Jump to content

UPDATE! Recon balloon for CSS Teaser


Rusty White
 Share

Recommended Posts

Mike West and I have been working (mostly Mike) on a civil war recon balloon kit. The plan is to market it separately as a stand alone kit and together with the Flagship Models CSS Teaser kit. The CSS Teaser started life as a tug and was purchased by the Confederacy and converted to a gun boat. While serving in this capacity, she was chosen to double as a recon balloon transport. For those who do not know, this small contribution gave the little ship the honor of possibly being the first US A/C carrier. I realize the Custis was the first purpose built A/C carrier, but the Teaser was probably the first US ship to carry an A/C as far as my research can verify. If someone can provide proof otherwise, please let me know. The Teaser was also the first purpose built mine (torpedo) layer/sweeper.

 

Anyway, I have been asked to post the progress on the little balloon kit. This may be a small kit, (each square you see is one inch) but it is fraught with design challenges. How does one make a balloon kit that looks real with such fragile support lines attaching the basket to the envelope? How would one show the delicate netting keeping the envelope from shooting into the air? I have posted those questions here and on other sites seeking advice and opinions. Mike West of Lone Star Models replied and we have been working together on the project since.

 

For weight savings I decided to go with a vac form design since the plan is to have the balloon supported by a series of thin brass wires attached to the basket. I was able to cobble together some CAD drawings of a typical civil war era recon balloon. To determine scale, I found a photo showing a man in the basket. Lacking any actual plans, I relied on the photographs and lithographs of recon balloons that are available. The average male back then was around 5'-9". So using the man as a scale reference, I determined the balloon diameter to be about 25 feet. Not an exact figure, but close enough. My balloon is of the "round" variety as opposed to the "teardrop" design of the likes of the Intrepid. No real reason why I went with the round design. I just liked it better.

 

Below are the master pattern and basket, a resin half mold for the vac form process, and a assembled prototype of the vac formed halves. Above that you will see the netting I have chosen for the balloon. This is where some experimenting is still needed. I want to add the netting to the resin half male, then create a "female" mold and see just how well the netting detail will come out. If it looks good, I'll proceed with production. If not, then I'll design photo etch netting for the balloon. Unfortunately, that will raise the cost of the kit (boo, hiss).

 

Below that is the pattern for the Teaser to give you an idea of scale. Together this should be a really cool kit. More to come.

 

balloon.jpg

Link to comment
Share on other sites

Hi, Rusty,

 

Your balloon looks almost exactly like the rubber squeeze bulb that is used to flush out ear wax, and the size is similar also. I find your engineering steps very interesting. Hope it all works out.

 

Ed

Link to comment
Share on other sites

Hi, Rusty,

 

Your balloon looks almost exactly like the rubber squeeze bulb that is used to flush out ear wax, and the size is similar also. I find your engineering steps very interesting. Hope it all works out.

 

Ed

 

Paint it up and stick it on a driving range. It's just smaller than a golf ball.

Link to comment
Share on other sites

  • 1 month later...

Okay, here's the latest on the recon balloon kit. I have been doing some experimenting vac forming to see just what would show up in the way of detail using a male molding process. I made several test shots (see in the background) using .03 plastic with good results. The deep scribing I thought would be required was just right and looked great on the test shots. A nice soft indention (the scribed lines) that looked just like a balloon envelope bulging out a bit between the netting.

 

master_engraved.jpg

I know this part isn't perfect, but good enough for a test shot.

 

However, upon closer observation, I noticed the detail was not consistent; lightening up at the edges. I tried a couple more test shots making the plastic softer, but no luck. I guess I just didn't have enough sucking power. I tried using a heat gun with the vacuum still on to gently heat at the base with some success. Unfortunately, getting only one good one out of three just wasn't going to get it in the business world. Such high loss would run the price of the kit too high.

 

I felt the vacuum problem could be solved by going through a professional vac former who had far more sophisticated equipment than I. I went ahead and removed the parts from the sheets for a test fitting. Everything fit just fine, but I noticed a problem that couldn't be overcome. When I matched up the halves, although I went to great effort to space the scribed lines as identical as I could, I noticed the netting still didn't match up. Scribing using only one half of the balloon meant only PRECISE spacing of the lines on half of a three dimensional ball would result in perfect alignment. The only way one could get good alignment of the netting was to scribe the lines in after the parts were put together using thin tape as a spacer. As much as I didn't like it, that's the way it will have to be because it isn't possible to vac form a solid ball.

 

vacmaster.jpg

I need to cast up 20 of these and send them to vac-former.

 

Mike said he could vac form a whole mess of these little buggers for way less than I can. So I need to cast up about 20 or so of these babies and send them to Mike. I had to add a "spacer" on the bottom of the part slightly smaller than the part itself. This will stand the part off the platen and will allow the vac form machine to draw the plastic creating a corner to show the modeler where to cut the part from the backing sheet.

 

That's where I am now. I can now begin putting together a finished model and begin working up the instructions.

 

More to come.

Link to comment
Share on other sites

What do you plan to supply for the envelope "netting"? In this small scale, I'm not sure that the "puckers" in the balloon on either side of the netting lines would actually be visble. Perhaps a simple smooth form would work just as well (with a good envelope neeting providing the "detail"), which would eliminate the scribing problems and simplify the molding process.

 

GIL :smiley16:

Link to comment
Share on other sites

What do you plan to supply for the envelope "netting"? In this small scale, I'm not sure that the "puckers" in the balloon on either side of the netting lines would actually be visble. Perhaps a simple smooth form would work just as well (with a good envelope neeting providing the "detail"), which would eliminate the scribing problems and simplify the molding process.

 

GIL :smiley16:

 

The balloon will come smooth. The modeler can easily scribe the lines or draw them on with a pencil. The balloon silk available back then was yellow, beige, pink, red, and a few others. That will give the modeler a chance to add a little color if they wish. The balloon will also comes with thin bras wire and a basket.

 

I'll build a prototype and post it here.

Link to comment
Share on other sites

  • 1 month later...

I was going to wait until I had the Teaser model completed so I could display the balloon on deck, but here's a photo of just the balloon. I'm sure someone could build it better than me.

 

The model will come with everything you need to build it as seen except for a colored pencil to draw the netting. I had to build a prototype so I could draw up the instructions sheets. There was more to it than just gluing and cutting brass rod. To make the finished model sturdy, the rod had to be bent and inserted into holes drilled in the envelope. The basket was secured firmly using "L" bent rod to give them more surface contact.

 

What color was this thing? Since everything concerning ballooning was experimental at the time, I could only assume they used whatever color of silk they could find in large quantities. Since purple was fashionable at the time, why not?

 

The netting was drawn on using a colored pencil and tape for a straight edge.

 

I am quite pleased with the finished product. This ought to look uber cool on the bow of my Teaser model depicting the US's first aircraft carrier circa 1862!

 

 

reconbal.jpg

Link to comment
Share on other sites

Really nice looking and very interesting! I never really gave it much thought but building one of these ballons would be very costly with taht much silk being needed.

Link to comment
Share on other sites

Looks good Rusty, especially for a quick build. Looks like anyone who wants to go to town on it will have a good item to start on!

 

GIL :smiley16:

 

Most of the time building it was spent deciding how to go about the various steps (only 5) to make the balloon as sturdy as possible. Then I spent time just watching stuff dry. Build time was only about 3 hours not including watching the paint dry. Yeah, I know it's an Oklahoma joke. :smiley17:

Link to comment
Share on other sites

 Share

×
×
  • Create New...