RMS and Dual Deploy Questions

I have a Dr. Rocket 38mm motor set that has the normal foreward end with the hole and the ejection charge well.
I would like to modify my rocket to dual deploy using electronics for both drogue and main deployment.
I'm figuring that I will need to get the plugged end for this; correct?
Then just not use the delay and ejection charges.
Could a person use the ejection charge that comes with the reload as either one of the charges in the dd?
Anyone have a Dr. Rocket 38mm plugged front end they want to get rid of?

Thanks,

Greg

You can use the standard closure with no problem. Fill the well with wadding and cap it with tape. You could use motor ejection for apogee separation, but electronics will ensure you are at apogee when it separates, which is a good thing.

Whether you use the normal forward closure or the plugged forward closure - USE THE DELAY GRAIN! Just leave out the ejection charge.

What they said.....and I use the normal forward closure all the time in that manner and it works fine.

Greg,

Where in Iowa are you and where do you launch at..?

I'm not sure I even always have plugged mine, but what I said earlier is safe. And yes, you need the delay grain!

Originally posted by jcrocket
Pop your drogue out the section nearest the fincan. Then use a long delay to pop the drogue if the alt doesn't do it's job at the top. You can at least avoid a ballistic recovery in the event of an electronics failure.

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You can do this. However, once you are comfortable with electronics, you will find the chance of electronics failure is less than a premature ejection or blowby. Using a plugged forward closure eliminates any chance of this failure mode.

Ahh, good point. Obvious but I have never thought of it. That's what I get for never suffering a CATO.....finding some wood FAST!

Two points.

1) You must use the delay element even with a plugged forward closure.

2) Don't use the plugged closure. Just use a delay which is longer than your expected time to apogee. This will provde some redundancy in case the electronics fail. Which they do from time to time.

I have been using RMS motors since 1996 and electronics for not quite as long. In that time I have not experienced a single forward closure failure but I have had an altimeter fail to deploy at apogee once.

Alas, I had installed the backup timer (it was a hybrid flight) upside down so its acceleration switch failed to function. I got lucky in that the rocket decided to come down sideways and the main deployment charge did work.

Originally posted by firemanup
What they said.....and I use the normal forward closure all the time in that manner and it works fine.

Greg,

Where in Iowa are you and where do you launch at..?

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I'm in Rockford, just SE of Mason City; IIRC you're in Nevada or Story City, so not really far at all.
So far the only launch I've been to (and launched) was last month in Maple Island, MN; met BHP there and saw his BLU. AWSOME.
It was also where I did my level one; now just waiting on the stuff from TRA.
I am looking at seeing about getting a waiver for somewhere around here so that I can fly when I want.
Should get together sometime, I'd like to see your fleet.

I also think we should see about getting the IA folks together sometime as well.
You are really quite centrally located, if you know of a place close to you to launch, maybe we could all link up at a hotel in Ames some weekend.

Greg

I have used plugged closures without the delay ( I didn't have one). I just filled the well with grease and it was fine. I would use the delay, if I had the choice. I also use the motor ejection as a back-up for the dual deployment. Just get the delay time right or a little long.