RMS casings

[Jerry Irvine]

I was rummaging through the intertubes today and found a Dr. Rocket stub website, a Rouse-Tech site that links back to Aerotech for casing sales, and an AT casing website with little to no available products. Is RMS dead like the latest AT ad implies with employees celebrating a "wind chime" implying RMS casings are done?

[chadrog]

Single use seems to be making a comeback, the wind chime came about under earlier (different) circumstances.

[Jerry Irvine]

U.S. Rockets SU was certainly a thing. 30 years later there are still less than 5K certified users. I had 20k and growing in CA in the early 90's.

[chadrog]

Exactly. You're just too awesome. I don't know how anyone can deny it. All hail the great one. :rolleyes:

[Jerry Irvine]

The future can be different. It is a choice. (Jet hitch) (my sig)

[jetlag]

Reloads are much more trouble than they're worth in my opinion. The pittance saved is far more used up in the time it takes to reload properly. Uses up valuable launching time at an event.
Dumping mine as we speak on EBay...
Allen

[PaulK]

Exactly. You're just too awesome. I don't know how anyone can deny it. All hail the great one. :rolleyes:
:) :)

[ghrocketman]

What is saved by using RMS reloads over SU is NOT a pittance.
I would however argue that SU AP motors SHOULD cost about what RMS loads cost.
I for one find the overall cost of rocket motors to be the most ridiculously over priced item in any hobby other than possibly ammunition.

[jetlag]

Have to agree!

[tab28682]

What is saved by using RMS reloads over SU is NOT a pittance.
I would however argue that SU AP motors SHOULD cost about what RMS loads cost.
I for one find the overall cost of rocket motors to be the most ridiculously over priced item in any hobby other than possibly ammunition.

The costs/savings varies a good bit by motor size.

From buyrocketmotors.com

AT DMS I140 SU........32.29
AT RMS I161 ............26.59

RMS is about 18% cheaper.

AT economax 24mm E20....11.50
AT RMS 24mm E18...............8.33

RMS is about 27.5% cheaper.

I occasionally use a larger DMS motor just to save time at a launch.

If you find hobby rocket motors to be ridiculously overpriced, why don't you get in the rocket motor biz and offer lower cost motors and get rich while putting every other supplier out of business?

[jetlag]

The costs/savings varies a good bit by motor size.

From buyrocketmotors.com

AT DMS I140 SU........32.29
AT RMS I161 ............26.59

RMS is about 18% cheaper.

AT economax 24mm E20....11.50
AT RMS 24mm E18...............8.33

RMS is about 27.5% cheaper.

I occasionally use a larger DMS motor just to save time at a launch.

If you find hobby rocket motors to be ridiculously overpriced, why don't you get in the rocket motor biz and offer lower cost motors and get rich while putting every other supplier out of business?

While I appreciate all you have said, I say, from my standpoint, the extra time spent assembling these motors robs me of more flying time. Not to mention my skills at assembling these RMS motors must be somewhat subpar, because I have lost several rockets to no or insufficient ejectons. I would always find myself puckering up just hoping for an ejection. To me, its just not worth the added anxiety, especially when organized launches are rare enough as it is. When NSL was held near here (finally), I launched in one day 17 times. I don't think I could've done that using RMS, or come home with everything in one piece.
I don't launch high power nor do I ever intend to do so; I can live vicariously through other folks doing that. And there are plenty of failures there, too. I like to see my rockets from launch to recovery!
Plus, now I won't have to worry about losing an expensive casing either.
Anyway, that's my justification for using SU only now.
Works for me beautifully!
Allen

[jetlag]

I will say, however, that if you fly rocket gliders, RMS is really about the only way to go, especially from a cost factor. Then I don't have to worry about no stinkin' ejection charge! Except for the Bomarc or Skydart...well, then it's single use only.
Allen

[bob jablonski]

I like my clusters so I have done more DMS flights. I don't want to buy 3-7 of the same reload cases. Plus since I vend at the launches I go to I don't have a lot of prep time as folks may come up any time and I may forget something.
Mr. Bob
Countyline Hobbies
Grovertown, IN.
574-540-1123
countylinehobbies@yahoo.com
www.countylinehobbies.com

[burkefj]

In addition to 24mm RC RMS rocket glider usage I'm now running plugged forward closures and using electronics on all my highpower flights, reduces one failure mechanism...and they are less expensive, and not trivially so..

