Yeah, Jeff I got to thinking about why I need more BP than they say to use and it occurs to me that pressure blowing out the oversize e-match hole might just be the reason. If you look at his video, the match pretty much stops the hole up unlike with the Q2s. Mine always blow the match clear so you know there's gotta be some lost pressure. I didn't know about the smaller diameter drilled screws, but I think it sounds good. It'll probably still blow the match out, but more of the pressure will be used to move the piston. Maybe I'll make a few and do some experiments.
I like these line cutters. They are much more reliable than the ones I used to make and always, always, always test new techniques and equipment on the bench before you count on them to save your rocket.
Pax, Ed On 12/27/2012 10:25 AM, Jeff Gortatowsky wrote:
Think it was Ed that turned me on to the device a few months ago. Guess I'll just echo what he said. :) I pass my protector through the shock cord not the chute lines. I use a tad more BP (like 50% more - because Ed told me to!). I retain the cutter with kevlar string attached to the shock cord. I don't rely on the e-match to retain it.Regard Q2G2, I've used them on two flights and they worked fine. The other flight was an old BlackSky Hi-Ri. The seller now has a screw cap with a smaller hole specifically for the Q2G2s as before the bigger hole allowed BP to leak out around the wire. (You can read about varying e-match wire widths and what to do about it on the seller's web site). Before I got Q2G2 caps, I used the caps with the bigger screws by literally fattening up the Q2G2 wires with a strand of CAT5 wire spiraled wound around it for an inch or so and a tiny piece of scotch tape..I've bought extra caps and have two or three always prepped as Ed mentioned, with a Q2G2 and hot melt glue dabbed on the cap screw to seal it.Web site: http://lkal32.blogspot.com/p/archetype-rocketry-products.html ---------------------------------------Jeff Gortatowsky, Redondo Beach, CA | Twitter: JeffGortatowsky | Yahoo: indanapt "(Scientific) Skepticism is not a set of beliefs, it is a set of methods for asking questions about reality." -- Doctor Steven Novella------------------------------------------------------------------------ *From:* Jack Garibaldi <jackgaribaldi@xxxxxxx> *To:* roc-chat@xxxxxxxxxxxxx *Sent:* Thursday, December 27, 2012 8:35 AM *Subject:* [roc-chat] Re: Archetype line cutter Thanks, I figured there was some trial tricks Jack G*From:*roc-chat-bounce@xxxxxxxxxxxxx [mailto:roc-chat-bounce@xxxxxxxxxxxxx] *On Behalf Of *Ed Holyoke*Sent:* Thursday, December 27, 2012 8:21 AM *To:* roc-chat@xxxxxxxxxxxxx *Subject:* [roc-chat] Re: Archetype line cutter Howdy Jack,It's a really small space that the match and powder co-exist in. It would be hard to imagine the BP not being ignited by the match. That said, I have increased my BP loading slightly as I had a couple of test cuts fail to shear the zip tie fully. Also using Q2G2s, the hole through the screw head is too large to seal the BP in. I fill the recess in the head with hot melt glue. That seals it up nicely, The match and hot melt will blow right out so the retainer cord becomes primary if you want to get the line cutter back. I attach that to a quick link on the shock cord.I think the most important point about the orientation of the cutter is that the wires to the match must not be stressed. I pass them under the zip tie, (along with the shock cord to the booster) and leave plenty of slack so that the burrito isn't being dangled from the wire.One more minor point - I retain the parachute protector that forms the burrito to the shock cord and attach the chute separately. I want the chute to spring completely clear of everything around it and deploy untangled. If you pass the shroud lines through the button hole in the protector as shown in the video, you may end up with it riding up the shroud lines and preventing full opening. I've had that happen before. If you have too much chute on a windy day, maybe that would be a good thing. ;-)Pax, Ed Holyoke On 12/27/2012 7:47 AM, Jack Garibaldi wrote: Hey RickI am curious on that video, it appears that the E-match is say 1” from the top and the Black powder is all the way down say on top of that piston and is free to float around so orientation must be important so there is some BP on the e-match?Jack