I'd suggest you get an answer on this from the prefect that will be doing the cert of your flight... but I'd keep it over 1,000 feet for the main and apogee for the drogue... no sense in opening it so close to the ground. anyway, my 2 cents 😉

How small is the parachute, and how are you packing it? It all depends... 😯 What Brent said, L1 is fine, but the L2 is somewhat iffy. I have a Thunderbolt 38 that I'm going to fly with a J350 some time this year, after an I357 just to make sure my modifications are stable. Do the L1, and see what develops, one step and letter of the alphabet at a time. You'll nail an L2 with a GLR Vertical Assault. Definitely set your main higher than 300 foot, unless you wanna dig it outa the ground. 😉

Actually The prefect or any TAP or TRA BOD member can perform both the L1 and L2 certs under Tripoli.

If NAR then for your L1 cert you would need either 2 L1 flyers to sign off or 1 L2/L3 to sign off and for your L2 you would need 2 L2 flyers to sign off or 1 L3 to sign off.

Adrian. Are you planning on doing this via TRA or NAR?

Let me know if I can help as I can do both NAR and TRA certs. (I am a TAP/L3 flyer) Also the main reason I keep my dual affiliation.

If it were me I would recommend to deploy no lower then say 400 to 1000 ft. I would probably lean more towards 800 - 1000ft area. I like most of my stuff to deploy a hair higher and see them to get a good bead on them, as well as give the recovery ample time to get out and get inflated. The larger the rocket the higher I would like to open the main. Like for my L3 rocket (full Throttle- 15' tall 70lbs) I open my main between 1000 and 1500.

Conway

What Conway said. Better be safe than sorry! 8)

Adrian. Are you planning on doing this via TRA or NAR?

TRA. Thanks, Conway. If you can be there for the March flight I would appreciate your help.

For the Thuderbolt I think I'll do the main at 700 feet. I want to be close enough to it to see what happens.

When I test out my av bay with the Blue Ninja it will be on a small-ish field, so I'll have a motor small enough that it would have a hard time getting above 600 feet. It will have a 24 inch nylon chute that should inflate pretty quickly and slow the rocket down quickly, so hopefully a lower altitude should be o.k.

For the March flight, I'll be prepared to take the test and fly a J, in case the H flight goes well enough that all systems are go for L2. But if the rocket's flight isn't clean and straight or something didn't go right with the recovery, I'll leave L2 for another day after I get the kinks worked out at L1.

Here is my new avionics sled inside the coupler of the Blue Ninja.

And a closeup:

In the picture is the deployment charge battery, the Parrot with its own battery, and an arming switch that I will be able to activate externally. The Parrot is getting charged via USB. What you see in the picture is 31.8 grams. Not shown is the BigRedBee transmitter that will mounted on the back side and be powered by the pyro battery.

I'll be able to use this sled in the Blue Ninja and in my GLR Thunderbolt 38.

Any suggestions for the deployment altitude? For my Blue Ninja tests, I'll probably use 300 feet, but a lot higher seems more common. How long does it take for a small parachute to open?

it really depends on decent rate, over all altitude and then size of rocket.

if you are going for a lower altitude then you will want to make sure you can easily track the entire flight. I find it easier to find the rocket in the sky if I have a little more time to spot it. I personally would use 500 ft to 800ft for your L1 and L2but you could go to 1000 if you wanting a little more time to spot it.

A small chute will open differently depending on how you pack it. If you use the method that puts the shroud lines in the chute and then fold it up and roll it up, it will open fast but if you rap your lines around the chute it is a lot slower. lots of ways to fold your chute and that is the biggest factor. I would recommend the PML version to start with, it works very well.

https://blastzone.com/pml/parachutepacking.asp

I have always used my own version of this, it is always a fast opening chute.

8) I don't think that you can damage a Thunderbolt if it comes apart as planed at the top. It can easily take a drop under droge. (I know) Just remembre that the space is tight, use a small soft chute. Your main can come out at either 700 or 1000, either way the walk will not be far. I don't think mine is more than 24". It will land on the fincan and will be good to go. The problem I see is L2, J motor and that 38 'Bolt will be GONE! Best wait for the North Site! 8)

A small chute will open differently depending on how you pack it. If you use the method that puts the shroud lines in the chute and then fold it up and roll it up, it will open fast but if you rap your lines around the chute it is a lot slower. lots of ways to fold your chute and that is the biggest factor. I would recommend the PML version to start with, it works very well.

https://blastzone.com/pml/parachutepacking.asp

I have always used my own version of this, it is always a fast opening chute.

