1/8 Scale Fokker Dr.1 Slow Build

[Butch Baker]

Hello everyone,

Newbie to the forum looking for some help. I'm starting a 1/8TH scale HASEGAWA DR.I kit, which will be a slow build, but have been looking forward to building this kit for a while.
The assembly starts with the engine, and I've ran into a research issue I was hoping someone on the forum could help with. After spending time researching the engine, the Oberursel UR-2 rotary engine, rated at 110hp, built by the Oberursel Motoren Gesellschaft of Frankfurt, Germany. As we know, the motor was an exact copy of the famous French LeRhone 110-hp rotary engine. The issue is the rocker arm pushrod bracket on the rear of the engine casing. This appears to be some kind of support guide for the pushrod and the kit has it molded into the case. After looking at photos of the LeRhone 110-hp rotary engine and the Oberursel UR-2 rotary engine from various books and websites, I can’t find one that shows these brackets. Does anyone know if there were any significates to the brackets, and if they were indeed on the Oberursel UR-2 and not on the LeRhone? I'm working on the cylinders at this time and will need to decide on removing these or leaving them. My research tells me to remove them. I have not found one image of the Oberursel or LeRhone 110 with these brackets except for the LeRhone 80hp shown below, and these were located on the front of the case, not the rear. Any insight would be greatly appreciated.   

Here is a picture of the manual showing the part I’m talking about:


The only photo I could locate with the brackets was this one of a LeRhone 80hp, but the brackets are located on the front of the case, not the rear.


I found the original manual for the LeRhone 110, and the manual does not show the brackets installed:

 
Here is a picture of the Red Barons Oberursel UR-2 engine, and once again, no brackets:


This LeRhone is at the NASM:




Thanks!

Butch

[Dutch522]

Well, with this kind of attention to detail you're going to fit right in around here, Butch.

I'm sure there's more knowledgable folks than me on the forum that can give you a definitive answer, but when The Vintage Aviator, Ltd built their painstaking copy of the UR-2 (based on a borrowed original, which they disassembled and made CAD models of practically every nut and bolt on) those brackets weren't on it. They did an awesome exploded poster, which you can see here:

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

I'm not sure where that Le Rhône is in your first picture, but like you noted it's an 80hp 9C, and there's a very similar one in the California Aerospace Museum with the same brackets... but they're not on most of the other 80 LRs I've seen, and not on any of the 110hp 9Js that I've run across (basically the same motor, bored out 7mm and flipped around so the intake pipes and pushrods were facing the firewall). I wonder if the Hasegawa folks just used photos of one of those 9Cs to base their kit part on...?

And given that they're on the back of the motor anyway—and pending input from people who may be privy to more & better information—my vote would just be to grind the suckers off

Dutch

[Butch Baker]

Dutch,

I was looking at that website last week, great stuff!
Yep, think that's what I'm going to do unless I hear something that proves otherwise.

Thanks Dutch!

[kensar]

The LeRhone 9C (80 hp) has the pushrods in the front of the crankcase and the 9J (110 hp) has them in the back.  You have photographic evidence that the 9J did not have the brackets, so I would go with that, since the Uberursel appears to copy the 9J.
Just my 2 cents.

[Dutch522]

I should've figured you'd have scoured out that ref, Butch! Here's something else I turned up last night, a period drawing of the rear of the Oberursel, via one of the links in the "Engines" section of the forum (Berman's "Website Reference Source..."). Wish the resolution was better, but again, I'm not seing those brackets...



Dutch

[Butch Baker]

Dutch, Kensar,

Thank both you for your help and imput on this little issue. I agree, there is plenty of support that indicates no brackets were installed. Now on to some fun creating the pushrod setup. All post some pictures once I get to that point.

Thanks again!

Butch

[Dutch522]

Hey Butch, I sent you a PM RE: references, depending on how your account is configured you might not see it except as a small "(1)" on the menu bar after "My Messages" at the top of the Forum page.

And great blog, too, BTW, I checked it out last night

Dutch

[Butch Baker]

Dutch

Just responded to you PM. Thank you for letting know as I did not notice it. Glad you liked the blog!

[Firechief]

For a look at a magnificent build of the 1/8 Dr.1, go here:

https://photos.google.com/share/AF1QipMtmwJ2aoJrcaorDQimJgwNn4shMvFZRHo0wrhE-saNTEW7aT4lmorapHDVTKbe5Q?key=eTVGZ0lnS3pVdTdCLWdsMlFlNzByV01VUEJPR3dB

I hope the link works

Firechief

[Butch Baker]

The link worked perfectly, and thank you.
This was the build that I found that inspired me to get going on my kit. The model is outstanding, magnificent build. Hope mine will eventually turn as nice, the builder is very skilled.

[KiwiZac]

I'm excited to follow along Butch. If they made a D.VII or other type I was keen on in this scale I'd be all over it but the Dr.I just doesn't appeal enough for me to make the investment, so I'm glad I get to live vicariously through builds like yours and the one Firechief linked to (wow!).

[Dutch522]

Great link, I don't know if you folks are familiar with Bob Steinbrunn's work, but he is truly a master craftsman... I used to love his articles in Fine Scale Modeler back in the 80s and 90s, when he was building 1:48 WWII aircraft. He drifted off into sailing ships for a while and I lost track of him, except for occasional articles in Ships In Scale, but he appears to have gotten back into aeroplanes in a big (literally!) way...

I still use an improvised tool he invented that I call my "Steinbrunn Saw", a #11 blade notched with a cutoff wheel in a Dremel that makes a dandy mini-razor saw:



He's probably retired now, but he used to be a corporate rotary-wing pilot flying big Sikorskys IIRC.

Dutch

[Butch Baker]

KiwiZac,

Thanks for following the build, hope to post some updates in the next week or so. Have not had much time to work on motor but progress is moving forward 
I did update my blog with some things I'm working on if your interested.

A Fokker DVII would be awesome, lots of detail can be added at this scale.

[Butch Baker]

I decided to add what I put on the blog here as well.

Here is a picture of the part prior to modification with the brackets.


The rear engine case with the brackets removed and the exhaust attachment points sanded down a little, they were a little thick.


Another modification I'm working on is the milled out area next to the cylinders. These are a pretty dominate feature on the engine and they really need to be there.


As you can see here, they are not molded into the casing. Not sure how all fix this issue yet, but I really feel it needs the added detail.


The other item I will replace is the brass pushrods supplied with the kit. They look to thick and the plastic fittings on each end are not scale at all, they just added them for a means to attach the brass pushrods to the casing.


I've decided on 1/16" steel wire polished to a shine to replace the brass ones. These look more correct for the scale. I'm going to drill a small hole into the rocker arm and slide the steel rod through down to the case. These will be installed after painting so they appear more realistic to the eye.

[Tim Mixon]

Wow!  Seeing that cylinder in your hand really puts its large size into perspective. This is going to be a monster of a build.  Looking forward to more! 

Tim