I picked up this partially built model manufactured by Eureka Hobby.

Old to say the least, if nothing else the plans, three sheets, are great!

Eureka inked their name on the balsa wood. This model is R/C but I expect to go CL with it.

Has washout, but the bottom of the wings aren't sheeted, I can probably take it out. the thing is really bad, one of the worst builds I've seen. Looks like it was passed around over the years to a few modelers, there's evidence of this.

My interest is if anyone knows of this Company?

Thanks,

CB

The Eureka, I'm referring to was the 60's.

CB

Back in the day Eureka Scale Kits were the ultimate.   There were several different scale models.  Club member built the C-47 with .35's for power.   No throttle back then and on 60 foot lines he had to kick off his shoes for traction when ever he flew it.   Needless to say he only flew it in contests.   I did have the A-26 or A-25 that Meriwether built with two K&B .35 Greenhead with throttles.   Was planning on flying it until I test ran the engines.   I don't think it would have stayed together for a flight.   Engines were removed and the plane was chopped up.   

I picked up this partially built model manufactured by Eureka Hobby.
Old to say the least, if nothing else the plans, three sheets, are great!
Eureka inked their name on the balsa wood. This model is R/C but I expect to go CL with it.

Has washout, but the bottom of the wings aren't sheeted, I can probably take it out. the thing is really bad, one of the worst builds I've seen. Looks like it was passed around over the years to a few modelers, there's evidence of this.

My interest is if anyone knows of this Company?
Thanks,
B

The Eureka kits surfaced from Japan IIRC, in the 50s. Then they were mostly cherrywood, heavy but they flew and took punishment. Later on in the '70s there were still kits from there that were fantastic. At the 1971, maybe '72 NATS in Glenview, IL, there were two B-36es converted from CL to flying in RC Scale. Each had 6 K&B .19s in pusher fashion. At that time I owned a Hobby Shop in Mt. Prospect, IL. and I had a B-29 kit in there for a while. The fit of the precuts allowed us to assemble the main-structures and fit all together without glue or tape. THERE WAS NO laser stuff or even computer cutting back then. Definitely not the usual DIE-SMASHED American kit style. 

BTW, keep the washout if in both wings, and not horribly done. Washout is your friend, especially for a non-aerobatic model. Many an RCer would have his Scale model longer if he would simply adjust each aileron UP about 3-5 degrees. Works!

I set up a scratch built Hawker Sea Fury for profile scale and carrier several years ago and put the following items with these settings

          Motor - zero degrees, no up or down thrust
          Motor - Zero degrees ahead, no right thrust
          Wing - 2 degrees angle of attack relative to fuselage Center Line
          Stabalizer - Zero degrees angle of attack

The relationship between the wing and stablizer is important. I converted the Hanger Nine Cub (80") to CL back in 1996 and had to remove the stablizer angle of attack (Incidence) otherwise the model would fly tail high. Once I took the positive stabalizer angle of attack out, the fuselage was level with the ground during cruise.

You will also notice that some full size aircraft like the Grumman Wildcat show positive angle of attack (incidence) on the horizontal stablizer. A friend scratch built a Wildcat and put in the scale horizontal tail incidence and model would never trim out regardless of where we put the Center of Gravity. Once he took out the horizontal incidence and put it at zero degrees the model flew great.

Also look at the airfoil, stunt models have zero degrees angle of attack on the wing so that when they go inverted the wing is still at zero degrees angle of attack when inverted.

The ability of the model to do aerobatics is dependent upon the location of the Center of Gravity, the further forward the CG the less aerobatic the model. The further aft the C.G. is more aerobatic. But if you move the C.G. behind the aerodynamic center of the wing (which is fixed) the model will become unstable and unflyable. I start with my CG at the 25% mark (Average chord) and move it back until I get the response I am after.

You might be able to leave the wing angle of attack alone and still make it aerobatic. I have seen a C-45 do aerobatics at an airshow but forget if they did inverted flight for more than several seconds.

Good luck,
Fred Cronenwett

That is true, Charles.
Chris...

Fred,

Informative, thanks for that. Got photo of your models?

That stab incidence on "real" aircraft allows for slower landing speeds.

In some Utility aircraft, like the Beech 18 for example, STC's were issued for the decrease in the stab incidence. They opted for less drag and a greater airspeed.

