My Sterling Fokker DR-1

batjac wrote:You do realize that the Laws of Model Building state that if you take a picture of a plane in progress with a child, that same child must be photographed with the finished airplane.  You're going to have to have your daughter in a pic of the completed model, sitting cross-legged and smiling.  The rules DO allow for different clothing than in the original photos, though.

The Law Abiding Mark

HAHAHA!!!! She would be glad to do it... but she's 26 now... and will probably be "my age" by the time I finish it!

I love the old balsa build up kits, much more challenging then the foam kits. i have an old Guillows Fokker DR1 kit that I have been working on for some time now. I am toying around with the idea of throwing in a 0.20 Pee Wee engine someone gave me a long time ago. "Engine still runs, seems a shame not use it." Plus the thought of electric, batteries, speed controller etc... in an old craft seems out of place. I too thought of adding ailerons to the top wing, but it will be tricky on this kit.

That's awesome, roddie!  I started a Guillows DRI back in the late 80s, framing up most of the basic parts.  In early 2007, nearly 20yrs later, I drug it back out and finished it with a traditional tissue/dope finish.  The fumes!  It was such a challenge for me to complete at the time that I could not bear to attempt to fly it, so I installed a rubber band setup and hung it up on static display.  The triplane build was fun and inspired me to attempt building my first real RC plane, a Sig Kadet Senior.  Four months later, the maiden flight of the Senior was also my first RC flight!  I was so fired up that I finished and flew a Sig Four Star 60 kit, a TD .010-powered LaStick, a Pong Two with an .049 Black Widow, and another Pong Two with a Medallion .09.  All that in 2007!  I haven't ever finished that many planes in 1 year since.  The Sig Senior is now in pieces in the garage, the Four Star 60 died a tragic death due to rookie dumb thumbs, the Pong Twos are worn out and retired, the LaStick still flies routinely, but now has a TD .020 up front.  The Guillows DRI still hangs in my bedroom and is one of the first things I see every day when I wake up.  It's still one of my favorite models.

I remember my dad telling me, after I had the three wings and fuse built; "If you can do that.. you can build any model kit".. That was 25+ years ago.. and I haven't attempted anything that tedious since. The nice thing about that series of Sterling kits, was the full-size plan. It's a shame that not all of the model kits came with full-size plans. Sterling "did" produce some; such as the "Mono-coupe" and combat "Winder" of which I have tucked-away in my plans-box.

The 1" scale Sterling DR-1 kit could be built as a fine-scale display model, free-flight/rubber-power, control-line or radio-control. I had decided to stop construction at a point where I could choose which option. Years later I decided on RC.. and sourced some tiny nano-servos.. and started messing with the Ace-style throttle for the Cox Babe-Bee .049 reed-valve engine that Sterling recommended. An exhaust-throttle would also be a possibility, without the complexities of designing a firewall having a guide for the Ace-style "plunger-needle" to line-up with the air-intake on the Babe-Bee's back-plate with screen removed. There's also the placement of an external fuel tank.. which I would want, rather than the short-duration/run of the Babe-Bee's 5cc integral tank. A balloon-tank would be the easiest option.. and converting the tanked-Bee is as simple as running an extended fuel pick-up out through a hole drilled through the fuel-bowl.

My YouTube vid of the Ace throttle shows the tank mod.

It's a bit of a hoot...  

https://www.youtube.com/watch?v=Sy9o2WDzLqc

I built the Sterling DR-1. I still have it even though it has warped and twisted. A Cox engine is not going to balance that plane. It needs something a lot heavier like a OS Max-10. A Mccoy .098 might get you close but it's very very anemic. It has a very short nose moment making it difficult to get lead on it. Maybe a lot of lead properly secured and the cowling can hide it on the firewall.

"I'm just making a movie, honey." Love it!

Interesting, as I've never seen one of those throttle setups before.

Your dad was right regarding the difficulty of the DRI build. After finishing the Guillows version, I felt as if I had conquered Mt Everest and finally had the confidence to start building RC planes. In retrospect, many of them were easier to finish than the triplane was.

Beautiful structure and delicate, very good work!

