3" build - Dual Deploy and glass practice prior to L3

[Dustin Lobner]

Got it all put together. 3.5 calibers stability with the J450 loaded. Final dry weight comes in at 4.7kg with everything except the 9V batteries and charges installed, so my guess of 4.8kg was pretty much dead on.

Do people normally find on 3" dia rockets that the tubes for the recovery stuff are basically jammed packed to the top? I'm a fan of long shock cords, and she's full up to the top at both ends. Does that change my BP calculations for BP quantities? Doing ground testing tomorrow so I guess I'll find out one way or another.

RockSim says 3700 feet on a J450, 5700 feet on the K535 that's waiting for me with Wildman.

 

[Dustin Lobner]

Deployment testing tonight was a mixed bag. I couldn't get either of the Quantums to work right, issues with the webpages loading and whatnot. My phone can be a bit of a dunce at times, so I'm going to try a different device when I can.

On the mechanical side, I hotwired one charge and blew the nosecone and recovery harness over my friend's apple tree, so I think I'm good there. I'll run that same charge this weekend if I can get the quantums working right. The 3D printed charge canister was completely unscathed, so that whole setup is good to go.

 

[wsume99]

On the mechanical side, I hotwired one charge and blew the nosecone and recovery harness over my friend's apple tree, so I think I'm good there.

LoL

Good news on the charge canister too. It has to be satisfying when something works as you intended.

 

[Dustin Lobner]

Still can't get the Quantum's working...They arm and disarm fine, but the test page doens't actually test them. Waiting to hear back from Cris, and started printing a 54mm motor retainer for my L2 rocket so I can fly the J450 in that if I can't get the Quantums working. Not dual deploy, so not checking that box for L3 prep, but the summer is long. Will get there eventually.

 

[Dustin Lobner]

Updates - the flight computers are behaving. As expected, User Error 101. The IP address for the flight computers is 192.168.4.1...to go to deployment testing, you go to 192.168.4.1/test I was putting that in as /test/ with the extra "/" at the end, which causes the test page to display but nothing to actually work.

That problem solved, I fired an ematch on each channel and confirmed that the computers are firing correctly. Going to get everything put together and ready to go, then flying this one at Mini Midwest Power tomorrow. The weather forecast was marginally better tomorrow over today, so troubleshooting going into today wasn't the worst thing to have happen.

A charge of 1.6 grams was good for the main tube (when I shot the nosecone and main recovery hardness over the apple tree). I have 1.5, 1.6, and 1.75 charges made up. Think I'm going to go with 1.5 primary, 1.6 backup on the drogue side and 1.6 primary, 1.75 backup on the main side. Drogue side has 5" less tubing and 2 less shear pins, so shouldn't be a problem.

Also an aside - Cris at Eggtimer is fantastic. We exchanged 20+ emails on this one, he was patient with me the whole way, was logical in the approach we took and whatnot. I know DIY electronics aren't for everyone, but for those of you who are, I recommend Eggtimer and Cris without hesitation (and in fairness to Cris, in the instructions, he has in bold, 192.168.4.1/test without the / at the end...I brought this one on myself by adding the /).

 

[Dustin Lobner]

Basket Case flew today at Mini-Midwest Power! Pretty much perfect flight, with the exception of the streamer I had planned to use as the drogue got wrapped around the nylon strap and she came down FAST from altitude. Main opened at 700 as planned and all is well.




A couple more pics of the avionics bay sled:




People were wondering about whether or not the motor casing would melt to the PLA. At least for a J450, the answer is no.




Last night I was worrying about the BP charges burning on the end of the nylon cord, so I hot glued a nomex "baffle" on each end, which worked really well.

 

[wsume99]

Congrats on a successful launch. Really glad to hear everything survived. Are you planning any more powerful launches?

 

[Dustin Lobner]

Congrats on a successful launch. Really glad to hear everything survived. Are you planning any more powerful launches?

Yes! I picked up a K535 from Wildman at the launch, going to fly it on that next chance I get.