I think?   

CB

CB:

I can't tell from the photo if Eureka was using a somewhat scale airfoil or not. I suspicion that they were not designing the model for stunt maneuvers, so I imagine that the airfoil is much like a Clark Y, or such. If that is the case, I would leave the washout in place. I can't remember the numbers exactly, but the real D-18 had like 4.8 degrees at the root and like 4 degrees at the tip. The tailfeathers were like 2 degrees negative. Got to remember that this airplane was designed for lifting, not fighting. Consequently the airfoil was monstrously thick at the root and narrowed down to an extremely narrow tip. None of those features would lend themselves to much in the way of stunt maneuvers in model form. Just my opinion, of course.

Jim Fruit

I have a B-25 that I got back in the early '70s.  It's maybe 50% done.  Almost can't read the "blueprints" anymore, I should ink them so that they survive.  Stopped on it when I figured I would add more scale surfaces to the kit and throttles......  Class A and B engines suggested (.19-.29).

Eureka was a system of "cottage" makers I understand and the name changed 3 or 4 times over the years.  IIRC, Kyosho was the same group.   Metal cowls, shock absorbing LG, etc., etc, but horrible decals! LOL!!

Big Bear

HC,

I was considering taking, not only the washout out, but also lowering the wing incidence. Enough so the model would do playful stunts.

UH OH! My Bad. Being an Eureka kit, I just thought Scale all the way. You never mentioned that so I simply assumed wrongfully. So Sorreeee!

Yes, most of those Japanese kits used a "Scale" incidence set-up. That was, IMO, a tad bit too much for good CL or RC  flying.

Jim,

Your retract gear for your great Beech? We have to talk about that?

So don't go anywhere.

OK, so you drew your own plans from the Pall Matt drawings, correct?

CB

CB:

The retract gear is Robart mechanicals. They activate from either front or back. I reversed mine and activate them from the front, over the top. In this particular model, the retracts raise reward, not overpowering a servo by centrifugal force.

Actually, I usually draw my own plans, but for this one I did not. I took dimensional information from Paul Matt drawings and drew the image directly on the wood. I occaisionally would make a template on some engineering paper that I have (divided into 1/4" squares).

JHF

CB:

Retracts rearward, per the original. My point about that is that there would be no centrifugal force resisting retraction or extension as there might be if the retracts acted spanwise. This sort of thing is the kind of important detail to consider at the time of selecting a subject to model. If the centrifugal force made it such that the servo could could not overcome it, that would be zero points, let alone a crash.

Half the wheel will show, it will be in the correct place. It was exposed on the original also. Landing gear covers retracted over the strut, but ended before the wheel, leaving it exposed.

Matts drawings show the radius of the rotation and also the tire size.

I think what might be confusing you is that the retract mount is below the wing to be in the proper pivot point. The nacelles are completed and in place now so all of that is hidden. The largest portion of the nacelles actually occurs below the wing. I am laying up the cowls now.

I forget the size of the retracts (here I go trying to remember again) but I believe they are for 6 to 7 pound airplanes.

I have been meaning to ask you, what is your "20" ? Mine is northeast Illinois, right on Lake Michigan just south of the Wisconsin line.

Jim Fruit

CB:

Don't need a new home, everything is paid off here. Wouldn't mind missing the winters though.

Robart 600 Mechanical Retracts, 2 to 5 pounds. Sounds rather light duty, but I think it will be OK in my plane, particularly when I fly only off of asphalt.

No particular talent needed to make fiberglass cowlings. Create a styrofoam form; resin and glass on the outside of that; sand,sand,sand; apply fillers if needed; hog out the styrofoam form; done.

Are you trying to apply heat while removing the Econocote?

JHF

JHF,

Just because I said you had talent, doesn't mean I'm without some. Glass I can do. It's the stuff, where you have to think, that I have trouble.   

I made this cowling that exact way. However, the talent I need is in finding the time to do it.

The Beech cowlings are tapered, am I correct? Not like a Corsair.

Ya know, I could send you FS, (full size) drawings of my cowlings. Feel like making a few more at the same time.

We could trade talents. I do do graphics. Do do, Well, I make graphics and paint masks.

Come to think of it, what will you do for insignias? Gotta sign guy in your Club?