Thanks, this is my plan for packing the chute also. I think I'll go for a 600 ft opening.

I don't think that you can damage a Thunderbolt if it comes apart as planed at the top. It can easily take a drop under droge. (I know) Just remembre that the space is tight, use a small soft chute. Your main can come out at either 700 or 1000, either way the walk will not be far. I don't think mine is more than 24". It will land on the fincan and will be good to go. The problem I see is L2, J motor and that 38 'Bolt will be GONE! Best wait for the North Site!

I was planning to do the apogee deployment using the motor charge, drogueless. When you were talking about a dropping under drogue, was that with a drogue chute (and what size) or was it just with the sections separated? I have a new 36" spherachute for the main. The 36" chute measurement, it turns out, is measured as half of the circumference, so the diameter is about 23." Hopefully that will be enough.

I simmed the Cesaroni pro-38 J285, and it went to about 9kft, so it should be o.k. as far as the waiver goes. I have the BeeLine transmitter in the av-bay, so going out of sight should be o.k, too. I'm putting the 36" tube in the back and the 18" tube in the front, so I can put some long motors in there (Eventually, a 28" long hybrid). The back end has a Slimline motor retainer. Tim, what will you have available for smallish Js on Saturday, in case my level-1 flight goes o.k.?

Adrian, The chute should be 36" across, you may have a mislabled one. No worrys, I will have a 36 with me, we can swap it out. I packed my Bolt to tight a couple of times and it separated but did not deploy. THUNK But it was just fine. (twice) No one ever said I was real sharp, but I did finaly get it and put in a smaller chute, loosely. Your setup sounds better than mine, so you should be good to go. I will have the Motors with me, bring your glasses! Tim 8)

Adrian, The chute should be 36" across, you may have a mislabled one. No worrys, I will have a 36 with me, we can swap it out.

Actually, after some deployment tests this evening, the chute that I have is the biggest that will fit anyway, so hopefully it will be enough. By the way, I've been having success with Pyrodex by potting Estes igniters into 1/4" cardboard launch lug tubes using 5 minute epoxy. Here are two 1/2" ones, one 3/4", and one 1." The 1/2" ones are good for my Blue Ninja, and the 1" one worked well for the Thunderbolt.

Interesting.
Been trying to master the art of ematches the last few nights, with disapointing results. Will a 9 volt fire an estas igniter. I guess I could try it. 🙄

You could try, but it would probably require a long "on" time, possibly latched. Most altimeters just give a blip of current to pop an ematch.

Everyone post results from any experiments! 8)

Ken

Yes, a 9V battery will fire an Estes ignitor. That's actually how I've been doing my ground tests recently, since I seem to have misplaced my Estes launch controller. I didn't notice any delay; they seemed to go off pretty much as soon as I made contact. The Parrot altimeter latches the firing circuit on for 1 second, and I seem to recall that at least some other altimeters use 1 second also. I'd check your user manual or better yet, do a test with a DVM that beeps for continuity to be sure.

As for results of the above method so far, they are:

1/2" charge in a Blue Ninja with a piston and a sealed bulkhead: perfect
1/2" charge in the same Blue Ninja with a hole in the bulkhead and another in the piston: Partial ejection (lesson learned: Pay attention to pressure leaks)
3/4" charge in a Thunderbolt 38: partial ejection
1" long charge in a Thunderbolt 38: adequate ejection, but a little wimpy

1.25" long charge in a Thunderbolt 38: Test tonight

The construction method seems like it should be self-explanatory from the pictures, but in case it's not:

1. Cut your tubes in lengths appropriate for your rocket(s) based on ground tests
2. Carefully bend up the tips of the ignitors so that the ignitor head will be in the middle of the tube while the rest of the ignitor is laying flat
3. Mix up some 5-minute Epoxy and glop some onto some plastic or waxed paper. Set the ignitors into the epoxy, making sure that the leads are completely embedded and the head stays dry
4. Put the cardboard tubes over the ignitor heads, doing a little twist to make sure the epoxy adheres to the sides of the tubes all the way around. Wait for the epoxy to cure.
5. Fill up the tubes with Pyrodex or BP. Tamp down gently so the powder leaves the top edge exposed all the way around.
6. Mix up another batch of epoxy and cover the ends of the tubes, making sure that the epoxy adheres to the sides of the tube all the way around the top.

Time to make a batch of 6 charges: 10 minutes + waiting for cure + 5 minutes

Cost: $5.00 for 6 ignitors + $0.10 for powder + ~$1 Epoxy