Single Use Vs.DMS

[skaffgeorge2]

I might be missing something here but what's the difference between single Use motors and disposable motors?It sounds to me as if they would be the same, but i know there's a catch there somewhere.I 've never flown composite motors so please excuse my ignorance.

 

[OzHybrid]

DMS disposable motor system and RMS reloadable motor system are terms used by Aerotech.
DMS and single use motors are the same. Single use motors as a term includes DMS. DMS as a term refers to Aerotcch disposable motors only usually of APCP composition.
Norm

 

[terryg]

DMS motors allow you to adjust both the delay and the amount of the ejection charge. For single use, what you buy is what you get, you cannot change it.

 

[Scott_650]

Aerotech has factory built single use motors DMS - Disposable Motor System and DIY single use motors LMS - Loadable Motor System. LMS motors are great for learning how to build RMS - Reloadable Motor System though the plastic single use case used for an LMS works a bit different in practice (but not in principle) than the RMS reusable aluminum motor case.

 

[skaffgeorge2]

DMS motors allow you to adjust both the delay and the amount of the ejection charge. For single use, what you buy is what you get, you cannot change it.

Thanks,that's what I thought.Not feeling so dumb after all, lol.

 

[ThirstyBarbarian]

Thanks,that's what I thought.Not feeling so dumb after all, lol.

Yep. That’s it.

Single-use motors come with the delay pre-set to a number of seconds and a standard ejection charge for the motor class already in the charge well. They usually come in a 2 or 3 pre-set delays for each motor type, like G motors with 4- or 7-second delays available, and you buy the one closest to the delay you need.

DMS come with an extra-long delay that you drill down to the delay you want with the delay drilling tool, and they have a vial of powder and the red cap, and you can put in as much or as little as you want.

In both cases, the motor can only be used once and then is thrown away. And in both cases, they are fully pre-assembled for you (with the exception of certain large DMS motors where you do assemble then, which appears to be in keeping with Aerotech’s long-standing policy of coming up with a concept for a sub-brand and then throwing in exceptions to completely invalidate that brand concept).

 

[SolarYellow]

Generally, the ejection charge can be altered or removed on SU composite motors. Just have to pry out the plug and put it back in after making the adjustment. (That is not the case with BP.)

 

[Rocketjunkie]

DMS motors allow you to adjust both the delay and the amount of the ejection charge. For single use, what you buy is what you get, you cannot change it.

Any composite single use motor can have the delay adjusted. Remove the cap and BP, drill through the touch hole, then replace the BP and cap. Most delay grains burn 1/32" per sec. so if you want to take 4 sec. off the delay, drill 1/8". **Make sure you start the drill at the delay grain, not the BP left in the touch hole.** All motors before 1990 were single use, before the introduction of RMS in 1990. We drilled delays then and it worked well.