Composite Staging Electronics...

[Bruiser]

I really enjoy flying two stage rockets and have been very successful with gap staging 29mm Estes motors. I think I am ready to try staging composites now, The thing that has held me off is the electronics. I'm not really very "tech-savvy".

I have been eye-balling the LOC Terrier Sandhawk and I saw that Apogee has an electronics sled available for it. I've watched the ten videos Tim has covering the building of the rocket and I has inspired me because the electronics he uses seem very simple if used as they are preset. In other words, you do not necessarily need to hook up a laptop to configure them. Here is a pic of the ebay


It uses a Simple Timer for the air start and an EZ Mini Altimeter for the dual deploy. The Terrier Sandhawk is a little too large for me right now because I'm pretty sure I would need to be level one to fly it but I thought I could use this same set up on a smaller rocket that could fly with maybe a F to F or a G to F configuration like maybe a two stage Doorknob.

I have already bought the Simple Timer and was just planning on using it in the rocket but then I got to thinking... What if the second stage doesn't ignite? Then I would at the very least, lose the sustainer when it impacted terra firma...

So I have come to the realization that I do need an altimeter. I wanted to ask if there are any other small altimeters I should consider? I am only planning to single deploy at apogee and let the JLCR do the rest.

Thank you for reading,
-Bob

 

[mbeels]

Hello Bob,

The absolute simplest for apogee only deployment is the Eggtimer Apogee. No configuration required.

http://eggtimerrocketry.com/home/altimeters-av-bay/

 

[boatgeek]

Another good option if you don't want to do self-assembly is the Missileworks RRC2+. It's small and simple to use for dual deploy.

 

[Howitzer]

I used a MARSA33 with gyro tilt module for my LOC Terrier Sandhawk and used the standard avbay layout.

 

[JimJarvis50]

Bob,

Two-stagers are fun! If you have any thoughts about building larger two-stagers that would require high power certification, I would recommend that you use an altimeter that has an altitude check capability. You have to set an altitude, but the point is that the rocket has to reach that altitude or the sustainer won't light. It's a simple safety measure even for mid power rockets. The RRC2+ has the capability to do this and others do as well. An alternative is something like the Altus Metrum easytimer that uses tilt rather than altitude, but accomplishes a similar safety goal. You want the sustainer to light "if appropriate" and not "no matter what".

Jim

 

[Titan II]

The RRC2+ has the capability to do this....

It is the RRC3 that has the capability.

 

[JimJarvis50]

It is the RRC3 that has the capability.

Ah, thanks for the correction. I don't own either one, but I know the "brand" has the capability.

Jim

 

[Bruiser]

I have the Simple Timer to handle the sustainer air start. I just need something to deploy the chute should the air start not happen.

I think I can solder up the Eggtimer Apogee but then I also need to get a separate terminal block for connecting the firewire. I wish Apogee had one on the board like their Quark. The nice thing about the APogee is that it uses the same size battery as the Simple Timer. I would consider the Quark but it uses 2s batteries.

-Bob

 

[rokit]

I use my Quark with 1s lipos. Fully charged they're over 4v and work fine.

You can solder either stranded or solid wire to an Apogee, then twist your ejection charge to that wire, on either side of the av bay bulkhead.

 

[cerving]

Be advised that the newer version of the Quark will NOT work with a 1S LiPo... the output drivers require a minimum of 4.5V. There is an undervoltage shutdown at 3.5V-4.5V per the spec, so it's possible that even with a fully charged 1S LiPo at 4.2V it won't switch on your outputs.