Preferred techniques/materials?

[Charles Adams]

OK, who has built an airship model before? I recently got a Megatech kit which has a balsa frame and is supposed to be covered with tissue paper and dope. I haven't built a balsa kit since I was a teenager, so I am looking for advice. I was told to use silkspan instead of tissue. What's the best way to cut and apply the covering?

What are your favorite methods for building airships? The only examples of scratchbuilds that I have seen were all balsa frames and stretched covering. I'm sure Econokote, Monokote, or Coverite would work well but what about concealing the seams?

I've also seen quite a few paper (card) models, all from kits I'm sure. Some seem to be made of a series of truncated cones, making only an approximation of the true shape of the hull. A few more advanced models have gores which should yield a more realistic finished model. But I can't imagine assembling those without any gaps -- and what would you do to clean such a model up?

Anyway, just looking for some building tips. Anyone? :confused:

[hgraves]

as far as building the metatech airship be very carefull not to let the hull warp in an twisting fasion also when you are pining the kneel down do not allow it any chance to curl up in the direction of the sprues.
the main problem i had building the ZR3 was forming the last arc from the wood to the nose of the ship.the basa wanted to crack and form "faucets" rather than rounding out
this would be why megatech provided the nose cone and tail cones...

I used silk to cover the frame and i did an poor job of it the silk wanted to fray and after dopeing there was no way to smooth it...

if i was to do it again i would use mono kote I think...

of course seeing as i have the cut outs of the balsa formers i could do it again.

[mikee]

I built the megatach los Angeles airship and due to the fact it was My first balsa wood model it turned out kind of cheesy, I ended up buying better sprues for it from a local hobby shop, This model will turn out great with an advanced modeller though.

[MPL]

Cardstock is definitely my preferred material for model airships. I'd be too likely to accidentally damage my own work if I tried to build a frame from balsa! Plus, card is cheap and you can redesign and rebuild without too much hassle if something doesn't quite work out.

Charles, you're right about the general geometry of building an airship model hull out of cardstock - it's a series of truncated cones. So the look of the finished model is certainly a compromise, as opposed to a model built as a frame and covered with tissue/monokote/etc.

For my scratchbuilt airships, I tried to find drawings of the ships that included the actual locations of frames. Then I designed my model so the formers matched those locations, giving as close an approximation to the shape of the real thing as possible. I'm not so sure that some of the commerically available paper models were designed the same way, but that made the most sense to me.

I have one of the Megatech Graf Zeppelin kits that another builder was kind enough to send me. I think you'd have to do an awful lot of rework to produce something resembling the real Graf...the little gondolas are true examples of "stand-way-back" scale, IMO.

Several years ago, a fellow on an airship discussion group was planning to produce a 1:144 (!) Akron/Macon model, from plastic, with a big section of the hull exposed so you could see the interior details of the frame, gas bags, general structure, etc. But after negotiations with a few manufacturers, he figured the model would never be inexpensive enough to actually produce and market, so the plans fell through. I think he was shooting for $500/each and never got close.

The same group mentioned that the famed Wilhelmshavener paper model company was looking into producing an enormous 1:100 model of an airship to be determined - bets were on the Graf, or maybe Bodensee - but nothing ever came of that either. Those of us who build airships are as small a niche market as you can get!

Matso Limtiaco
Everett WA

[joec]

Depending on the scale of your airship the following method can avoid the twin problems of twisting the frame and having the stringer bend more around the rings and straight between, or break forming flat facets as hgraves mentions.

You need a pattern to scale-ie an elevation of the ship. You make each stinger by laminating two pieces of balsa together in the curved shape, you can make the full length stringer in one piece or leave a lap spice, obviously you want to lap splice if the pieces aren't long enough so the stringer is continuous.

I'd guess that a 1/16" x 1/16" stringer is about as small as you could get and that would be tricky. But if you take two 1/32" x 1/16" pieces flat to flat, pin them to your plan and drop a bit of CA here and there you have a formed stringer. It will spring back some but much more easily conform to the curve at the bow. You see a 1/32" x 1/16" strip is many times more flexible than a 1/16" x 1/16" strip, as you bend them they slip past one another.

I did not use this method on my airship, but have used it for other things, I wished I had used it for this because I had a mighty tough time at the bow and it's fairly mishapen. Again if your ship is small it might be tough to do.
Joec

[Dirigible_Nut]

I know this is an old thread,but I have just joined in the last month,and just now saw this discussion.

I have been building model rigids off, and on from scratch for years, and learned what works and what doesn't by trial and error.

I use and have used 1/16x1/16 basswood stringers for longitudals in my airship models, and I have found that a dough rolling pin works wonders in curving the stringers. Just don't mash the wood TOO hard, or you will have a curly piece of wood that is about less than 1/32 thick, and about 3/16 wide, totally usless. You have to develope a "feel" for this.

For the nose part of the stringer,roll with a firm,but medium pressure, and slowly ease up as you get to the midships part of it.Then as you roll towards the tail,increase your pressure again on it,ever so slightly,you don't want it as curved, as you did at the nose.Then ease up even more as you get toward the end of the stringer. This should get you the "airfoil" shape that will more easily conform to your rings/bulkheads, without putting twisting pressures on your frame. Also, your longitudal stringers should be applied starting putting them on from opposite sides from each other, til you have them all applied.

I used this method for the little Shenandoah model that I'm now building.

Jim.

