Loading ...
Sorry, an error occurred while loading the content.

14496Re: [GPSL] Parachute positioning and balloon interference

Expand Messages
  • Alan Adamson
    Aug 12, 2014
      Mike,


      I've been talking with the other Mike (who originated the question).


      Is there any relationship or dimensional concerns that need to be taken
      into account. For a really light payload, it might be that I can 3d
      print something to trial


      - https://dl.dropboxusercontent.com/u/6730484/jaws.png was just a whack
      at a basic design that I threw together this afternoon after looking at
      your web information.


      E.g. is there an amount of spring tension that you need, etc.?


      Alan


      On 8/12/2014 5:43 PM, Mike Manes mrmanes@... [GPSL] wrote:
      > If the latex shards are interfering with the 'chute's performance,
      > that will be evident in strings of latex fouling the shroud lines
      > and/or canopy on recovery. The quantity of latex remaining attached
      > to the neck varies all over the map.
      >
      > Prior to implementing the fast releases, EOSS would bring home
      > anything from just the neck all the way up to 6 lb of shards
      > from a 3000 gm (6.6 lb) balloon.
      >
      > The fast releases have definitely sent PBC to charm school for us!
      >
      > 73 de Mike W5VSI
      >
      > On 8/12/14 12:20, 'Barry Sloan' bs@... [GPSL] wrote:
      > >
      > >
      > > First thing I’m wondering is whether your chute has an air dump opening
      > > at the top. If it doesn’t I’m guessing that the chute is often swinging
      > > side to side to allow the trapped air to escape with such a light
      > > payload attached so close to the chute and attaching the payload further
      > > away may make it harder for the chute to do this. I don’t see the
      > > remains of the balloon flying around and tugging and/or hitting the
      > > chute affecting it much, but if the remains weigh as much, or much more,
      > > than your light payload they would certain increase the descent speed
      > > over what the speed with just the payload would be.
      > >
      > > Barry VE6SBS
      > >
      > > *From:*GPSL@yahoogroups.com [mailto:GPSL@yahoogroups.com] *On Behalf Of
      > > *Michael Hojnowski kd2eat@... [GPSL]
      > > *Sent:* Tuesday, August 12, 2014 11:55 AM
      > > *To:* GPSL Balloon Reflector
      > > *Subject:* [GPSL] Parachute positioning and balloon interference
      > >
      > > Hi Gang,
      > >
      > > I've done several launches where we observed the descent rate to be MUCH
      > > higher than the projections based on various parachute calculators.
      > > I've grown suspicious that the parachute's function is being severely
      > > hampered by the remains of the balloon flying around and tugging and/or
      > > hitting the chute on the way down.
      > >
      > > I've seen some mechanical means used to release the balloon when lift is
      > > removed, but we're flying very light (100g) payloads. I haven't seen
      > > anything that would work with something so light.
      > >
      > > Presently we're flying with the payload directly attached to the chute
      > > with short cords (maybe 18"), and the parachute then connected to the
      > > balloon by a much longer 10' long cord.
      > >
      > > Any thoughts or suggestions would be appreciated!
      > > Mike / KD2EAT
      > >
      > >
      > >
      > >
      >
      >
    • Show all 8 messages in this topic