xvwdvw01

I have ordered a blimp from Dragonflyer and am looking at various camera systems to attach to it. I was most worried about vid quality and weight, I believe it can carry up to 3oz at sea level, not sure at my alt of 5300' here in Reno. After reading through some of the posts here I am also concerned about penetration through walls. I would like to cruise it around here at work from my desk but this building has metal studs that the sheet-rock hangs on. Home is a small 1 story with regular frame const so I think anything that will work in the office will work better at home. I have been told that 802.11x networking stuff has trouble in these buildings but haven’t tried it myself yet.
I like the spider might stuff from Blackwidow and also some of the smaller 5v systems he sells. The spider should be plenty light but I worry about power and with the bigger ones I don't know what the combined weight of all the components will be. Plantraco has a ready to go system but I am not wild about the cmos cam or being stuck to a manual tune tv for viewing. Although the little tv might be the easiest way to view as I fly without lugging a real tv around.
I also have a GWS Tigermoth that I would like to stick a camera on some time but I assume it can carry the same or a little more than the blimp if I keep the motor batt light.
Thanks,
Max

jjjones

I have a similar blimp, and it's loads of fun! However, the payload is almost zero, and the blimp's buoyancy is amazingly sensitive to things like air temperature. So I'd strongly suggest you play and experiment with the blimp for a while before you buy a camera. One tip- get it filled at a store. Most supermarkets seem to have a helium tank for the ballons they sell, and it's been my experience that they're happy to fill my blimp. I've never paid more than $2. The Balloon Time brand helium tanks available at Wal Mart and BJ's are handy for topping off a flacid zeppelin, but are too expensive to use to for a complete fill. I think BJs sells a larger tank than Wal mart, for the same price- $20. I've found that after about 2 weeks, the blimp needs a top-up on helium to stay in the air, although it starts looking saggy before that. The manual on mine suggests just blowing air in to puff it back up- DON"T DO IT! That thing needs all the helium it can get, and diluting it with air will keep it on the ground.

smokingcrater

you probably can also buy bulk helium from your local welding supply place, MUCH cheaper than anywhere else...

yb2normal

Sorry for the OT question, but what is helium used for in welding?

Or are you referring to a supplier of gasses in general.

Thanks!
Bill

jjjones

I looked into that a little, and while the helium itself is cheap in bulk, buying or renting the big tank, and especially the valve mechanism that sits on the tank, is prohibitively expensive, at least for a little toy blimp.

xvwdvw01

Thanks for the info guys. JJ, you hit it right on the head with the performance of the blimp. What Alt are you at? At first it would not get off the ground even with so much pressure most of the wrinkles were gone. I removed the batt door and then it would fly but after an hour or so I was adding ballast even after putting the door back on. It has been two days now and last night I put enough weight on it to make it sink pretty good in case I lost it on the way to the car. As soon as I got it out in the 25 degree air it was trying to float like crazy, then after being in the cold car for 20 min. I had to remove almost all the ballast to get it to hover in the 62 degree house again. I will bring it to work and get it warmed up to room temp, get it ballasted just right, then weigh the ballast on our mail scale to see what the "payload" is. I don't think it is even an ounce so far though. I am using helium from one of those "party kit" helium tanks and was told to try filling from a welding shop or ballon store not just to save $'s but because the helium I got in my tank might be diluted for safety reasons.
It is a blast to play with in the living room, I just need a bigger house! Also, even if I can't get the blimp to lift a camera I could still use it with my Tiger Moth, so I will probably give it a try.

billmi

It's used to displace air in some types of arc-welding. Arc welding with many metals will cause the metal to boil and pop if it's exposed to air during the weld, due to rapid oxidation of the metal. The He2 displaces the oxygen away from the arc. In typical steel arc welding CO2 is used for this, I think helium is primarily used in aluminum welding (though why the different gasses, I don't know.)

jjjones

I'm near sea level. Glad you're having fun with it. It's almost a science lesson, seeing how the buoyancy changes with temperature- In a heated 2 story house, where I couldn't tell any difference at all in temp, the blimp would slowly sink on the 2nd floor, but float to the ceiling on the 1st! Trying to fly it down the stairs was nearly impossible, as it seemed to gain lift as it descended. And as it got near one small, single-pane window on the first floor, it would drop dramatically in the cold area.