant slug, the spacer tube, and the liner tube, and put the spacer and propellant into the liner. The only step I did not like is for E and F engines masking tape needs to be put at the top of each propellant slug so that the igniter does not go all the way inside the engine. Put this assembly inside the main casing. Put the insulator ring on top and then a greased 29mm O-ring. Screw the forward closure on top of this tightly. Then, flip it over and place the nozzle into the motor. Put the last O-ring on the bottom of the nozzle and screw the aft closure into position. It should be tight. Next, take the delay charge and put it on top of the forward closure so that it snaps into position. Insert the igniter and either tape it or used the supplied nozzle cover to hold it in position. I prefer the cover piece, although that requires a small vent hole to be cut in it. Construction is extremely simple and will work if instructions are followed and all the rings are in the right position.

Finishing:
No finishing had to be done for this, but it comes all black with the words Aerotech Aerospace painted in gold on the side, and the aft closure is gold.

Flight:
The countdown for your first reload will be the longest 5 seconds of your life. My first flight was my LOC Onyx on an E23-5T. It lit up almost instantly and shot off the pad to around 600 feet. Perfect flight and recovery. After waiting a few minutes for it to cool off, which was much faster than I expected, I unloaded the engine by simply screwing both closures off and pushing out the assembly. I cleaned out the inside of the casings and closures with Wet Wipes and then dried them with paper towels. Next I loaded a F40-4W for my LOC Forte, which I call the Pirate Rocket. It flew, but only after about 4 tries to light it with a Copperhead igniter. It finally lifted off and flew perfectly. The chute didn't open, so it came down hard. The nozzle was pushed up inside the casing, but there was no damage to either the rocket or casing. The third flight of the day was a G64-4W in my LOC-IV. This is a great motor this rocket. It lit on its first attempt and roared off the pad.

Summary:
This is great system to save money on mid power engines. Just follow the instructions and it should work. Make sure all the O-rings are in the right place and nothing will go wrong. People always talk about all the failures they have with RMS motors, but they are easy to avoid if all the directions are followed.

Overall Rating: 5 out of 5

Other Reviews
  • Aerotech 29mm RMS Motor By Geoffrey Kerbel

    (by Geoffrey Kerbel - 12/12/06) Brief: The AeroTech 29MM RMS is a reloadable motor casing for mid-power flights with "E" through "G" power reloads. This is a system that allows the flier to put their own motors together with the power requirements to suit their rockets power capabilities. AeroTech calls this their hobby loads and no special certification is needed ...

Comments:

avatar
J.L. (December 23, 2006)
This is a great casing because of the flexibility. The option of E, F, or G loads is excellent. One of the drawbacks, though, is weight. Compared with the 24mm casing (which takes E and F loads), the 29mm is a lot heavier. So you only get 50% or so more altitude with a G load over a 24mm F, not double like I assumed at first blush.

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