Because of you, I'm going electric.
CB

CB:

Yes, the Beech cowlings are tapered. Mine are 4.1" at the back, 4.3" at the approximate center, and then french curve down to 2.6" at the front opening.

Sorry, but I will need to obligate full time to my Beech to be ready for next year's Nats. Won't have time for others.

I do my own graphics. Mostly with Frisket paper and spray paint.

Jim fruit

CB:

You are not a pest, it is great to have someone with similar interests.

My cowl diameter at the thickest point is 4.3". That is at 1" = 1' scale. Your scale is 1-1/8" = 1'. Using my dimension for comparison, your cowl maximum diameter should be 4.8" (4.3" x 1.125).

Yes, the same Robart number could retract forward, just turn the unit around. But why would you do that? the real airplane gear retracted backwards. The Robart unit can be operated from either end, just take the unit apart and run the push pin (or pull pin) out the other side. I reversed my push pin out the other side and run the actuation cable over the top of the unit to get all of that linkage away from the wheels.

Jim Fruit

CB:

You are right, there is eleven hundredths of an inch between our two interpretations. I doubt if the judges will be able to tell who is right from fifteen feet away. Why did you ask if you already had the answer? Was this a test?

Wow, tri-gear. I have seen one of those. That will solve a lot of issues with the taxi maneuver. Charlie Bauer says he won't build anything but tri-gear now for that purpose. With all of the options that I have available, I won't have to use taxi as one of them unless I want to. Now I understand why you asked about retracting forward.

It would be the same Robart unit if you are retracting forward (nacelles) or backward (nosewheel). You simply turn the unit around. There are lots of options available with the same unit.

JHF

Jim,

No not a test, just checking the accuracy of my drawing.

Here's a test question. What Robart gear are you using?

Hey! Did you consider electric retracts?

What's with the Rearwin Speedster. You have AADHD also? 

CB

CB:

Like I said before, I am using Robart 600 Mechanical retracts.

I have other air retracts in my shop, but I am trying to go light for this model.

Rearwin, I am always preparing for the next project. It can take so long to gather the appropriate detail, that one should not wait until he is ready to go to start looking for it. I have to finish the Beech, but there was a little dead time while I wait for the cowl resins to cure.

JHF

CB:

Photos scheduled in about a month when I have more done.

Over styrofoam, use polyester. Do NOT use epoxy.

JHF

CB:

Sorry for the delay, I did not realize that you had responded. I have nothing against epoxy, use it all the time. Many years ago, however, I created a styrofoam plug and applied epoxy then fiberglass. The styro wound up in a puddle on the floor. The epoxy had attacked it. At that time, I went to a blown glass to make my molds out of. But that stuff is mean to work with. I then learned that styro can be used with polyester resins being compatible.

I have also been told that with high heat (say on the hot asphalt) an epoxy can soften. I have read that the solution to that is to "preheat" the epoxy/fiberglass item to a temperature higher than it will experience during use. For example, put the item into a 200 degree oven for a while. Two things wrong with that: 1. Getting it past the wife (sort of like storing cyanoacrylate in her refrigerator). 2. Why go through the bother, just  use polyester resins.

JHF

Don't know what Epoxy you were using, but when I was playing with F2C we quit using Polyester resin as it would not set up stiff enough for us.   Went to using epoxy glues to do lay ups over foam with glass cloth with no problems.   The main problem was after removing the foam was the rough interior until we started finishing the exterior of the foam.   Now using K&B epoxy paint was a no no also, unlesss the foam had been sealed.

John:

Been a long time, but I think it might have been Hobbypoxy 2. I screw up everything that requires memory, however. Strange, I prefer the polyesters because, in my opinion, it sets up more stiffly. When I try to sand epoxy, it gums up my sandpaper. Polyester just dusts off. Maybe I am doing something wrong.

By the way, for the rough interior, try applying drywall compound to the exterior of the styro plug. Sand it off with a very fine sandpaper and then apply the fiberglass. That improves the interior smoothness.

Jim Fruit

Thanks Jim for the idea on sealing the foam.   I guess I didn't use enough hardener in the polyester resin.   It was the material I gave up on for finishing as it gummed up the sandpaper.   I have the epoxy resin that MECOA is now putting out that I am going to try.