98mm min dia high altitude deployment

[OverTheTop]

If you use small diameter canons you can machine the top of the well to accept centrifuge vial caps. Just fill with eMatch,BP, wadding and clip the cap in .



https://forum.ausrocketry.com/viewtopic.php?f=6&t=3997&start=15

For larger wells you can machine threads that accept other caps, in this case lemonade bottle caps.

 

[plugger]

Plugger, Thanks for adding info to this thread! In one of my posts above I made reference to "I came up with (or so I though I did)" comment. Now you show me some fancy metal ejection cannons...from down under. (seems like good/great ideas, concepts and techniques take time to travel up and around to this side of the planet.

So can I say I came up with the idea for DCC's (Disposable Charge Cannons) [ala Aerotech DMS motors] atleast?

Yep..those N5800's ate a bunch of rockets!

Tony

My pleasure Tony! I'm a big fan of sharing info when it comes to rocketry, both successes and failures. Your video series on youtube have been a HUGE help to me in the past and even up to today (eg your bevelling video). And yes, down here we've got a small but incredibly active community, as well as access to aluminum like our freedom unit using counterparts (granted it's pronounced differently down here!).

As mentioned upthread I'm just following in Mike and Nic's footsteps. First time I saw a charge cannon was 2012 in Mike's "Don't Debate This" N5800 MD rocket. Here's a pic.

While there are some benefits to that design (like having your BP gasses exit the cannon above your parachute) I figured I'd try and collapse the unit fully within my AV bay to save on space. Hence my move to recessed cannons.

All that said I'm fairly certain you and Jim were doing high alt surgical tube deployment tests long before this! Given that in my mind you're the one who started the whole thing. And if I'm being honest I vaguely recall seeing a recessed charge cannon in a 54mm MD rocket Charlie from CCR flew in 2013 at Balls. So, yea, I'm really just following on from others.

Thanks for the response.

drew

 

[plugger]

Plugger, did you turn your cannons on a lathe yourself, or is that something you bought as-is? I really like the recessed cannon concept to save space.

I definitely didn't turn them myself. One of the guys in our club has access to people who work on lathes through work and was able to get them done up for me. He didn't want to charge me for them but I've got other ideas. We've got a club launch on Saturday and I'll be handing him a RATTworks J160 as a thank you. Fingers crossed that will keep the charge cannon gravy train moving!

 

[tfish]

I was able to do the 'main' ground tests. The only out of the ordinary part is that I've been using latex balloons for my non high altitude deployment charges. They've been working well. I've had as many as 6 charges in a 3" cardboard rocket (used to test up to 3 altimeters at a time) without any issues. Primarily "sympthyatic ignition" of another deployment charge. I've had it happen a coupe of times using thin vinyl glove fingers. I've done about 20 flights using "water balloons" with up to 1.5 grams in them. I do fold them back over themselves which gives them 2 layers of latex.

The charges below (which were used in the below videos) are in bigger balloons and get folded back over themselves 3 times...I just tie them off with sewing thread.


Spent...




Low Altitude "Main" ground tests 98mm 175 cu/in

1.5 gram



2 grams


Tony

 

[tfish]

I found a pretty cool clear coat. I git tired of the Rustoleum "what's it going to do this time' routine The clear coat is a 2 part automotive clear in a single spray can.. $29

Color coat: True Value Premiumdecor Fluorescent yellow....



2 coats 2K Clear Glamour


Tony

 

[Ez2cDave]

The clear coat is a 2 part automotive clear in a single spray can.. $29

Tony

I just "crunched the numbers" about using that clear on my upcoming L3 and got "premature sticker shock" . . . About 3600 sq. in. of surface area X 2 coats = 7200 sq. in. = 49 sq.ft.

How much "area coverage" does one can of that clear provide ?

Dave F.