Started an experiment tonite....

[Sabre F-86]

I've been following some of the paper to plastic discussions going on here and on other forums, So I thought i'd give it a whirl.

 

I picked up a Wilhelmshaven kit of a Dornier DO-15 Wal, and expanded it out to 1/32 scale from 1/50th a couple of weeks ago. Anyway, tonite I started working on it. I cut out the patterns for the basic hull, and sprayed them with 3M Super 77 adhesive. Once it was tacky I put the keel and frame patterns on a sheet of .020 stock and the sides on a sheet of .015 stock. Heres a photo of the deal so far.

 

 

I started cutting parts out and getting them fitted but no photos yet. I have to figure out how the cockpit goes together before I do anything drastic and start applying glue. There is next to no information out there that I've found so far so its going to be a bit of a guess.

 

More as things progress.

 

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Sabre

[Jack]

Sabre that is looking promising, what are those dimensions on the Wal in 1/32 scale, must be a biggie i'm sure!!

 

regards,

Jack

[Sabre F-86]

Sabre that is looking promising, what are those dimensions on the Wal in 1/32 scale, must be a biggie i'm sure!!

 

regards,

Jack

 

 

I can't really tell. The kit has no dimensions on it at all. I'll know better when I get the hull put together. Its about 16 inches nose to tail. Span will be somewhere between 25-26 inches.

 

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Sabre

[ssculptor]

Yes!

Go for it!

There are many wonderful planes that have been modeled in paper card models.

All we have to do is enlarge them to 1/32 scale and following your method and the methods of others, start building a whole new array of aircraft.

Also, these paper card models are pretty reasonable in cost. I think the most I even spent for one was $25 and that was a four engine bomber.

Stephen the cheap.

[Sabre F-86]

Work progresses on the Wal. A correction first, the hull actually comes out to 19 3/8th long. I spent part of this evening opening up the area for the cockpit, and glueing the keel and frames to the main deck. So far so good but I gotta say, Symetrical wasn't a word in the designers vocabulary. I'll be filling in missing bits n filing away extra stuff for a while before I get to put the sides on. Both sides of the engine nacelles are different, so I picked the one with the squared off front and duplicated it. I bought a scroll saw some time ago anticipating its usefulnes for such a job and its working just fine.

 

I suspect the airfoil thats cut out on the bottom of the nacelles is way off, so I may end up having to redo them. Not a great problem, they are a simple box shape. The fun part is going to be doing the wings. This particular paper model has no ribs at all, only a box spar and the wing skins. I've got to find a 3 view somewhere which will give me the aspect ration for the wing as I suspect there is a lot more material then need to make up the proper airfoil shape. If I use the paper pattern and then flatten out the foil the aspect ratio will be wrong, too much chord for the span. The foil appears to be very flat, something like 7-8% maximum thickness. The kit looks like they want you to use a Clark Y or similar.

 

Any way, more photos tomorrow if the sun comes out. My shop lighting sucks.

 

 

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Sabre

[Allok]

That looks like an awesome project!

Can't wait to see more.

[Sabre F-86]

Been making some progress. The Hull frame is pretty solid now, and the asymetry is mostly taken care of. A bit more work with the file on one side where I had to add material and it should be ready for the side skins. Those are now cut to shape and the portholes have been opened up. I may add a couple of stringers to the framework to add support for the skins.

 

I have the wing and tail plane skins cut out of 015 material. Im pretty sure I need to build some sort of interior structure, ribs n all. Just the skin and a spar wont' do it.

 

A question to all of you. What is the best way to get sharp bends on thin sheet? Like the leading edge? A pan full of hot water? Blow Dryer and former? I've tried to bend a test set to make up the wing leading edge and its not giving me a tight enough bend. The tailplane n rudder will be even worse. Any suggestions would be appreciated.

 

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Sabre

[Butler]

The best way I found was to form it around something like a paintbrush handle and build up the radius fairly slowly, rubbing the styrene with fingers or on clothing to the warm it up and stop it snapping

[Sabre F-86]

Butler, I just had a look at your Meteor build. I musta missed it during my scans. Very interesting build log, lot of good stuff there for me. Im going to give the rubbing styrene a go tonite n see how it works out. Let you know in a couple of days.

 

Sabre

[Sabre F-86]

Been puttering along, and after achieving something approaching symetry for the frames, I've gotten the hull sides on and trimmed to meet the framework. I ended up making new sides as the originals in .015 plastic were way too flimsy. The new ones are .030 and much better.

 

The bottom sheet pattern ended up to be a bit undersized so I'm going to make up a new front section, with the curve for the bow, and use the rear end as is with a splice in the center where its dead flat. I suppose once I get that on, and sealed it will be time to make up a cradle for the hull. The easy part is the upper deck, simple flat sheets curved over a spine. Piece o cake. Making up the cockpit coaming and the various bits on the fore deck should take a single night. After that its time to start work on the sponsons and the wing support platform.

