Fokker Dr.I by Torbogdan - FINISHED - Model Airways

[Torbogdan]

Don't worry Vossiewulf. They are there. You will see them when I can get some better pictures😀👍

[Torbogdan]

A better picture of the engine. It is funny to compare it with Vossiewulfs picture. My pushrods are thinner than what they said in the instructions. Instructions said to use 1,6mm thick brass rod. I used .8mm rod. I used .4mm rod for the wire from the spark plugs, but according to the picture should have used even thinner wire. Oh well, it is a learning process.

Two of the instruments, will get some gloss varnish over the "instrument" to simulate glass and to protect it. Control yoke painted according to instructions. Don´t worry about the missing paint on the yoke, I will touch it up when it is glued in place.

The same stuff, ammo drum to the right and spent cartridge can to the bottom. These will be sanded to a better shape and then painted either brown or grey. 

[vossiewulf]

For future reference, Micro Krystal Clear is made to do glass for instruments (on larger scales) and windows (smaller scales), and works pretty well.

[Torbogdan]

I´ve put some work into the ammo cans, spent cartridge can and fuel tank. Gluing and sanding, gluing and sanding is the recipe. First one, then wait and the other and repeat again and again. 

 

I will get some pictures at the end of the week! I´m eagerly awaiting the arrival of my book which Vossiewulf recommended. Then I guess the placement of all internal parts will be a breeze

[Torbogdan]

This will be a rant, if you do not like rants, do not read it..

 

I´m very frustrated and annoyed and plain angry for the moment as things do not go even close to plan. 

 

I started on the front mount accessory. It is molded white metal with little "nubs" on it. You are supposed to put a short "tube" of heat shrink tubing on it and put a wire inside it. All very well thought out but it does not work. The nub is too short to hold the heat shrunk tubing. Even supergluing afterwards is not enough. So what I recommend is to take the part EC 10 front mount accessories and snip of the nubs with a plier and sand flat. Then drill holes and insert a short brass rod. Maybe 10mm long. Then put the heat shrink tubing and wire on it and now it will work. Now the tubing have a longer "pin" to stick to, so to speak. The original nubs on the part are just too short.

 

I also replaced the wires that run from the mount with either black rubber rigging thread or a thicker round rubber band (for the MG:s). The metal wires supplied in the kit will work but are fairly stiff and is therefore very difficult to work with. (see picture below, after redoing it with the rubber rigging thread)

 

First I followed instructions and used the wire but it was stiff and got tangled in the fuselage of the aircraft and was basically a pain to try to use. Now it is much easier as the thread is more like string and therefore easier to "guide" through the maze of the aircraft with all its wires and stuff.

 

 

Then the control yoke is supposed to fit on the stick in the picture below the one below this text. Trouble is where to two pieces meet is very difficult to glue. the control yoke is about 2 mm in diameter and the stick is also 2mm in diameter. So it is impossible to drill a hole in the yoke to slip it on the stick. Sanding the stick to a thinner diameter is very very difficult as it is already mounted in the cockpit and is very difficult to get a file or sanding stick in there. Just gluing it on won´t work as the contact area is too small for the glue to form a strong bond. If I hade been made aware of this much earlier in the building process I could have fixed it quite easily but now it is difficult as the stick is already in the cockpit with lots of things in the way. If you have some heat shrink tubing you could slip it over the stick and the end of the yoke and it is done but I do not have it.

 

Finally I cut off the stick from the cockpit and replaced it with a 1,6mm brass rod (so I could drill a hole in the square part at the end of the stick, where it joins the rest of the assembly) and drilled a corresponding hole in the yoke. But it was a pain doing it as getting the drill into the cockpit area was a difficult.

 

All in all today have been a bad day with lots of frustration and troubles. Lots of it could have been avoided if certain things had been pointed out earlier in the building process. For example to make sure that the control yoke fits the stick. Or basically sand the stick to a thinner diameter before putting it in the cockpit, then there would have been no problem.

 

 

Spent cartridge can added. These pictures show the wiring before I redid it. Long stiff wires that are extremely difficult to work with.

 

 

 

 

[vossiewulf]

I understand Tor, I got halfway through an Alb. D.V before it got killed in a move and I decided not to re-try as they are just not that great kits and even someone just trying to build something reasonably good out of the box has problems, as you have had.

