It's just time! Time for me finally to build that Fokker Dr.I that I dreamed of building when I was 12 years old. Way back then, I had managed to acquired a set of the Joseph Nieto drawings from the Smithsonian and had studied them with near religious fervor. In the summer of 1968 I convinced my best friend that we should build a “large” exact replica and I had drawn up some enlarged plans of the fuselage by hand. In the cool of his dad's garage on a hot Southern Cal day we dreamed out loud and imagined. But the project ended before it started when we realized we didn't have more than a couple of bucks between us.

Fast forward 40 years. I still have those Nieto drawings, now yellow with age. I've looked at them often over the years and when I started RC flying and building about four years ago, I thought single-mindedly about building and flying a triplane - maybe as that third or fourth model. I started off with a Fokker EIII. And then got involved with a Nieuport 11, that I never ended up finishing but learned a lot from, and then a Flair Legionnaire, which I did finish, but haven't yet maidened. And about that time I got an offer from Chris at CD ScaleDesigns to build a prototype of his Sopwith Snipe kit. And that has been an adventure that's occupied me for the last two years. Now the Snipe is finished and awaits a few final details and its maiden flight. And then, just for good measure, there was the quickie built of a Flair Puppeteer, whose maiden flight last week was also my maiden flight as a biplane pilot. So it's time. Time to finally build that most emblematic of all WWI aircraft.

It just sort of happened. You know what they say about idle hands. I saw Les' thread about his superb little DVII with its stunning dowel fuselage - and that got me thinking. I scanned, enlarged, and printed out the side views of the Nieto plans, bought some 3mm bamboo doweling and started in. A day later I had the foundations of the fuselage. Then other things started to fall in place. I have a perfect size aluminum cowl (acquired during the EIII project) complete with the so-called “Fokker groove.” And I have a couple WB 1/6 scale Spandau kits. And a set of 5” WB wheels with the white tires. I also have the Squadron publication on the Dr.I as well as Achim Engel's Dr.I in Detail e-book.

So, it's time.

Good luck with your build Abu. How are you going to attach the bracing wires? Given any thought to pinning the joints?

Don, you da MAN!!

John

I'm with you. Just started the VK one.

Initially, this just started off as an experiment in dowel construction and I considered stopping there if things didn’t work out. But I was surprised with how easy it was and also with how straight the resulting structure was. Now that I’ve added 1/64 ply gussets the joints are solid. Of course the 49g basic bamboo frame is still extremely flexible. The gussets also helped with that but this will definitely require functional rigging. I’ve found some Kevlar-based fishing line that should do the job perfectly. The Kevlar line will be threaded through holes in the gussets, then wrapped around the dowel, and finally locked in with CA. I expect the final structure to be stronger than traditional model construction.

A word (or two, or three) on my building philosophy for the Dr.I. Typically, modelers (and most kit manufacturers) start with a standard model structure, which is then modify here and there to accommodate features of the original aircraft. I’ll be approaching the build from the opposite direction. Since I’m not building from plans but rather technical drawings, I’ve decided just to stick with the original structure to the greatest degree possible, modifying only when it seems absolutely necessary. This may turn out to be naïve, but I’m also taking this opportunity to be as “experimental” as possible. I want to try out new techniques, methods, and materials for scale construction. For example, I’ll be using bamboo for the rudder and possibly also elevator and would like to try wire trailing edges on the wings and maybe even functional aileron cables. We’ll see.

By January I hope also to be working on the prototype for the CD ScaleDesigns Albatros CI kit so the Fokker DrI will be a side project and I don’t intend to work (so) obsessively on it. It’ll be done, when it’s done.

First question: What size engine would suit a 1/6 scale triplane with a wingspan of about 47 inches? I’m thinking I’ll use my standard Saito 56.

You're welcome to post photos of your VK build here. I might be kind of fun to be able to swap ideas.

The hardest, and at the same time most satisfying, part of this sort of build is just understanding how the original was built. For this Fokker Team Schorndorf's "Fokker DrI in Detail" is absolutely invaluable. It documents the step by step construction of a full-scale replica.

http://www.collectors-edition.de/Sal...r1indetail.htm

Some people wonder why anyone would take the "modeling for God" approach of replicating features that will never see the light of day. The answer is simple: To understand and appreciate the way these ancient warbirds were built. Here's a for-instance, the rectangular notch at the bottom of the steel tube fuselage is considerably wider than the lower wing spar. Why? I don't know yet. But I'm sure I will by the time I finish the model.

Looking good, Abu. I assume you know that Williams Brothers has a 1/6 scale Le Rhone that would look close enough except for the very picky few. You will probably need noseweight anyway.