 

The engine sides are being framed for the wrap around skin, and that sheet is cut to shape and ready for the installation. I've also roughed out the vertical fin and rudder, I should be finishing that tomorrow. The stabilizers are cut out and once the spar is made up I'll be able to bend them and finish them.

 

Anyway its certainly a learning experience. I'm still not sure about the wing, with no structure I may end up building a classic leading edge, spar, trailing edge and a whack of ribs to get the sheet to work proper. A 27 5/8 wing, made with just the skin and only a spar doesn't look like its going to work very well. I expect it will give a nice looking wing but it will be subject to a lot of flexing without an interior structure. Perhaps I'll make up a small test section to see before I go nuts on a frame.

 

I'm still puzzling out various aspects of the German language instructions too. Man, its been a long time since highschool German class.

 

I'll try to get some photos before I close up the hull with the bottom plate as well as the other parts as they progress.

 

Sabre

[Sabre F-86]

Ok, some photos of the progress.

 

First shot is a general look at the hull, still open at the bottom. Off to the side we have the rudder and fin.

 

 

 

Next, a closer veiw of the front end. I had to add an intermediate bulkhead just forward of the cockpit, as the curve of the plating on the bow is something fierce and the sheeting wasn't wanting to conform. So, after I opened up the cockpit hole, I added a partial bulkhead which goes across from chine to chine. I tried to fit the skin again, and it was now conforming better but still way wicked in the curve. I also found that to get the curve in, the skin had a tendency to push the first bulkhead toward the rear, so additional bracing was added.

 

 

 

The next photo is the bow, right side up and you can really see the way the curve is developed, a severe bend, with a bit of a twist. The side skins are pretty much straight from tail to nose along the top edge, allowing the hull to be build upside down and squared up. Once the skin is on tight over most of its length, you add the twist, and pull the skin round hard, gluing as you go. Once tight to the stem, a clamp holds it tight. Trim the excess and apply the other side. Of course now you don't have a way to clamp the nose, so about 6 inches of masking tape really lets you heave it in tight.

 

 

 

The fourth shot is the hull inverted and the bottom skin laid on approximately as it will fit. As noted above the pattern was a bit off, So I cut it in two at the step and moved the bow section forward about 1.5cm. This gave the extra material needed, and its on now. The split in the nose is to allow for the skin to be curved in two directions, veed across the hull and rounded fore and aft. Again the pattern was off, and the notch ended up being skewed off to the side. No matter, once it was on and cured, the gap ended up being about an 1/8 wide and a bit of extra sheet and some CA fixed that.

 

 

 

Pic 5 is the rudder and fin, with the spar and rudder post in, but the trailing edge and top need to be thinned and then glued. Looking at it, you can see the shadow of the spar and post. In hind sight, I should have made them both a bit taller and rounded the upper end as I now have a hard spot at the top of the post, and bending the skin to glue it will make that worse. I may scab in a small bit with the rounded top before I go to glue the ends. The spar is a bit harder to fix as its tapered and only about 1/8 wide at the top end. I'm also going to run some CA down the leading edge to thicken it up and prevent cracking. This will allow me to sand the leading edge a bit more rounded instead of the sharp angle that it has now. It looks more like a jet fin than a 1920s vintage leading edge. My bending technique needs some more work. My scoring tool was too thin, and I did the scoring on a hard surface, instead of the cutting pad we all normaly use. I took it off the desk so I could have a flat surface to build the hull on, and was just too lazy to go get it again.

 

 

 

These photos were all taken around noon, before I went to work. I just crawled out of the dungeon, having spent the last couple of hours putting on the bottom skin and cleaning up the joints. I've scarfed in the 1.5 cm strip to bridge the gap on the bottom skin and so far its looking pretty good. I've marked the windows back on using the old side skins, and marked the location for the sponsons as well. The stabilizer/elevators are both now bent, and ready for the spars. The engine box is trued up, and glued together, waiting for me to cut the panel that curves round the front, top and rear. The one I had already cut is too narrow. Somewhere I missed a measurement and made the engine frame about a 1/16 too wide. DUH! Tomorrow I'll be starting to work on the upper decking, installing the spine and then the decking. A bit of work left to do on the hull bottom at the aft end, something didn't quite go right there, and I have some gaps to fill with sheeting. I'll also be starting on the "wasserkupfe", that sled shaped thing on the bottom which acts as a step, and the other under side sheetmetal and the rudder. I'll grab some more photos as well.