 

The up side (which is pretty big) is no one offers anything like it. But they've always looked like airplane models designed by ship modelers who don't know much about flying and they would do themselves a big favor by hiring an experienced RC aircraft designer to redo them for higher accuracy. Then there is the inexplicable obsession with white metal, it's inexplicable as you can see the masters were reasonably good, so if they'd just taken that master and cast the part in resin it would have looked nice and been easy to work with if you want to add detail. Instead they use white metal and it's pitted and bumps are everywhere and they take a ton of effort just to get in basically usable state.

 

But I doubt they have much impetus to do a redesign when no one else is competing, so there's room for someone to step in and do better.

[reklein]

I've wondered about the white metal castings too. They are so heavy, in the case of engine modeling ,that the supporting structure is too flimsy to adequately hold everything up making the model unduly fragile. I agree about the resin castings. Not being metal doesn't make the model any less valuable or accurate.

[Torbogdan]

Some parts, bolts for the propeller, engine, fuel tank partly done, machine guns, carburetor and air intakes and parts for the pilots seat.

 

Up to the left are two pieces of flat aluminum, they are the missing parts for the fuel tank. I, of course, bent them "the wrong way". Trying to bend it back, it broke of course. Thin aluminum can´t bend often without breaking... I´ll drink a beer tomorrow and use the can for repair material

Som

Cockpit are slowly getting done, the grey box is the MG ammo box.

Another angle. Today was a productive day. It went slow but at least all went according to plan, no mistakes!

[Torbogdan]

Yesterday I got the book I ordered, Fokker Dr I the aces´aircraft, a great book! Lots of information and awesome pictures and drawings. I wish I had this book when I started building six months ago.

 

Lots of thanks to Vossiewulf who pointed me in the right direction where I could find the book

[vossiewulf]

39 minutes ago, Torbogdan said:

Yesterday I got the book I ordered, Fokker Dr I the aces´aircraft, a great book! Lots of information and awesome pictures and drawings. I wish I had this book when I started building six months ago.

 

Lots of thanks to Vossiewulf who pointed me in the right direction where I could find the book

I think I may have made you aware of it and that it's THE book to have for building Dr.I models, but it was Ron Thibault who saw that they were in stock again and pointed that out. Thank him for continuing to check

 

[thibaultron]

Its a nogo on 3D printing the cylinders, for the Le Rhone/UR2 engines. There are 33 fins in a actual 22CM length, and the minimum thickness for the Shapeways detail plastic is ~.5CM for a supported wall/fin, and ~1CM for an unsupported wall, AKA a fin. This is for a cylinder scaled to 1/16th.

 

A built up PE stack might do it. You would need some combination that comes out to .0163" or .0164" thick for each fin and spacer(s) combination. It comes out to .666 real CM from top of one fin to the bottom of the "gap".

[CDW]

A friend bought a 3D printer and has slowly been learning to tweak it, use it, and learn it's limitations. He was telling me something similar to what Ron said when he told me the difficulty in 3D printing a pilot bust figure. He said the problem comes when the printer goes to do (for example) a nose. The bottom of the nose has nothing to rest upon and becomes as Ron said, "an unsupported wall". As a result, it sags and turns out to be a blob rather than a nose.

Now, there are ways around that problem, but it's advanced stuff and that's probably not something worth the time and effort for Shapeways to do. But it can be done.

[vossiewulf]

That's all standard 3d printing stuff, there are multiple packages designed specifically to set up a model for 3d printing with the appropriate supports and orientation and they check minimum feature size. The latter you have to check and know before you begin modeling, you can't just model whatever and expect it to 3d print at any scale. You have to plan for and create different versions of your models at various scales as the minimum feature size shrinks relative to the size of the model as you go up in scale.

 

None of them are insurmountable, but it's also something unlikely to be navigated by someone who is not a very experienced modeler. Once I get my desktop up and running again I plan to work on printing some of my work through Shapeways and maybe offering some models useful to people here and in other (physical) modeling areas, I'll let folks know what I learn.

[thibaultron]

Received the 1/6th Le Rhone 80HP engine model kit. Unfortunatly the 80HP has the valve pushrods at the front of the crankcase, and the 110HP has them at the rear! Did not notice the difference until after the kit arrived. May have to find a Hagasawa 1/8 Le Rhone kit.