It's good that you bring your daughter to the model ...! I wonder if she does not care to do aeromodelismo following your footsteps.
Here there are very few women model airplanes ... but there are some!

MauricioB wrote:Beautiful structure and delicate, very good work!

It's good that you bring your daughter to the model ...! I wonder if she does not care to do aeromodelismo following your footsteps.
Here there are very few women model airplanes ... but there are some!

Thank You Mauricio! I pinned the structures on top of the plan, placed on a piece of "gypsum-board" (wallboard) which holds small sewing-pins nicely. I used very small 0.6mm pins. The glue was thin cyanoacrylate for most of the structure.. and some epoxy was used in the nose-structure for strength and weight.

The model remains currently in this state.. I need to change that single rudder hinge to a more solid "pinned" type.



The wings are fragile.. and need reinforcement for engine-power. My aim is to inlay some carbon-fiber rod or tube running 1/2-span.. as "stub-spars".. top and bottom of all three wings.  

I did modify the top wing for ailerons.. and it will definitely need stiffening to prevent twisting.



The radio components weight in grams..



with engine..



LOTS of work still needed.. servo-mounts/linkages, horn-mounts.. and much stronger wing-strut/bracing-materials than what is provided/specified in the kit instructions. It will be a challenge to accomplish this.. and keep the model lightweight. Carbon-fiber materials should do the job.. if applied judiciously..  

Oh yes... my daughter LOVES the model airplanes! I have no doubt that she'll want to try flying my control-line models. She's 30 years old now!

Tee Bee wrote:"I'm just making a movie, honey."  Love it!

Interesting, as I've never seen one of those throttle setups before.  

Your dad was right regarding the difficulty of the DRI build.  After finishing the Guillows version, I felt as if I had conquered Mt Everest and finally had the confidence to start building RC planes.  In retrospect, many of them were easier to finish than the triplane was.

Yup.. I said it was a hoot! My wife (Lynne) is actually very tolerant and supportive of the hobby. She helped me to re-scale and format graphics for the laser-printing of decals (stickers actually..) for my CEF Speed-contest model.

That throttle was sold by "Ace" (designed by Ralph Cooney) years ago and came in a kit that included a plastic "guide" in the outline-shape of the Cox "Bee" backplate.. with a central nipple which would pass through the models' firewall to "guide" a supplied tapered-steel plunger (1/16" music-wire needle) into the air-intake on the engines' backplate. The little screen is removed for this. A short piece of small fuel-line is used for an adjustable servo-link.




It's considerably lighter-weight than an exhaust-throttle sleeve/ring.. but.. the use of a muffler is recommended to achieve a consistent low-rpm by holding heat in the top-end and helping to keep the plug lit.

In my vid; I started messing with the needle about halfway through.. but I've found that the best needle-setting is achieved with the throttle "wide-open".. and tuning for max rpm as one would normally. This seems to provide the best operating-range for the throttle.

Cox International reproduced the design and was selling kits a few years ago.



Their "guide-plate" is aluminum.. which raised some concern; being that it could cause metal-to-metal radio-interference when the plunger-needle moves in and out. It is however; an easy task to make your own guide for the plunger. When making-up a firewall for a prospective model; mark/punch the hole locations for mounting the engine. The engines' air-intake is exactly on-center.. therefor; drawing an "X" through the engine-mount holes, locates the point at which to drill a guide-hole. If the firewall is "thin".. provide a small hardwood block on the backside prior to drilling. A drill-press is best for doing this.. so that the guide-hole is square to the air-intake.

I really like the design. It doesn't really "choke" the venturi like you'd think it would. The fuel spray-hole in the Bees' backplate is located just inside and above the air-intake.. so when the tapered throttle-plunger advances into the backplate, it's actually metering both air and fuel.. albeit crudely.

In my opinion; the design was way ahead of its time. Nano-servo and feather-weight receiver/battery technology was decades away. "Full-house" RC controls on a 1/2A size airplane just wasn't practical back when this throttle-design was originally conceived.. or else it would have been a game-changer.