[joec]

Jim, That certainly is a decent way of precurving the stringers too, great point. I've done that when planking small boats, and an engine car (photo). In my case it's usually basswood and there isn't much curving happening until the wood fibers are compressed so the piece usually goes from square to retangular but with a careful touch it works. Balsa is highly compressible perpendicular to the grain and so very light touch is needed. Using a rolling pin is a great idea though I hadn't thought of that. Hope you can post some pictures, I've got some in the gallery under 10' rigid airship frame. Joe

[joec]

photo now attached

[kc5pse]

I am also a fairly new member and I thought everyone would be interested in an old woodworkers trick. Actually there are two methods for shaping wood for ribs, planking, longerons and other fancy cabinet work. The first is the old tried and true steaming method that has been used in boat building for centuries where the wood is steamed, bent and clamped until dry and it then holds its shape and can be fastened into place without to much effort. The second method is even better but needs to be done with plenty of ventilation, it involves the use of ammonia. Make a tube of adequate length to hold the pieces you want to shape ( a piece of PVC pipe and a couple of end caps works great) then stuff a shop rag or sponge soaked in ammonia ( the purest you can get, household cleaning ammonia will work but it takes longer) into one end of the PVC pipe insert your longerons or whatever you are shaping into the tube also and cap both ends. The strength of the ammonia that you are using and the length of time you leave your wood in the tube to soak will determine the flexibility of the wood. A few hours to a couple of days could be required. The stronger the ammonis the less time it takes. Belive it or not I have seen 2 by 4's tied in knots using this method, the wood is like rubber. Once you have shaped your piece and is has dried out again the wood is just as strong as it was before you started. Hope this helps everyone, but be very careful handling and using the ammonia.

Kc5pse
Mike

[Charles Adams]

Interesting! Thanks for posting this. :)

[mikek]

This is my experiment with .008" aluminum. It's probably about the same size used in the ZMC2. I'm using a standing seam, it's working quite well, the test piece is quite rigid.

[joec]

This is my experiment with .008" aluminum. It's probably about the same size used in the ZMC2. I'm using a standing seam, it's working quite well, the test piece is quite rigid.

That's very interesting Mike, can you give some more detail on how you build it? .008 aluminum must be very flexible (by itself) how do the sides hold their shape. JoeC

[mikek]

Here are some construction shots. It is called a standing seam, used for roofing. Then I use a crimper to make the curve. I get the metal from a print shop next door, they use it for plates.

[joec]

Here are some construction shots. It is called a standing seam, used for roofing. Then I use a crimper to make the curve. I get the metal from a print shop next door, they use it for plates.

I'm somewhat familiar with standing seam roofs, the tool must be small, or do you join it manually? I assume you can't make it come to a point but no matter, other ways to close the ends.

Long ago our neighbors roofed their house with newspaper plates, not standing seam, just like big shingles, but it worked fine as far as I know. I'm guessing it won't be long and printing plates like those will be a think of the past.

Are you going to build a whole ship with it?

[mikek]

As far as I know, the aluminum plate is still in use. I worked for two print shops, large and small, both used aluminum plates. You can only put one image on a plate, so for newspaper, one shot is it. Then the aluminum goes to the recycler.
I want to make a larger model, using petg plastic. That's the tough stuff everything comes in now. You can't rip it, tamperproof, you have to cut it. It works just like the metal, holds a fold just fine. I'm hoping to get the plastic in metallic finish, should look cool. Just can't find a supplier to get me some here in St. Thomas.
Yes, I did the seams manually, had some welding clamps and sheet metal working tools in the shop. I'm looking for a proper sheet metal roller to do future seams, want them uniform.

[joec]

If it's similar to the plastic used for packaging it's practically indestructable. It's odd how many products are so non-durable, yet the packaging is so tough. Thanks for the updates will be interested in seeing more of it. Cap

[mikek]

Yes, the plastic is tough as hell, but it folds nice. I've used rollers, press brakes, hand brakes, and shear, but I don't know the proper name of the machine that would do a standing seam for me. It's going to have to do two folds on one edge, and three on the other. New to me. As you can see, the gores do not have straight edges like roofing.
For another project, I need a machine to make light channel in long lengths, like the gutter making machine. I need a U, maybe a C shape, with the edges turned in for more strength. Square corners are ok, not round. Like uni-strut.
I'm hoping aluminum for the channel would be available in rolls the width to make my channel. It's less than guttering in size, about half.

[joec]

Yes, the plastic is tough as hell, but it folds nice. I've used rollers, press brakes, hand brakes, and shear, but I don't know the proper name of the machine that would do a standing seam for me. It's going to have to do two folds on one edge, and three on the other. New to me. As you can see, the gores do not have straight edges like roofing.
For another project, I need a machine to make light channel in long lengths, like the gutter making machine. I need a U, maybe a C shape, with the edges turned in for more strength. Square corners are ok, not round. Like uni-strut.
I'm hoping aluminum for the channel would be available in rolls the width to make my channel. It's less than guttering in size, about half.

No the gores certainly aren't straight, maybe you need a video on how it's made:p. Seems like you'd need a unique machine to make the channels, but I'm not familiar with the seamless gutter machines.

[Catfish]

Hello,

i found that beech square strips around 2x2 mm are very useful. They will bend to whatever form you choose, even tight rounds or circles like 2-3 cm radius or less. The only problem is that you either have to use them diagonally, if you use them as lateral stringers, so the outer skin will not be flat - you certainly can work them to whatever form easily.
You can also use aluminium sheets, and saw them to radius, instead of using Balsa.
Both methods work well towards the bow of evn smaller airship models.

Greetings,
Catfish