> Model Rockets > Launch Equipment > Misc. : Aerotech Reloadable Motor System 29/40-120 aro91291

Reloadable Motor System 29/40-120

This Model Rocket Motor Reload Kit Contains One Reloadable Motor System (RMS) 29/40-120 Motor Hardware Designed by Aerotech. Federal Law Prohibits the Sale of This Product to Persons Under Age 18.

Aerotech Reloadable Motor System 29/40-120
 Aerotech # aro91291
Retail $69.99  SAVE 9% !
Aerotech Item # aro91291
Specifications :
  • Motor Diameter: 1.13" (29mm)
  • Motor Length: 4.88" (124mm)
  • Assembled Weight: 3.7oz - 5.6oz (104g - 159g)
  • Aerotech Product Number: 91291
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Spotlight Review

"Rocketry's Most Versatile Motor, Bar None"
This is the most versatile rocket motor casing in mid-power rocketry, period, spannng levels E to G with most every propellant formula in the Aerotech arsenal. With proper (and prompt) cleaning and preparation, it will last indefinitely. The aluminum threads on the closures and casing must be thoroughly cleaned of dirt and debris after every use, and I suggest a toothbrush and solvent as needed. Use a liberal application of the recommended synthetic grease on the threads after cleaning. I've only had one CATO with this motor, and that was with the extremely powerful G138 High Power reload, not the mainstream reloads. And the reason was that I didn't apply grease to the liner-less G138's propellant grain casting tube, only to the metal casing. Subsequent assemblies where I DID slather the grease to the G138 grain AND the aluminum casing resulted in perfect performance of the motor casing with no perforation or even scorch marks. I now do this with the outside surface of the liner for all Aerotech reloads, and have found that it helps ensure success. The grease acts as a heat barrier and coolant between the burning propellant and the aluminum skin. Also, assembly-wise, you MUST be sure the installed propellant grain liner can slide easily within the metal casing prior to installing the closures. If it can't, the fore or aft o-rings might not compress properly, giving the flame a direct pathway to the metal casing, which could result in a breach and some pretty spectacular (and disappointing) pyrotechnics bringing down your missile prematurely. If it's too tight a fit, simply peel off the outermost layer of spirally-wound paper from the liner, grease the new outer layer heavily, and retry the fit until the liner slides easily within the casing. This will ensure the o-rings do their job of exiting all that high-pressure propellant flame out the nozzle--NOT the nose cone. Good skies!

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  • For use with RMS 29mm E, F, G reloads.
  • The RMS 29/40-120 motor hardware can be used with Aerotech's E16, E23, F22, F40, F52, G33, G64 rocket motor reloads kits.
  • Primary use in single stage rockets.
  • They deliver power at the lowest per flight cost available in hobby rocketry.
  • RMS motors produce far less non-biodegradable waste than single-use motors.
  • Reflects the same reliablity, quality, and professional design.
  • Assembly and operation instructions provided.
  • Product warranty policies included.


  • Motor Diameter: 1.13" (29mm)
  • Motor Length: 4.88" (124mm)
  • Assembled Weight: 3.7oz - 5.6oz (104g - 159g)
  • Aerotech Product Number: 91291


  • 29mm Aft Closure
  • 29mm Case
  • 29mm Forward Closure
  • Grease

Requirements & Suggestions

  • Motor Reload Kit (Refer to FEATURES)
  • How To Build a Model Rocket
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Write a Review  View All Reviews
"A must have case"
jboldig (Stafford VA)
I bought my first Hobbyline RMS 29/40-120 case in 2003 and have been flying it ever since. A conservative estimate is 120 flights so far and I just ordered another dozen reloads for it. The Yellow silk screen label might be a little worse for wear, but the case itself is just as good as the day I got it. Considering the low cost of the reloads, you can't fly any cheaper than this case. I haven't met any adult rocket hobbyists that don't own at least one of these cases and many of them have two or more.

"Wonderful system- great money saver"
This was my first 29mm case, and it is crazy versatile. It has a massive range of reloads in many different propellant varieties, red, green, blue, black, fast black and white. there is a motor for just about every mid power rocket and flight profile. I have flown mine at least seven times, and plan to fly it plenty more. I have never had a CATO with this motor; there have never been an explosion, blow by, ejection charge failure, or any other type of failure. the best part of this is by far the affordability. the reloads themselves are cheaper than the CTI variety, much less expensive than the single use motors, and this case is, in my opinion, a much better deal than muying the high power style casings. with this one case, you can fly reloads similar to those available with the high power system, but with only one case! Also, with the exception of the F size reloads, all the motors for this ship without Hazmat, as opposed to the CTI version, in which all require Hazmat. This is truly a great system that will save you money, and is the gateway to 29mm mid and high power.

"warning aerotech R7d"
this product has been taking by aerotech because it will go CATO in your rocket only TWO THREADS on forward and aft R&D was at springfest tripoli las vagas 3/21/15 motor went CATO along with aerotech G FORCE rocket head of R&D said there is a problem with 29MM case and 24mm case they took my case 29MM said for research and would get me a new one I PROMISE you to replace it NOPE not yet liars wait for new case with 4threads as said by HEAD OF R&D SAID dont wast your money or your ROCKET


  • This reload kit is intended to be used only with AeroTech Reloadable Motor System Kits.
  • Read and follow the safety codes of the National Association of Rocketry (NAR) and the Tripoli Rocketry Association and comply with
  • all federal, state and local laws in all activities with hobby
  • rockets.
  • Damaged or defective reloads should be returned to Aerotech.

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