1/24th Fokker DVIII Scratch Build

[Bengt Fredén]

Bruce,

I am also considering a variant of papiér maché for my Fokker Dr.1 build. Time will tell...

All the best and happy modeling,
Bengt

[bclemens]

A week or so ago I was working on skinning the horizontal stabilizer and elevators.

I am not yet ready to present the process to you all, as I want to get through the cowl, but I just wanted to implore you to never try to cut corners on ink cartridge prices!

I've settled on printing a lozenge pattern on drafting vellum, and applying the vellum to the framework. Then the paper is tightened by moistening just as we did in the old stick and tissue model airplane days. It seems to work very well and produces just the translucent doped-fabric effect I am after.



My printer ran out of Cyan so I went to Amazon to see if I could beat the local Wal Mart price on toner. Man there were people offering compatible cartridges for almost a tenth of the price! I got excited and ordered a bunch.

When they came in the other day I noticed they looked a little funny- the plastic was a different color, it was shaped a little differently and you had to peel a tab off the back- then cyan ink spilled out onto my fingers. With some wiggling and cajoling I managed to get the ill-fitting cartridge into the printer. Thankfully the printer was happy and charged the ink and I printed a test page. No problem. I was pleased I saved a bundle!

Then I printed a lozenge sheet on vellum and...it came out a little wrinkly. Hmm...And some of the lozenges were bleeding over. Hmm...I chose to ignore these warning signs, went downstairs and proceeded to spend an hour carefully covering the top of the stabilizer. The bottom was already covered with a previous sheet (different colors on the bottom).



Well, when the glue set and I went to moisten the vellum...Crap! The freakin' cheap Chinese toner is water soluble! The cyan ran out of the print and pooled in edges and valleys of the moist paper. I can imagine what would have happened if the other 2 colors had been installed as well.

Also since the paper came out of the printer already moistened with the water-soluble cyan, it did not shrink up as it needed to- the wrinkles were permanent. Time to peel it off, clean off the glue and start over.

Well, I got the package from Amazon today with my OEM toner- 10 times as expensive, but it came out of the printer smooth and crisp. And a whole bag of Chinese knock-off toner just went in the trash.

Back on track and much smarter, if poorer. The school of hard knocks doesn't accept financial aid...
Happy modeling!

[bclemens]

Thanks, Gil and Charles for your input on cowl techniques. Truly great work. Charles, your videos are great- I can see that technique very useful for things like fenders on those cool 1950s autos Cami is making. I agree, one could go a little bolder and probably crease the paper to get sharper bends and deal with it in the finishing.

P.S. You can have the 1:16 scale Sopwith Pup cowl - gratis...,
Thanks Gil. I better save it for that Pup Charles wants to build!

I want to say I am honored and humbled to have several masters of our craft following this thread and freely offering input!

I will further explore these techniques in the future. Right now I think I am going to settle on a process that I am comfortable with and I think best leverages the tools I have at hand.

Here are some of the issues I am dealing with.

• The cowl is not perfectly round. It's very close but the firewall it needs to mate with has a bit more width than height.
• The "straight" part of the cowl (aft of the curve) widens slightly in the horizontal plane to follow the sides of the fuselage. The fuselage has somewhat of a "wedge" shape at the front.

• However it is not slanted at the top.

Therefore it becomes a rather complicated shape to craft independently. The simplest method I could think of to begin is...yes, with a jig

To begin I built a fixture that has, on the firewall end, a curve cut into it that matches the edge of the firewall. On the other end, at a distance that equals the width of the "straight" portion of the cowl, is a slightly different curve that gives the widening needed in the horizontal plane but keeps the top of the "straight" portion level in the vertical plane.



I cut and built the jig from mat board, and was able to slide a piece of 110# card stock through the two curved slots...



And was assured that the firewall end has the correct size and shape to fit and the front end has the right angle and non-angle where necessary.



It fits!



I trimmed the paper and here you see that it indeed maintains a level top in the vertical plane and...



Has the correct flare outward in the horizontal.



From here I intend to trim the paper back to the fixture and create a series of card stock rings that will make the curved portion in the front.

Happy modeling!

[eatcrow2]

Great work!! One of the best threads going, and a real treat to follow..

[cdavenport]

If you can, will you photograph each stage of your cowl build? I know that's a lot to ask, but I am really curious to see how you do this.

Obtaining compound curves is the serious weak point of paper modeling. Making any curve without a glaring seam line is even more serious to me.

Good luck with this. Don't be discouraged if it doesn't work the first time. I am currently reworking a project that just flat failed the first time I did it. So, I regrouped, rethought the design, and I'm "fixin" to go out to my shop and do the finish work on it.

ON another topic. Why are you trying to achieve a translucent effect on the lozenge fabric? If it's to show off the exquisite frame detail, great idea! If it's because you think that's the way it really was, it wasn't.