In 20 years of flying I've had one forward failure of a 38mm ez rms front end and two excess thrust issues in 32mm G12 reloads that had voids in them. I've not had any issues with rms reload delay times.

For single use I've had numerous (four or more) failures of casings in G-38's and G-40's, long delays in 24mm motors, and thrust rings that I had to bolster with glue on DMS casings...

[tbzep]

If Aerotech had started life with simple hardware, a lot of you would have been much more successful. I know back in the day Ron Urinsco, Kosden, and Dynamic Propulsion Systems used a simple single o-ring (on smaller motors) in a groove on the nozzle and bulkhead, using a single snap ring to hold them in. The delay bulkhead was simple also. I assume JI's motors are the same, but I've never seen any disassembled in person. Larger motors sometimes used more o-rings for redundancy, but they are super simple to put together and only fail when the assembler completely forgets the o-ring or silicone grease. The first time I saw in person the screw-in bulkheads and nozzle assemblies, press fit o-rings, etc. I understood why there were so many failures in Aerotech hardware. I'd already been using Jim's (DPS) hardware for a long time and could put together a motor in about a minute or maybe two if I had to think about how deep I wanted to drill the delay. :cool:

[ghrocketman]

I might be the only one to say this, but I have NEVER had a failure of ANY RMS reloads.
There have been a few slightly long/short delays, but nothing that has ruined anything.
I take my time to assemble them CORRECTLY to the instructions.
Random/Haphazard assembly causes almost all RMS failures.
They are NOT that complicated to assemble, folks.
If you can assemble a skill level TWO rocket, you CAN correctly assemble Aerotech RMS loads.
Reloads for the other so-called 'simpler' brands are priced as high as some SU motors, which is just plain a$inine.

[tbzep]

I might be the only one to say this, but I have NEVER had a failure of ANY RMS reloads.
There have been a few slightly long/short delays, but nothing that has ruined anything.
I take my time to assemble them CORRECTLY to the instructions.
Random/Haphazard assembly causes almost all RMS failures.
They are NOT that complicated to assemble, folks.
If you can assemble a skill level TWO rocket, you CAN correctly assemble Aerotech RMS loads.
Reloads for the other so-called 'simpler' brands are priced as high as some SU motors, which is just plain a$inine.
And that seems pretty stupid considering how much more simple they are to make and use. Some of them may be making them by hand instead of farming them out to automated machine shops, making them more labor intensive and therefore more expensive.

I guess you can make a case that the solid graphite nozzles are more expensive than the Aerotech inserts, but the rest of the design is simple and cheap. Everything was reusable on ours, even the o-rings for the nozzle and bulkhead. We migrated from black buna to orange silicone o-rings, which were more expensive, but still very cheap considering they could be reused. We did throw out the little o-ring that we stuffed in the bulkhead ahead of the delay grain, but that's it. We used our graphite nozzles many times also. Once they eroded too far, we'd drill them out to the next power level and use them several times again. The only time there was ever severe erosion was when we did titanium sparky motors.

[PaulK]

Another RMS user that never had a failure, until RMS-EZ came along, and that was due to a faulty EZ delay from AT the first (and last) time I used one. There was (and maybe still is) an issue with the epoxy sealing the delay. I prefer to assemble all the pieces, so I have maximum control over the assembly. OTOH, I've had numerous failures of the plastic case SU motors (Econo-Jet up through G80). The plastic case simply isn't strong enough, so I rarely use those motors anymore. For DMS, the ease-of-use is great when time is limited - but I've only flown 3 of them, on beater rockets, to try them out. At least the DMS cases are glass reinforced, but I still wouldn't trust them on one of my 'good' rockets.

[ghrocketman]

I also trust MYSELF to assemble reloads correctly more than I trust SU motors to be factory mass-produced correctly.