Les

Thanks, Les. Your DVII is what got me going. Yes, I've actually had two of the WB 2" scale kits and I have some doubt about the size. The website states that the total diameter is 6 1/2" but I remember it seeming a bit on the small size. I should try to get in touch with Brett at WB and get the diameter of the crankcase.

BTW, here's what the Saito 56 would look like mounted.

http://www.fokkerdr1.com
http://www.ronsandsreplicas.com/Fokker_DR1_Plans.htm
http://www.redfernplans.com/home.html

Some sites some might not know of. The plans sites are for full scale planes, but would be great to have building a scale plane. The Redfern ones had Platz as an advisor when they were drawn.

Fokker Team Schorndorf also offers full-scale drawings, I believe. But I promised myself that I wouldn't go crazy on this project and would just use the Nieto drawings as my source. They may not be completely right (few are) but I've lived with them for too long now to go making changes.

http://www.collectors-edition.de/f-t...el_english.htm

Now for a little planning. For the engine I think I'll be using either a Saito 56 or possible the 62 which is the same in all dimensions but a few grams heavier and provides a bit more umph (0.1 hp more). Cost is the same. Both fit under the cowl with a couple millimeters to spare.

With that decision made I can start thinking about how the engine can be mounted and how I need to build the recessed firewall. I could mount the engine upright and still have it fit within the cowl. But then I'd have to install a glow plug extension (and make sure there's access to get at a burned out plug). This would be the cleanest installation from a scale perspective. I could also mount it inverted which would give easy access to the plug, though I might have to "destroy" the area between the UC legs. Finally, I could mount it at an angle (90 left or right, -45 left or right). I need to think about the pros and cons of each of these options.

I also need to think about the reinforcing selected areas of the fuselage. The bamboo frame will be plenty rigid in the rear with the cross rigging but there's no rigging in the front and need that to be rock solid too. I also need to think about the attachment points for the UC and cabane struts. I could go with the standard slotted beam at all four locations. But I'd like to explore the idea of a scale mounting method that doesn't involve the standard bent music wire technique.

Another issue is that I plan to build the wings around a one-piece full length spar as per the original. I may even experiment with a scale size box spar. On the DrI, the bottom wing spar was attached in the slot in the frame (which is larger to accommodate the mounting brackets on the front and rear of the spar) and then the slot is covered over with an aluminum panel. The middle wing is also one piece and essentially laid on top of the fuse top longerons. After being bolted to the longerons, the cabane struts are attached, the top fairing is added and then the guns mounted. Finally, the top wing is bolted to the cabane struts.

I think I should have a look back through Del's GT DrI thread.

Last (for now), I'm probably start working on a "first version" of the rudder and/or stab+elevator tomorrow. I'll be using a combination of 3mm dowel, 3mm aluminum tube, 5 or 4mm square hardwood stock and some 2mm balsa strips. I'm going for the lightest possible version that is still 100% scale in outlines and structure. The plan at the moment for the first version is to use the 3mm aluminum tube to form the outline of the elevator, 4mm dowel for the elevator leading edge and 5mm hardwood for the stab trailing edge, which will give me something to screw/bolt the scale strap hinges onto. The LE on the stab will be 3mm dowel and the internal "spar" will be 4 or 5mm dowel. The ribs will be from balsa and be shaped after construction.

Material facts (weight per 10cm):

5x5mm hardwood (Japanese cypress): 1g
4x4mm hardwood (Japanese cypress): 0.6g

4mm aluminum tube: 1.5g
3mm aluminum tube: 1g

3mm hardwood dowel: 0.33g
3mm bamboo dowel: Just a bit more.



The final photo is a reminder of what a running LeRhone (Oberursel II) looks like.

Deleted post.

Already I can tell that, as on my EIII, I'm going to have to get a LOT of stuff packed up into that short nose! [:@] Mabye this is the best reason not to mount a full dummy but only do the "chin" cylinders and use the space on the firewall for other things.

I haven't done much more "wood work" on the fuse. Mostly just thinking. I did add the tail post and the gussets.

Abu. Lookin good.

You might want to check your incidences again. I have the Nieto drawings in MAN scale aircraft drawings, and on the face of MY page 2, above a bare fuselage it says that "incidence of the tail plane, 5 deg positive.

If you haven't been there yet you should peruse this build. Lots of good stuff. Particularly the cowl mounting.
http://www.rcuniverse.com/forum/m_43...tm.htm#4399390


The DR-1, DVII, and DVIII all have essentially the same tail plane incidence, and it is my theory that at "battle" speeds, that would lift the tail such that the pilot would have a better view over the front of the aircraft. I cannot imagine any other reason for it.

