[roc-chat] Re: Archetype line cutter
- From: Jeff Gortatowsky <indanapt@xxxxxxxxx>
- To: "roc-chat@xxxxxxxxxxxxx" <roc-chat@xxxxxxxxxxxxx>
- Date: Thu, 27 Dec 2012 21:37:50 -0800 (PST)
Interesting that the folks on TRF are encouraging me to build my Formula 98 as
a traditional DD and not a nose cone based DD using the cable cutter (motor
ejects the laundry, the cable cutter lets it loose). I love those guys, but I
think I'll not do so.
Using PEM nuts and screws I can build the Formula 98 with a straight through
tube (literally screwing together the fin can and the payload sections using
the supplied coupler that would normally be the altimeter bay). I can mount the
altimeter in the nose coupler and have a single (or dual wires) going to one
(or two for redundancy) cutters. The motor does the apogee honors. The cutters
the low alt. I don't give a hoot that the screws might stick out a
little...ever see a REAL rocket... smooth they ain't. ;)
If that makes any sense... :)
And nothing stops me from using the supplied bulkheads and some all-thread in
the future and making the central coupler a tradition altimeter bay. I'm with
you. I like the cutters.
---------------------------------------
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: Ed Holyoke <bicyclop@xxxxxxxxxxx>
To: roc-chat@xxxxxxxxxxxxx
Sent: Thursday, December 27, 2012 8:23 PM
Subject: [roc-chat] Re: Archetype line cutter
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 Rick
>
> I 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] 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=Dux4M77ZoxQ
>
>We 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
>Subject: [roc-chat] Re: Small DD
altimeters...
>To: roc-chat@xxxxxxxxxxxxx
>The instructions to the Defy Gravity Tether have a rough picture of a burrito
>style wrap.
>http://www.defyg.com/rapid.pdf
>I'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>
>To: 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 <ENHolmberg@xxxxxxx> wrote:
>
>From: ENHolmberg@xxxxxxx <ENHolmberg@xxxxxxx>
>Subject: [roc-chat] Re:
Small DD altimeters...
>To: roc-chat@xxxxxxxxxxxxx
>Date: Wednesday, December
26, 2012, 8:04 AM
>In a message dated 12/25/2012 7:27:30 P.M. Pacific Standard Time,
>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?
>
>
>
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