 

[vossiewulf]

Worse than the pushrods- those could be fixed without too much pain- are the exhausts. In the 9J they go to the back half of the crankcase, and I think the 9j has a larger-diameter crankcase too that provides a bit more room for the exhaust, and to make those you need to make a blank with baking clay and then carve it down into a master for casting. Much better plan to wait and get a real 110.

[Torbogdan]

Due to work I have not have had time to build or update. Now I will be on vacation for a few weeks so updates will be fewer and slower

 

But don´t worry, I will continue to build!

[thibaultron]

Enjoy your vacation!

[Nirvana]

7 hours ago, Torbogdan said:

Due to work I have not have had time to build or update. Now I will be on vacation for a few weeks so updates will be fewer and slower

 

But don´t worry, I will continue to build!

Ha en trevlig semester!

Have a  nice vacation, we will all be here once you are back.

[vossiewulf]

4 hours ago, Nirvana said:

Ha en trevlig semester!

Ok I had to look that up and yes in fact "semester" in Swedish means "holiday". Swedish students going to college in the US must have an amusing time scheduling brutal classes for their first and second "holidays" each year

 

[thibaultron]

I broke down and bought one the Hagasawa Le Rhones. Should be here next week. Haven't decided whether to keep or resell the Williams Brothers 80HP model.

 

When the 110HP arrives, I'll post some pictures of the parts. I also bought one of there Camel engines, its coming from Canada.

[vossiewulf]

1 hour ago, thibaultron said:

I broke down and bought one the Hagasawa Le Rhones. Should be here next week. Haven't decided whether to keep or resell the Williams Brothers 80HP model.

 

When the 110HP arrives, I'll post some pictures of the parts. I also bought one of there Camel engines, its coming from Canada.

There were several Camel engines, from Le Rhone and Clerget and Bentley, and they all flew a bit differently. Josef Jacobs, the German ace who flew the Dr.I longer than anyone preferred the Clerget, and provided rewards to front-line troops who let him know about downed Clerget Camels with undamaged engines. Most of the other information I have says the Bentley Br.I versions were the best, with a nominal 150hp, with Clerget having a nominal 130hp, but only the RNAS used Bentley-powered Camels.

 

Also your Dr.I book should provide lots of detail reference pics. I need to find someone who knows the whole story, but I'm a bit confused by it; one the one hand Oberursel signed a license agreement with Gnome/Le Rhone in 1914 (who thought that was a good idea in France also?) that included the "lambda" 9 cylinder engine, Oberursel didn't begin design and development on it until 1917 and Le Rhone maybe in 1916? So I'm confused by the fact that I can't find any reference to any differences between the 9J and the UR.II, everything I can find says they're identical engines, and that makes no sense as no engine ever survived the transition from design drawings to working engines without changes. And I also can't find any information saying Oberursel copied captured 9Js, what I do have says their design engineers started building prototypes in 1917 and they went through an independent development and testing process before Idflieg certified it for production.

[thibaultron]

One source I found, said that the Germans would reuse Le Rhones in the DR.1, if they captured any. Similar to your post.

[Gerhardvienna]

Maybe interesting for the research about the Oberursel/ Le Rhone engines

https://www.rolls-royce.com/~/media/Files/R/Rolls-Royce/documents/country/deutschland/broschre-100-jahre-flugmotorenbau-in-oberursel-15082013-tcm250-51336.pdf

 

Regards

Gerhard

[vossiewulf]

Oh yeah the consensus at the time was the French-built engines were better so it wasn't uncommon to replace a UR.II with a Le Rhone on Dr.Is. Josef Jacobs is the only one I'm aware of that mounted a Clerget on a Dr.I. The problem wasn't just the quality of the engine build however, it was the oil, the Germans ran short of castor oil and tried all sorts of ersatz products with little success, and the engines suffered as a result.

 

Actually if there was a severe failure by the German air industry, it was in engine development, they fell behind in 1916 and were falling farther behind at the end of the war with the allies fielding multiple fighter aircraft with 220+hp engines, with the Dolphin having a 300hp engine, while the "fast" version of Germany's top front-line fighter, the D.VII was flying with a 180hp BMW IIIa and the Albatros D.Vas were mostly still flying with the Mercedes D.III(a or au) most still developing 165hp but the aus could push it up to 185hp.

