One of Aerotech's less popular products is the LMS single-use loadable motors. With certain vendors now requiring Hazmat (correctly) for SU G motors, there may be more interest. I had just bought a 24/40 case and wanted some loads for that, plus a G, so I decided to try one. They are available in 3 versions in G sizes, Green, Red, and White, plus the same sizes as the F econojets, although those aren't Hazmat so I don't understand the reasoning. They do allow for delay drilling and scraping the grain, but that doesn't seem enough to justify them. The Gs are all core-burners so there is no need to tape the grains into alignment.
Assembly is somewhat similar to RMS motors except requires epoxy and CA. There are fewer pieces but some of the fits are very tight, namely the delay grain to the yellow plastic screw closure and the thrust ring. I ended up adding more lube to the O-ring and the inside of the closure just to get it in. This is then screwed into the motor with epoxy (they recomended 5-min., I used the near opposite since all I had handy was WEST). The thrust ring comes seperate and is even tighter. It is attached with CA and it is easy to glue yourself to the case. On the plus side over RMS, no clean-up of the case is required later and you can assemble several in advance without having several RMS cases. But the assembly is somewhat worse.
I got the G79-7W and reduced the delay about 1.5 seconds with a drill bit (a hair less than 1/16", really just a little dent, probably could just use a knife). This is the other reason I tried one, since my rockets don't align with the 4, 7 delays times of SU motors. The 2 grains came stuck inside the motor tube, don't let them fall out on the floor or anything. One end of one grain was highly oxidized (white flecks). I turned them around so the oxidation was on the nozzle end and scraped inside the core hole at the igniter end, though more recently I've scraped more aggresively and over a greater length with RMS slots. It did pulse a couple times before completely lighting. It can't have been real old since it came with a First Fire Jr. The flight itself was excellent.
In conclusion, this is a very niche-y but somewhat useful product. After further reflection on the experience, I have since purchased and flown the 29 mm Hobbyline RMS case. I finally went past the short-long term economic arguments, which annoyed me, and instead considered which has better options in practice for my rockets.
Assembly is somewhat similar to RMS motors except requires epoxy and CA. There are fewer pieces but some of the fits are very tight, namely the delay grain to the yellow plastic screw closure and the thrust ring. I ended up adding more lube to the O-ring and the inside of the closure just to get it in. This is then screwed into the motor with epoxy (they recomended 5-min., I used the near opposite since all I had handy was WEST). The thrust ring comes seperate and is even tighter. It is attached with CA and it is easy to glue yourself to the case. On the plus side over RMS, no clean-up of the case is required later and you can assemble several in advance without having several RMS cases. But the assembly is somewhat worse.
I got the G79-7W and reduced the delay about 1.5 seconds with a drill bit (a hair less than 1/16", really just a little dent, probably could just use a knife). This is the other reason I tried one, since my rockets don't align with the 4, 7 delays times of SU motors. The 2 grains came stuck inside the motor tube, don't let them fall out on the floor or anything. One end of one grain was highly oxidized (white flecks). I turned them around so the oxidation was on the nozzle end and scraped inside the core hole at the igniter end, though more recently I've scraped more aggresively and over a greater length with RMS slots. It did pulse a couple times before completely lighting. It can't have been real old since it came with a First Fire Jr. The flight itself was excellent.
In conclusion, this is a very niche-y but somewhat useful product. After further reflection on the experience, I have since purchased and flown the 29 mm Hobbyline RMS case. I finally went past the short-long term economic arguments, which annoyed me, and instead considered which has better options in practice for my rockets.
, but with the 3/16" drill bit I either round up and measure to the tip, or not quite measure the whole tip. May start drilling a bit more actually. With such short drills it doesn't really get into cutting much material even then, it's more a sort of little dent. It's been working good, both the small adjustments and larger ones.