When I was on active duty, I was stationed at Wright Patterson AFB and volunteered at the USAF Museum. I did a color analysis for Leo Opdyck (WWI Aero) of German 5 color lozenge camo based on an original, unrestored wing the museum had in its storage facility (yeah, it was so cool to be doing that!). It was opaque as the night. In fact, I was curious at the time and held up the wing section to the sunlight. After 70 years (I did this in the 80s), there was no light leakage at all.

Just info to use or lose as you please, bC.

[cdavenport]

Your attention to detail is amazing! Do I see correctly that you have installed tubes so that the elevator actually works? Are you going to rig the model so that the joystick really actuates the flying surfaces? You are a god if you do that! Well, your damned close to being one even if you don't.

Please stay healthy and motivated. I check your thread everyday. It's almost like a "fix!"

[bclemens]

When I was on active duty, I was stationed at Wright Patterson AFB and volunteered at the USAF Museum. I did a color analysis for Leo Opdyck (WWI Aero) of German 5 color lozenge camo based on an original, unrestored wing the museum had in its storage facility (yeah, it was so cool to be doing that!). It was opaque as the night. In fact, I was curious at the time and held up the wing section to the sunlight. After 70 years (I did this in the 80s), there was no light leakage at all.

Charles, what an interesting point of discussion.Is it possible the sample you investigated was an early painted lozenge? I know nothing other than what I've learned on Wikipedia, but apparently some early instances of lozenge were painted and also large aircraft could have had painted lozenge.
I am using Achim Engel's Fokker DVIII replica forum thread as a primary reference for this model and his doped fabric is clearly translucent. Go to page 35 and see the second photo down.
If the fabric you saw was lozenge printed and clear doped, what do you supposed would have caused the wing to be opaque?

[bclemens]

Originally Posted by cdavenport

Your attention to detail is amazing! Do I see correctly that you have installed tubes so that the elevator actually works? Are you going to rig the model so that the joystick really actuates the flying surfaces? You are a god if you do that! Well, your damned close to being one even if you don't.

Please stay healthy and motivated. I check your thread everyday. It's almost like a "fix!"

Thanks for your kind words, Charles. No, I'm fine and this is plenty o' fun. And I'll document the cowl as I go. No, there will be no workable controls...at least not on this model. We'll see on the next

[bclemens]

Here I have temporarily pushed the paper up on the firewall side and have installed a thin ring to reinforce the shape. I pushed the paper up in order to prevent gluing the ring to the face of the fixture. I have glued it in with enough recess to allow the paper to slip onto the firewall. At this point I have also stiffened the edge of the cowl paper with CA.



I've now pushed the ring on the firewall side back in contact with the face of the jig. Now the jig is turned over and this is the front side. Here I've installed another former ring flush with the front of the jig and carefully glued it to the paper with thick CA making sure it doesn't glue to the fixture. This ring will become the base of the stacked ring assembly that will be the curved portion of the cowl.



Here I have trimmed the paper flush to the front of the ring. I now have the "straight" section of the cowl complete and ready to be released from the fixture.



Happy modeling!

[cdavenport]

Originally Posted by bclemens

When I was on active duty, I was stationed at Wright Patterson AFB and volunteered at the USAF Museum. I did a color analysis for Leo Opdyck (WWI Aero) of German 5 color lozenge camo based on an original, unrestored wing the museum had in its storage facility (yeah, it was so cool to be doing that!). It was opaque as the night. In fact, I was curious at the time and held up the wing section to the sunlight. After 70 years (I did this in the 80s), there was no light leakage at all.

Charles, what an interesting point of discussion.Is it possible the sample you investigated was an early painted lozenge? I know nothing other than what I've learned on Wikipedia, but apparently some early instances of lozenge were painted and also large aircraft could have had painted lozenge.
I am using Achim Engel's Fokker DVIII replica forum thread as a primary reference for this model and his doped fabric is clearly translucent. Go to page 35 and see the second photo down.
If the fabric you saw was lozenge printed and clear doped, what do you supposed would have caused the wing to be opaque?

Well, looks like I opened a can of worms. I can see the translucency in those photos and I also know that the restoration and reproduction efforts have gone to great effort to reproduce the fabric right down to the correct fibres and weave. I also noticed color bleed in the lozenge in Achim's build which I clearly recall absent from the fabric I examined. So, you may be correct, I may have been examining a painted fabric wing.

Certainly, there is not enough evidence to make a change in your current planning. Also, one cannot rely on vintage photos. First, they used orthographic film stock back then as opposed to panchromatic film. This altered the way colors were rendered in black & white. Ortho photos also tended to be more contrasty than the later panchromatic film.

I suppose if someone were to use your lozenge pattern and experience an issue with the translucency, they could always paint the back of the vellum. BTW, great choice for the skin. I would have never thought of that!

OK, enough on the computer! Get back to the project! LOL!