Working on some new options with these, the foam resin is still a bit tricky . . . trying some paper clay material to cast them from - light and strong . . . lots of time to ponder these days . . .
Working on some new options with these, the foam resin is still a bit tricky . . . trying some paper clay material to cast them from - light and strong . . . lots of time to ponder these days . . .
When you get your manufacture method sorted Dave, you know you can always put me down for three more.
Rob.
"Courage is the art of being the only one who knows you're scared to death."
I would be interested as well, if there are any left...............
I laugh in the face of danger - then I hide until it goes away!
Dave I mean this in the most respectable way but you are insane. Those are fantastic and what you form for a base is great. Gives me an idea for some planes I have.
Last edited by BobP; 02-27-2017 at 13:30.
hi Dave
I would still be interested in about 4 when you get them sorted out
I know you will find a way to make those balloons.
Okay, I have a PM request log jam, so I am getting serious on these guys. Making them by 3D printing would run us over $15 each, I think we can do better . . . here is a glimpse of what is involved . . .
Not happy with the expanding foam castings - too much shrinkage and texture issues . . .
So I bit the bullet, took one of them and cut it into castable bits . . . mounted to a casting plate . . . built a dam box around them . . .
Volume calculations were made . . . box is sealed . . .
Water is poured into the mold box to capacity, poured off into a plastic mixing tub,
water level in the tub marked with a water proof marker . . .
wipe out the extra water, dry mold form . . .
Mixing tub weight is zeroed out on the digital scale . . .
The magic molding kit - latex liquid, hardener, mixing knife, instructions, scale . . . all you need to make the mold!
Vinyl mold liquid is poured into the mixing tub up to the line . . .
Weight of the vinyl must be found, hardener weight is 10% of mix . . .
Love the mad scientist aspects of this process!
Add the hardener and stir!
Once fully mixed, the light tan liquid is carefully poured over the mold plug to eliminate bubbles and air packets . . .
Fun!
Now we wait . . . tough part. I let things set overnight . . .
Stay tuned for part two . . .
Wow! that is a lot of work..........
Looks like Herr Baron Doktor von Clipperstein is up to his old tricks! It won't be long before we'll be able to join you in a chorus of "It's alive!"
Great watching your progress here, Dave!
All the best,
Matt
Dave, whatever works for you. There are enough people here that want to buy your stuff, no matter how it is produced. You are the man!
Run for your life - there are stupid people everywhere!
So we are closer . . . phase one of our journey is complete, we carefully remove our mold from the form . . .
Serious fans will ask, didn't you do this once before and just cast them from solid resin? And I will say yep, but they were too heavy, as you of course remember and took a lot of resin to cast, and I will say, " indeed."
The searching eye will see a missing bit . . .
One of the halves has been freed from its matrix and ravaged with a grinder to produce this strange new piece . . .
Which was forced into this mass of air dry clay . . . leaving a nice impression . . .
More science! Mold putty is groovy!
Equal masses of part A and part B
Squeezed and forced into our clay mold . . . twice . . .
First form is nestled into the main mold . . . its twin awaits its curing time . . .
A wooden bridge is fashioned and the twins attached to it, the method of my madness is beginning to emerge . . .
And here we have a ready mold for making HOLLOW blimps from resin! I really hope the elves are right about this . . . time to rest the fingers . . . back into the wax . . .
Fascinating to see what Dave can get up to when let loose!
Looks as if you have sussed this one out then Dave.
Well done that man.
Rob.
"Courage is the art of being the only one who knows you're scared to death."
Now to assemble them, paint base them, then we will know.
Amazing stuff here, Dave - the 'hollow' aspect is ingenious! Well done, indeed
Now this is what I call real therapy!
All the best,
Matt
Great work as usual Dave. Going hollow makes them lighter and saves on resiin so you can make more, a win-win.
Can only second what others have said. Great work as always.
Amazing!
Simply Amazing!
I laugh in the face of danger - then I hide until it goes away!
You're work is amazing. Great job.
Just picked up a new belt for my table top sander and some new masks so if the hands are willing tomorrow we sand!!!!
Very nice, surprised you did not suspend a foam core in the center of the mold to cut back on material use. Just put it on a thin rod that the mold would fit around.
Superb work Dave.
Run for your life - there are stupid people everywhere!
I wish I had your modelling skills Dave, what I do have is some research skills so for those who don't know, a brief description of how the Barrage Balloon worked.
The standard barrage balloon used throughout the war was designated the LZ (Low Zone). It was just over 62 feet long and 25 feet in diameter at its widest part and had a hydrogen capacity of 19,000 cubic feet. The LZ balloon was flown from a mobile winch and was designed for a maximum flying altitude of 5000 feet. The winch speed limited the raising and hauling down speed to about 400 fet per minute, which meant that the balloons required 11 minutes to reach 5000 feet from their close-hauled altitude of 500 feet. When an aircraft struck the cable of an LZ balloon armed with a Double Parachute Link, the cable was severed at the top and bottom by two cutting links. The aircraft thus carried away the main portion of the cable and an 8 foot diameter parachute opened at each end of the wire. Together the parachutes exerted a drag about six times as great as the engine thrust of a bomber, sufficient to stop it almost dead in its tracks, causing the victim to fall out of the sky and crash. As the cable parted from the balloon, a wire ripped off a patch which allowed the hydrogen to escape, causing the balloon to descend slowly to the ground.
Source: John Penny, A short history of No.11 Balloon Centre at Pucklechurch, 1939 to 1945
copied from here http://www.epibreren.com/ww2/raf/902..._squadron.html
Lest we forget
Very interesting John.
Thanks for that insight. Now I know what the Parachutes were for.
Rob.
"Courage is the art of being the only one who knows you're scared to death."
Never knew that, John!
Many thanks for the info.
I laugh in the face of danger - then I hide until it goes away!
Well I never.
I'm learning to fly, but I ain't got wings
Coming down is the hardest thing
Nice info John. Thanks for sharing that with us.
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