Binder Design Excel Dual Deploy L1 Cert Build

[conwayte]

I'll be starting work on the electronics soon. I have a Missile Works RRC2+ in hand and an Eggtimer Quark on the way. The Quark should keep me busy for a few nights. I hadn't planned on doing redundant DD but the avbay is huge and the RRC2 looks awfully lonely by itself, so I figured what the heck.

 

[conwayte]

Well, I was able to get 3 rounds of ground testing in between rain showers. I couldn't find any 4fg black powder and I couldn't pull the trigger on ordering online with the extra fees. The local sporting goods store carries Triple 7 in a 3fg so I bought some of that. After reading through as many threads on bp substitutes as I could find, I started with 1.5 gms of Triple 7 (that is the calculated amount of bp so I thought it would be a good starting point). After tamping it down with wadding and taping over with two tight pieces of electrical tape across the top and then a band around to secure, I was quite pleased with the result. The 1.5 gms put the payload bay/nose section out about 15 of the 25 ft of harness. For the next two tests I went right up to 2 gms and got full extension of the harness with a bit of a tug on the booster.
I haven't done any testing of the main section yet, I'm still figuring out how I want to do my retention. I have a bunch of 2-56 shear pins but for today's round I just used 3 strips of 1/2" scotch tape between the booster and the avbay and it sheared nicely. Maybe I'll just use that--seems simple and effective. I'd be curious to hear other thoughts. I plan on using removable rivets to secure the avbay to the payload bay and pop the main out through the nose.
I have 17 Wildman lighters left and a lot of Triple 7 so I'm going to continue to test until I'm satisfied that I have a predictable and repeatable configuration. I apologize that I don't have any pics/video of this round--I didn't have enough hands to run my shop-vac and take video at the same time. I will definitely get something posted after the next round.
My plan is to try for my Level 1 certification at the May 13th launch with Tripoli MN. They've been very helpful via email and I'm looking forward to meeting some folks!

Electronics set up so far; I'm wiring the ematch directly to the altimeter at this point (the orange wire going off to the left is the clipped section of ematch--I left my little screwdriver in the basement):

Charge well:

 

[Coop]

Watching with interest. I have one of these in the build pile--if I had a brain I would have thrown it in the car to bring to work with me this weekend.


Later!

--Coop

 

[conwayte]

I decided to sneak in one more test today and get a video clip. I direct-fired this one rather than use the shop vac to pull a vacuum--a lot less monkeying around. You'll notice this one didn't get quite to the end of the harness. At first I couldn't understand why but then I noticed that it kicked out the shop rag that I was using to plug the motor tube. On my earlier tests I put some duct tape over the motor tube as well as the shop rag--forgot the duct tape on this one. I'm guessing that was the difference but I'll continue testing since this wasn't an expected result. (Plus, it's kind of fun making things go bang)

[video]https://youtu.be/5i_jxJNgVBo[/video]

 

[conwayte]

Watching with interest. I have one of these in the build pile--if I had a brain I would have thrown it in the car to bring to work with me this weekend.


Later!

--Coop

When I saw the link in your signature line, I thought, "wait, there's a rocketry-related website that I haven't seen yet!" When I looked at your news section, I realized you've just recently gone live--congratulations-very cool! Looks like you have some cool and well-built parachutes. Love those old sewing machines!
Tim

 

[Coop]

I decided to sneak in one more test today and get a video clip. I direct-fired this one rather than use the shop vac to pull a vacuum--a lot less monkeying around. You'll notice this one didn't get quite to the end of the harness. At first I couldn't understand why but then I noticed that it kicked out the shop rag that I was using to plug the motor tube. On my earlier tests I put some duct tape over the motor tube as well as the shop rag--forgot the duct tape on this one. I'm guessing that was the difference but I'll continue testing since this wasn't an expected result. (Plus, it's kind of fun making things go bang)

[video]https://youtu.be/5i_jxJNgVBo[/video]

I mostly fly CTI reloads. Their 38mm nozzles, once spent and separated from the liner, typically screw right back into the casing from whence they came --so what I did was ran a pair of leads with alligator clips through an old nozzle and sealed the end with some garden-variety hot glue (or 5 min, on another; works equally well). Then for ground testing, I screw that into the 38 casing, run the leads to the charge, slide the motor/lead assembly in, secure with the attached retainer and let her rip. Can step up to 54 easily with an aeropack (or make a new one). I ran 38-54-75 for testing in Goblin (carefully balance the forward rings and it works), and there's no reason why you couldn't do this for 98 as well. I like using the 38 and adapters because the larger sizes don't screw directly to the case.

Later!

--Coop

 

[conwayte]

Well, I finally got to fly this rocket today and successfully obtained my L1 certification! Low and slow was the order of the day and I put it up to just shy of 1000' on an AT H219. The apogee deployment was fired off right on cue by the RRC2+ and the Jolly Logic Chute Release did its thing at 300'. The winds were pretty light so I didn't need to use the JLCR but it's too cool not to use it.
Thanks to the members of Tripoli MN for being so helpful! Thanks to Mike at Binder Design and Teddy at OneBadHawk for your help!


Here's a low-quality phone video. It was a little nerve-wracking, hence my commentary at apogee deploy and chute opening.

[video]https://youtu.be/Wnj9lMUgpko[/video]

With the certification pressure off, I flew my stretched Leviathan to right around 1800' on an AT H135.

 

[Binder Design]

Congrats! Thanks for choosing Binder Design!

 

[nmartin]

Congratulations!! That's a great looking field to fly at and a great day.

 

[mccordmw]

Yay! Congrats on your certification.

 

[RocketFeller]

Congratulations, looks like some beautiful spring weather!