G*From:*roc-chat-bounce@xxxxxxxxxxxxx <mailto:roc-chat-bounce@xxxxxxxxxxxxx> [mailto:roc-chat-bounce@xxxxxxxxxxxxx] *On Behalf Of *Rick Maschek*Sent:* Wednesday, December 26, 2012 11:52 PM *To:* ROC-Chat *Subject:* [roc-chat] Re: Archetype line cutter If a picture is worth a thousand words, how many is a video or two worth? http://www.youtube.com/watch?v=qjIDk5Z6WIA http://www.youtube.com/watch?v=Dux4M77ZoxQWe designed a custom dual drogue deployment in the 3.5" MiniSShot rocket to use very little if any black powder. Then the main chute deployment uses just an ematch for its release. A pin secures the main from being pulled out by the drogue and the ematch simply pushes the pin out allowing the drogue to pull out the main out of the same bay. Three chutes with just 0.05g of black powder though everything dependent on the drogue separation successfully deploying.Rick ------------------------------------------------------------------------ Date: Wed, 26 Dec 2012 15:09:42 -0800 From: indanapt@xxxxxxxxx <mailto:indanapt@xxxxxxxxx> Subject: [roc-chat] Re: Small DD altimeters... To: roc-chat@xxxxxxxxxxxxx <mailto:roc-chat@xxxxxxxxxxxxx>The instructions to the Defy Gravity Tether have a rough picture of a burrito style wrap.http://www.defyg.com/rapid.pdfI've used the Archetype Cable Cutter three times now and always use this 'burrito' method of wrapping. You wrap the chute in the protector as if you were making a burrito. One end, the bottom, of the protector is folded under, then rolled up with the chute attachment sticking out the top. You wrap the chute/protector in a ty-wrap and run it through a hole in the cutter and cinch it tight. Another side benny is you can cinch it really tight so it fits into a tube easier. You want the whole thing to 'pop' open when the ty-wrap is cut. With a cable cutter IMO, you lose half the complexity and time of Dual Deployment. I motor eject the bound up chute and at 500' the cable is cut and the main unfurls. The Defy Gravity Tether and Tether Descender work about the same. The Archetype cutter is very small and uses an internal piston to cut a thin ty-wrap that is keeping the chute bound up. (Just use .2gm of BP instead of .1gm) :) Of course motor ejection at apogee still has it's issues. And if the charge does go off but the rocket did not split apart, well, its a lake stake. Nothing however stops you from using two charges in the same compartment, one to fling out the cinched laundry and the other to unravel it.---------------------------------------Jeff Gortatowsky, Redondo Beach, CA | Twitter: JeffGortatowsky | Yahoo: indanapt "(Scientific) Skepticism is not a set of beliefs, it is a set of methods for asking questions about reality." -- Doctor Steven Novella------------------------------------------------------------------------*From:*Mike Riss <rockt_dude@xxxxxxxxxxxxx <mailto:rockt_dude@xxxxxxxxxxxxx>>*To:* roc-chat@xxxxxxxxxxxxx <mailto:roc-chat@xxxxxxxxxxxxx> *Sent:* Wednesday, December 26, 2012 2:03 PM *Subject:* [roc-chat] Re: Small DD altimeters..."*/burrito style/*" is when a parachute is wrapped in a 'chute protector much like how a tortilla is wrapped around a burrito.Mike--- On *Wed, 12/26/12, ENHolmberg@xxxxxxx <mailto:ENHolmberg@xxxxxxx> /<ENHolmberg@xxxxxxx <mailto:ENHolmberg@xxxxxxx>>/* wrote:From: ENHolmberg@xxxxxxx <mailto:ENHolmberg@xxxxxxx> <ENHolmberg@xxxxxxx <mailto:ENHolmberg@xxxxxxx>>Subject: [roc-chat] Re: Small DD altimeters... To: roc-chat@xxxxxxxxxxxxx <mailto:roc-chat@xxxxxxxxxxxxx> Date: Wednesday, December 26, 2012, 8:04 AMIn a message dated 12/25/2012 7:27:30 P.M. Pacific Standard Time, bicyclop@xxxxxxxxxxx <mailto:bicyclop@xxxxxxxxxxx> writes:Howdy Jeff, Most trackers do operate on ham frequencies. It's easy to get a technician license. The Raven altimeter uses a 110mAhr battery and fires Q2G2 matches reliably. They're going to draw less than 2 amps at 4 volts. I flew my red Formula 54 on it, /*burrito style*/, on Saturday. I had a BigRedBee beacon in it and used my homemade yagi to DF it about two miles away. Those winds aloft were vicious. Josh flew his extended Formula 75 with one and with a BigRedBeeGPS. He has a Yeasu VX-8GR with built in GPS and APRS packet decoding and walked straight to it. Having a handi-talkie to call for help isn't a bad idea when you're walking around out in the desert. Ed, What is */burrito style?/*