 

 

Sabre

[Sabre F-86]

Well, the day started off nasty, my truck made some expensive noises, and is now Tango Uniform. Battery, alternator and maybe even a nifty computer box of some sort.

 

On the plus side, it rained buckets all day, my plans were shot to go work on the boat, so I've been banging away at the Wal. Things are looking very good so far. I've pretty much finished the bottom of the hull, the wasserkupfe and the secondary step are completed. All the dings n dents are pretty much filled. These photos were taken in the afternoon, and cover the work done in the last post.

 

 

 

 

 

Since these were taken, I've added the upper deck spine, and started on the substructure for the sponsons. I've cut out the total wing skin, and am starting the slow process of getting the leading edge curve into it. Tomorrow I'll see what the truck is doing, what the weathers doing and most likely disappear into the dungeon again. On the plate are completion of the sponsons, completion of the upper decking and possibley the cockpit coaming, windscreen fairing, and the forward hatch.

 

Sabre

[blackbetty]

very nice work!

reminds me of my shipbuilding days

[Derek B]

Nice going Sabre...Where's the popcorn icon when you need one!

 

Derek

[Sabre F-86]

You know, this model is really weird. I've been looking at all the photos and drawings I can find, and it seems that the designer of this kit took features from all of them and amalgamated them into a generic Wal. There are no dimensions given for this specific model, only the statement that the span started out at 22m and ended up enlarged to 27m. Engines were what ever the customer wanted, and the tail fin changed from one aircraft to the next. To my mind, the closest photo or drawing to what I'm building is actually a series of Soviet aircraft used in the early 30s. Very odd. It does state that the model is patterned after the 1932 Civil model which Lufthansa used, but thats about it. From what I've found the DO-15 that entered Luftwaffe service in the early 30s was also based on the same model.

 

heres a link to a photo of the Soviet ones: http://ram-home.com/ram-old/wal-ap1p95-1.jpg

 

Anyway, on to the build. Not having a vehicle, I stayed home for the weekend and continued sacrificing plastic to the model gods. With only a few minor niggles it appears the gods are pleased. The upper deck went on without a hitch, after the spine was solidly glued on. The bow hatch was fitted, and the sponson spars or support boxes were made up. These are quite interesting as they are rhombode in shape, sort of like a pyramid with a twist to it. For a while it appeared as if the draftsman was stoned, nothing seemed to meet or fit, but after I go the first two sides glued in, I decided to actually fold the paper pattern and see what it looked like. Thats when you find out it all has to twist about 20 degrees in order for the sides to all line up. Once the glue hardened, a quick zip with the sanding stick and they were solidly attached. The next step was to attach the skins, which were done top and bottom together, glued at the leading edge on an angle to match the root rib, and then formed around the root, gluing as we went. The right side sponson is pretty much completed, and the left one needs some sheet trimmed off the trailing edge but should go together with the same ease the right side one did.

 

I've decided to put the various strakes on using 40thou square rod, but haven't got enough to do the whole model. So for now, the upper deck will be done, the rest will need to wait til I can order more. All in all theres probably about 15-20 linear feet of strip needed to do this model. If I do the upper deck, I can proceed to doing the wing mount platform without any delays.

 

I had another look at the instructions, and the parts for the wing. I folded up the paper spar and cut out a strip of paper to represent the wing skin, wrapped it round the spar and was quick to realize that my initial impression was mistaken. I had envisioned the spar laid on its side, 90 degrees off its true position. Having seen that, I made up a quicky spar section, and a strip of plastic to represent the wing skin. Spar glued in place, the skin pulled around and mated on the trailing edge, and there you have a reasonable facsimily of a Clark Y airfoil. However the bend for the leading edge still wasn't happening, so I finally dug out a piece of 1/4 inch doweling. I then made up a couple of half ribs, for the airfoil forward of the spar, and notched them for the dowel. A bit of trimming and I now have a solid airfoil. So if all goes well I should be able to make up a very solid wing, and sheet it in .030 on both sides.

 

In between sponsons and wing bits, I decided I didn't like the rudder and fin, so it got revamped. The rudder is now seperate and can be posed offset. I'm about to do the stabilizers and elevators the same way. Also the ailerons, once I get the wing to that point that I can cut them out.

 

For display, the drawings give you a nice little stand, similar to what you have with model ships, but looking at some photos of the beach handling gear, I'll end up making up the huge wheels that attach to the sponsons and a dolly for the tail. If you look at the photo above you can see one wheel attached to the left sponson while others float in the surf. I gather they were large wooden disks, hollow so they would float enough so that they could be wrestled into place on a removable axle going into the sponson.

 

And so it goes.

 

If there is anyone out there who has any references on the Wal with cockpit shots, I'd love to have them.

 

 

Sabre