Re: Re: Mylar balloons

From: Brett Sanborn <brett.d.sanborn_at_gmail.com>
Date: Mon, 5 May 2014 16:27:31 -0400

Is 50 grams too light for one of these balloons then? Should we be worried
about reduced durability at half the weight (assuming thinner material), or
do we just think his estimate is a little low? Harlan's bridle can't weigh
45 grams.

Brett


On Mon, May 5, 2014 at 4:22 PM, <john_kagan_at_hotmail.com> wrote:

>
>
> I spoke with Dan and got some more info.
>
> - A 36" 4-gore ball will be the same price as a 48" ball. These will be
> hand-made, so the majority of the cost is in the labor. If we want to
> order 10,000 of them, we can start talking about tooling :)
>
> - Harlan's balloon weighs about 90gm with the harness, some tape patches,
> self-sealing valve, etc. Dan estimates a 36" balloon will be around 50gm.
> So we are good on weight
>
> - Dan says the balloon should lose about .24% - .5% per day, which means
> basically nothing. It should last a 5 day contest with no problems.
>
> - We have the option of a self-sealing valve (like what the flat party
> store balloons have) or a 1/2" spout. Dan recommends the spout because it
> is much easier to deflate. He says the spout will hold helium fine. The
> edge tapes over to seal.
>
> - He can add some tabs with packing tape reinforcement as attachment points
>
> - About 3-week lead time (emphasis on the "about". They are heading to
> the Knoll R/C event soon, and have other obligations to schedule around,
> too. They have one guy who knows how to do the hand-made process.)
>
> Dan was a little surprised that we were willing to pay that much for a
> hand-made balloon. He asked if we had tried the large balloons from the
> party stores or clusters of smaller balloons. I told him those options
> don't work for us.
>
> He also told me about an Indoor meet he went to. They had both R/C and
> Rubber FF. He wanted to fly both timeslots, so he added a rubber powered
> flapping mechanism for one of his blimps. Nice!
>
>
> ---In Indoor_Construction_at_yahoogroups.com, <frash_at_...> wrote :
>
> I don't steer via helium balloon and am unlikely to try to second guess
> Ray Harlan. He may use 8 gores to get a smooth shape. One can make a
> lifting balloon of many shapes from only two gores but the external
> heat-sealed seams may cut or entangle your F1D. Turning the envelope
> inside-out will not be trivial.
>
> It is worth contacting the RC toy blimp folks and seeing what they can
> offer. Toy RC blimps might be less expensive but lower quality than Ray's
> specialty balloon.
>
> Some "Mylar" blimps are (or at least were) made from 2 gores of heat
> sealed polypropylene sheet. One supplier for this polypropylene was in
> Italy but I do not have the contact information and this was in 2000. The
> outside was printed but whether the inside was treated to permit heat
> sealing is unknown to me.
>
> After retiring from the local chemical company (Eastman Chemical, 33+
> years), I worked a little for a local, now-defunct start-up RC toy blimp
> company. I calculated and measured lift, tested motors, props, batteries,
> built prototypes, test flew competitors' toys, and generally played in the
> lab. <Grin> I was not an investor and our business plan, quality, finances,
> and execution were weak. This start-up lasted about a year.
>
> The sealing iron that I used a few times was a soldering iron with a
> rotating cylindrical tip (a router bearing).
>
> Fred Rash
>
> On 5/1/2014 7:05 PM, leop_at_... wrote:
>
>
>
> My understanding is that Ray Harlan's balloons are heat sealed. I cannot
> say that they have no glued seams at all.
>
> By the way, the Harlan Mylar 35" balloon is made from 8 gores.
>
> LeoP
>
>
>
>
Received on Mon May 05 2014 - 13:27:32 CEST

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