Advice for a Newbie

[jqavins]

OK, not a newbie to rocketry, as some of you know. But a newbie to on-board electronics.

I've been stalled on my L2 build for years, with the airframe done and a confusing, intimidating myriad of options ahead of me for deployment. Obviously I want to keep it simple, but it needs to be adequate and, based on altitude sims, I want it to be DD. Also, the Jolly Logic Chute Release has come out during my stalled period.

Obviously, I ought to try out electronic deployment, dual or not, before the L2 attempt, probably in a mid power or L1 rocket. The rocket I used for my L1 flight had no room inside for any electronics, and disappeared last weekend on a G motor anyway.

My L2 rocket will be a LOC EZ-I65. I have an unbuild Aerotech Initiator for which I might be able to find all the parts to build as a practice platform.

So I'm looking for advice on strategies, devices, and platforms for practice, i.e. is the Initiator a good choice and what else might be better.

 

[Funkworks]

Maybe you can cut your Initiator in two and plug this in:
https://www.apogeerockets.com/Elect...nic-Bays/2-64in-Ebay-Kit-for-Aerotech-RocketsMy first and only DD rocket so far is an Aerotech ARCAS with one of those.

 

[cerving]

If you're looking for a "classic" DD rocket, the Initiator won't do... it doesn't have an AV bay. A 2"-3" FG rocket would be my first choice, something that you can fly on a full H or small I, maybe a 3G 38mm motor. All of the major kit manufacturers make suitable rockets... just make sure they say "dual deploy capable", and it's better if it comes with all of the AV bay hardware so you don't have to go hunting for it. You also want to think about how you're going to mount a tracker, even if you don't have one right now. Nose cone bays are my preferred solution for this... the "John Coker" bay works well.

 

[jqavins]

Thank you both. I may not have been clear, but I'm also looking for advice from a further step back: e.g. products; main above or below the e-bay with the drogue opposite; ditch traditional DD and go chute release; more questions I haven't thought to ask? The options are dizzying. A test platform is only a part of the picture.

 

[Cameron Anderson]

1. Keep traditional DD; main above the av bay, drogue below - that simplifies how you secure the entire airframe.
2. Ditch chute release. It is not advanced per se, but there are pitfalls there that are better avoided while you get experience with electronics. I use chute releases but only in very specific instances - I don't feel they are the first choice when it comes to recovery methods.
3. Electronics...so many options and choice comes down to balancing cost versus personal preference versus capabilities versus size. Simple, cheap, small - RRC2+. Complex, not so cheap, but small - Raven 4. If you can solder and are handy with electronics - eggtimer. Huge capabilities, big, expensive - telemega or AIM XTRA.
For your first DD, you can't to wrong with RRC2+. If you want something easy to use and that will allow you to grow but costs more up front, I recommend Marsa 33.

 

[Buckeye]

I agree, Chute Release is not really on-board electronics in my book. A handy device for sure (I have one), but not much to learn.

I suggest Perfectflight SLCF (small) or Missile Works RRC3 (not so small) as entry level flight computers (~$50) that record data, have computer interfaces, an do 2 channel deployments. After that, get a GPS tracker. The MW T3 is the cheapest system you don't have to solder yourself. BRB900 is solid right out of the box. In fact, the tracker is more valuable than Dual Deploy in getting your rocket back.

Yes, the Initiator is a fine platform to learn. Get an extra coupler, payload tube, and the Ebay kit from Apogee.

 

[jqavins]

I checked out the Apogee link above, and they don't sell the coupler. That's OK, it still sounds like a good plan, getting the coupler from someone else.

 

[JohnCoker]

This video might help (even though the units mentioned are no longer produced):

 

[Bat-mite]

Add my assent to traditional DD. Chute Release is great to have, but I wouldn't want it to be my only DD device. Besides, playing with ematches and BP is fun! There is a whole new aspect of rocketry to learn when designing and building an AVbay. Switch band, vent holes, threaded rods, eye bolts, sheer pins ... rocketry would be a lot less fun for me if that stuff went away.

 

[boatgeek]

A minor dissent to the good advice above. The JLCR is handy in that it doesn’t require a new rocket. You can fly it on anything you already have 38mm and larger, probably in D power or larger. That gives you the opportunity to get practice using your existing fleet. If you think you’d use the chute release on your MPR fleet, it might be worth doing.

If your L2 chute is larger than say 48”, using the chute release may be more difficult. I don’t have experience flying on anything that big.

 

[OverTheTop]

I prefer single-ended dual deploy, but that requires altimeters in the NC and airframe. Standard DD is probably easier to get going on.

Please remember to use PPE when dealing with energetics. I used to use safety glasses, but have found a full faceshield is more comfortable and gives better visibility. YMMV.

The face shield also stops you catching covid off your rocket .

 

[Handeman]

My advice fits what I did, your experience may differ.
I flew my L2 on a K motor and over 6K ft. I used a standard DD setup, drogue below the av-bay and main above. It's still my preferred method.
There are a lot of very good altimeters to use. I prefer Perfectflite, but that's because I've been using them for almost 15 years and am very comfortable with their operation.

Ground testing is usually used to determine the size of ejection charges need to give you the correct deployment and doesn't need to include the altimeter. If this is your first true DD rocket, I would suggest that after you have determined the size of your charges, you hook everything up with the altimeter in place and use vacuum on the av-bay to simulate the flight and test the altimeter and the charges. You can test just the altimeter in a vacuum chamber with LEDs to make sure it works also. By the time you are done with all of that testing, you will be very comfortable with your altimeter and how it works. It will make the DD L2 flight a breeze.