14496Re: [GPSL] Parachute positioning and balloon interference
- Aug 12, 2014Mike,
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.?
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
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