I would do any thing I could to keep from mounting the engine inverted. I have done that in the past, and it has usually turned out to be more trouble with starting and running than it was worth. (yes in my past life, I was an IC person). Also you would destroy the looks of the dummy engine. With the engine upright or even at 90 deg to vertical, you could have all of your dummy that shows uncluttered, and you could remove the cowl to access the glow plug. 90 degrees was always a favorite of mine because it simplified taking the exhaust out of cowlings.

Landing gear. If you make them functional, you do not need any where near the beef of unsprung gear. This is the same thing I did with my 1/6th Pietenpol. Spruce cross braces, then bolt into those.

Les

Looking at the front structure, I would guess that the streamline cheeks act like a semi-monocoque support which might explain the triangle shape, which is very stiff. I know the Camel had a big brace, instead, which probably took the torque load of the engine. Looks like it might be different engineering for the same problem.

I don't have any doubts about the strength of the original which was built of welded steel tubing. But mine's just made of bamboo. So I need to be a bit realistic and practical here and possibly do some interior ply doubling or other bracing (which would be invisible). At this point the only thing connecting the firewall to the frame would be four 3mm points of bamboo. You're probably right, though, about the stiffening effect of the ply cheeks.

In general though, I think I'll continue with the "build as per the original" concept and then modify if and when it seems prudent. I'd just rather take this approach vs. starting off with a "model structure" and trying to modify it in the direction of scale. And, Les, I think you're right on about the UC. The whole reason for music wire struts is because modelers were trying to do without a key feature of the full-scale, i.e. functional suspension. As such wires (and the fuse) had to withstand the full force of the landing. I'm planning to take something like the "bolt on" route you did.

Very nice Abu! And I might add that it looks like a nice, light structure; a sure recipe for a fine flying Fokker. I have some experience with a 1/6 scale Dr.1, and it really is a super flying airplane. I'm sure yours will be the same!

vonJ, did your DrI have the scale incidences?

I'd need to go and look at the plans again to be sure, but I think it is pretty darned close. The leading edge of the stab is raised quite a bit, a-la full scale. Of course the wings are probably not exact scale in incidence, as they have a flat bottomed airfoil instead of an undercambered airfoil. But like I said, the airplane flies really well. Very maneuvarable, and not difficult to fly at all. Take offs are quite easy with the big rudder able to keep the nose straight. Landings are interesting as with any Dr.1 model. There is a sweet spot on the approach speed that if you hit right, landings are a breeze. Too fast, and the model tends to bounce a bit and get tipsy laterally, which means one of the wing tips will contact the grass, and then around she goes! Two wheeler landings are the way to go. Trying to flare into a three pointer just results in a stall with the drag of those three wings at high angles of attack. I've flown the model many times now and have the peculiarities figured out. It's not hard to fly, just a little different.

My bad on the stab angle. I just wasn't reading the display in photoshop correctly. It is in fact, set at +5 degrees, so that's fine.

The VK has a ply doubler on the inside of the fuse. first three bays and last two for reenforcement,but it is cut out so it backs up to the sticks but is open for the most part. With the cheeks, I was thinking that even though you will supplement the structure they will be more important than just cosmetic, if you want to use the scale structure, like the functional gear.

Here's the first version of the stab. This is as scale as I can make it with the materials on hand. This version is with hardwoods (dowel and stock) and weighs 16g. Now that I've got the construction figured out, I'll make another with balsa dowels and balsa TE (but retain the 3mm hardwood dowel LE and 1.5mm bamboo ribs). I can then compare the rigidity of the two.

I might also try reducing the sizes, and use 3mm hardwood dowel for the diagonal spar and 4mm stock for the TE and 2mm dowel (or 1.5mm bamboo) for the leading edge. This would be a bit closer to scale thickness.

If this is an experement I can't wait to see the REAL thing! Very nice stuff, thanks for posting...........John

Since I'm more or less making things up as I go, I expect to have to make several versions of parts before I get them right. This stab is pretty good, but it may be heavier than it needs to be. And one thing I've learned about myself is that I tend to over-build, so I'm challenging myself on this model to make things as light as is practical, particularly in the tail area.

BTW, I found a mistake on the fuse. The vertical formers just in front of the tail post shouldn't be there! Looking again at the diagrams and other references, I realize that the line represents a single vertical steel bar in the middle that supports the skid.

VonJ, greatly looking DrI, by the way. Feel free to post photos or details.