The stock Cox Bee engines weren't/aren't "powerhouses" either.. which was another negative consideration.. and the recommendation of a muffler meant having to run a non-SPI cylinder.. or loss of performance "if" running one. Today; RC model airplanes can be built MUCH lighter.. making even an anemic Bee engine a possibility. The dream has now become a reality..

It's funny that I missed that Ace throttle over the years as much of a Cox fan as I am! Thanks for sharing the info. Maybe I'll find one someday to put in my Box-O'-Cox Parts.

Ok, all this Triplane stuff got me reminiscing a bit more.  I dug out the old portable hard drive full of pics and found these of my DRI.  Like you, I talked my daughter into posing with it when it was finally finished.  She's almost 25 now.  The years have flown by.  The plane is covered in dust and hanging above this computer desk as I type this.  

Tee Bee wrote:Ok, all this Triplane stuff got me reminiscing a bit more.  I dug out the old portable hard drive full of pics and found these of my DRI.  Like you, I talked my daughter into posing with it when it was finally finished.  She's almost 25 now.  The years have flown by.  The plane is covered in dust and hanging above this computer desk as I type this.  

Nice memories.. and nice airplane too! Guessing you built yours a bit later in years than I built mine. The old photos of mine were scanned from 35mm film prints.

The Guillows DR-1 is slightly smaller than the Sterling model. The full-scale DR-1's top wingspan was 23' 6".. and the Sterling kit's is 23.5". A scale prop would be an 8" diameter one. I've actually ran (flown..) 8" x 3" woodies (JZinger brand) with a bushed-hub on a Babe Bee. It was on a profile biplane model having outlines of the Sterling DR-1 kit's pieces.. less the bottom wing. The fuse was 1/4" sheet balsa and the wings/tail-surfaces were 1/8" sheet.

You can see the resemblance in these photos..



It would actually be flown with a Cox .049 product engine and Perfect-brand wedge-tank mounted through-the-nose.




Unlike my Sterling triplane; the biplane flew numerous missions.. towed Mylar "Happy Birthday" banners.. it was lots of fun!

Here's another shot of the Sterling model. There's a Babe Bee mounted.. and that Zinger 8" wood prop.

Nice! Hope you're able to finish it someday.

Tee Bee wrote:Nice!  Hope you're able to finish it someday.

Yea.. so do I.. ....... along with a LOT of other modeling projects. Troy, I know you have at least one cat. We have three. Our youngest has a balsa fetish. I've found small balsa sticks around the house.. chewed-up. She chews on things like a teething-puppy. The litter-boxes are in the unfinished-side of the basement where my workshop is.. so there isn't much I can do to keep them away from my work. The older cats don't tend to bother anything.. but I'm very careful not to leave things out or exposed, that they can get injured by.  

When I work on a model.. I like to have my materials and tools at-hand.. ready to go for the next session. I can't leave anything out anymore. Knives.. tubes of glue.. fragile-assemblies.. small parts.. etc. will get stolen, chewed, "played-with".. knocked on the floor.. I'm more afraid of a kitty getting hurt, than anything else. As a result; I haven't gotten into any delicate building-projects for a while now.

roddie wrote:

Tee Bee wrote:Nice!  Hope you're able to finish it someday.

Yea.. so do I.. ....... along with a LOT of other modeling projects. Troy, I know you have at least one cat. We have three. Our youngest has a balsa fetish. I've found small balsa sticks around the house.. chewed-up. She chews on things like a teething-puppy. The litter-boxes are in the unfinished-side of the basement where my workshop is.. so there isn't much I can do to keep them away from my work. The older cats don't tend to bother anything.. but I'm very careful not to leave things out or exposed, that they can get injured by.  

When I work on a model.. I like to have my materials and tools at-hand.. ready to go for the next session. I can't leave anything out anymore. Knives.. tubes of glue.. fragile-assemblies.. small parts.. etc. will get stolen, chewed, "played-with".. knocked on the floor.. I'm more afraid of a kitty getting hurt, than anything else. As a result; I haven't gotten into any delicate building-projects for a while now.

If you haven't seen any episodes of "Simon's Cat " you can watch and relate:

https://m.youtube.com/watch?v=I1qHVVbYG8Y