 

Actually the Albatros D.V is a very good example, because meanwhile the Austrians had turned the earlier Albatros D.III they licensed into a MUCH better fighter than either the D.III or D.V versions the Germans flew, except for the absurd Schwarsloze MGs. Oeffag, the Austrian manufacturer, immediately realized the problem with the single spar lower wing leading to resonance and the resultant loss of the lower wing. After a bunch of German pilots were killed Albatros slapped a short strut from the wing V-strut to the lower wing leading edge which helped, but the German Albatrosen were never good divers, you could only push that lower wing so far. The Oeffag engineers instead redsigned the lower wing with two spars, redesigned the lower part of the v-struts and their mounting, and the OEF aircraft never had that resonance and could be dived much harder.

 

The lowest hp engines the Austrians used was the 185hp Daimler-Benz, the other two Albatros series they built had the 200hp and 225hp Daimler-Benz engines. Then they realized the plane was faster without its spinner, something that wasn't too hard to verify since the one thing OEF engineers couldn't do was keep their spinners from falling off the plane in flight. So they redesigned the forward fuselage into a simple rounded shape, and got another 9mph increase. I've often wondered how the Western Front might have played out different had Albatros dumped their D.V and built the OEF D.IIIs instead.

 

Series 253 OEF Albatros D.III with redesigned forward fuselage and 225hp Daimler Benz, probably 30mph faster than the Albatros D.Va.

 

[thibaultron]

I got the two Hagasawa engine kits. The detailing looks good, at least good enough for me.

 

The Le Rhone 110HP

 

The Clerget 130HP

A close up of the cylinder and vale rocker arm parts.

 

 

 

 

[vossiewulf]

Just make sure you have some of the thin sanding film that can be creased really sharply, best thing I've found for hitting both sides of the eleventy thousand cooling fin seams to make them as invisible as possible. The fit should be good but if you get lots of squeezeout or empty seams... think of an old salt squinting and shaking his pipe at you while saying "give up on perfection now boy, for that way lies death. Death... and MADNESS!"

[thibaultron]

Liquid plastic cement.

[Gerhardvienna]

I addition to the "engine discussion" I finally found the site I was lokking for:

http://thevintageaviator.co.nz/projects/oberursel-engine/oberursel-ur-ii-rotary-engine-build-history

 

 

Regards

Gerhard

[thibaultron]

Le Rhone and Clerget Hagasawa 1/8th scale engine builds. you'll have to copy and paste two of them.

 

https://mbiqmodels.com/2016/03/09/fokker-dr-1-hasegawa-18-part-2-engine/

 

 

 

https://mbiqmodels.com/2014/10/12/sopwith-camel-f1-hasegawa-18-part-1-clerget-9b-rotary-radial-engine/

 

 

 

 

 

https://mbiqmodels.com/2014/10/27/sopwith-camel-f1-hasegawa-18-part-2-prop-interplane-and-cabane-struts/

 

 

 

 

[vossiewulf]

Make sure you check out Uschi's metal powder offerings, those kits are perfect applications for them. They are actually quite easy to use and can produce metal finishes that are exceptionally realistic.

 

This one shows off some of his leather decals and wood paints/decals.

Note both of these show a Mercedes D.IIIa/au engine as used by the Albatrosen and early Fokker D.VIIs  

And here's a guy doing a terrible job of using them on your 80hp Le Rhone kit, rough sanded with no undercoat and it still looks pretty good.

 

The only downside is metal finishes like this are the least forgiving in existence, and in fact if you had a need to find every single scratch on a surface down to near atomic levels, rub some metal powder on and you can see them pretty easily.

 

It's not quite that bad of course but you get the point, best results will be to use the same undercoats he recommends on a surface that's been sanded/polished to the highest grit you can stand. Novus Plastic Polish works very well here, you sand to maybe 1200/1500 and the #2 fine scratch remover will take out all of those scratches and leave you with a glass finish and can be done by hand but felt points of various shapes for your rotary tool can help speed up things considerably.

 

This is a glider I made painted Tamiya flat black and rubbed over with one of the powders. Tragically, being made of balsa, it moved way too much and the finish got all wrinkled a few months later. So not recommended over wood.