Aloha EF-1 design and build

[Red]

Hey gang,

I used to be quite active in pylon and R/C in general. A new job and a move of the family slowed my drive down quite a bit. I still build and fly, just not as prolific as I used to be. Anyway a freind talked me out of retirement and into racing EF-1 again at Winterfest in Arizon in January. The last one that was in development that I never quite finished was Aloha. It is an OR-71 Owl. I was lucky enough to watch this one race at Reno when I was a kid.

I'm picking up where I left off with the Owl. It was very close to being ready, just needed a cowl and canopy. The yellow one in the picture below is the one I built 6-7 years ago. I ended up giving it to the same friend who convinced me to race again before I moved away. The one in the bones in the one I am working on now. A little more work on the wing and its ready to final sand and cover. Cowl and canopy molds are in progress. I 3D printed a cowl to see the shape. I've made a few tweaks and am ready to CNC cut the plug, then I will pull the mold from that. Same for the canopy when the drawing is ready.

It uses my typical laser cut jig-locking fuselage construction with a sheeted foam wing. My friend Archie (Iceman67) and I had an airfoil development program, this one uses the latest generation of that series. I'm anxious to fly it and see how it performs. Any questions, just ask.


Enjoy!
Red

[mcdracing]

Looking good!

[Red]

One mold half complete......

[Red]

Got the wing and tail covered but I have to stop here. I left my landing gear at work and I want to cover the the fuselage with them in place. Total weight so far less landing gear and fiberglass parts is 17.2 oz. including 12 blind nuts, pushrod tunes and torque rods. I’m pretty happy with that.

Canopy mold in progress.

Red

[Red]

I have both canopy plugs machined now. I’ll need to prime and wet sand, then I’ll be able to pull molds from them. I was able to finish up the rest of the covering. So as soon as I get the glass parts ready, it’s just down to final assembly.

Anybody interested in this?

Red

EDIT: I don't know why some of the pictures display upside down, but if you click them they open correctly.

[KRProton]

I just saw your post. Beautiful subject. I'm not familiar with the Owl. I like the outlines and seems like a relatively high aspect ratio wing. It's beautiful as appears to be your work and especially the molds!

I've kind of set EF1 aside just to reduce my expenses a little and simplify my racing weekends, but I look forward to reading more here as you progress!

Tim Lampe

[gsjames]

I always thought that the OR-70-1(Fang) and OR-71-1&2 (Lil' Quickie/Aloha/Wise Owl) would be ideal candidates for an EF-1 because of the annular air inlet that George Owl incorporated into the design. Many of the ARF's have cutouts in the cheek cowls, which is useless drag because the motor is not there. An annular inlet (and the Cheetah spinner) blow cooling air directly on the hot motor. Good work, Red!

[Red]

I just saw your post. Beautiful subject. I'm not familiar with the Owl. I like the outlines and seems like a relatively high aspect ratio wing. It's beautiful as appears to be your work and especially the molds!

I've kind of set EF1 aside just to reduce my expenses a little and simplify my racing weekends, but I look forward to reading more here as you progress!

Tim Lampe

Thanks Tim. For whatever reason the Owls sort of faded away. I heard they were a little tedious to build, I’m sure that had something to do with it. Alley Cat flown by Ray Cote and eventually Jason Somes was probably the best known Owl. Aloha eventually became Alley Cat.

Red

[Red]

I always thought that the OR-70-1(Fang) and OR-71-1&2 (Lil' Quickie/Aloha/Wise Owl) would be ideal candidates for an EF-1 because of the annular air inlet that George Owl incorporated into the design. Many of the ARF's have cutouts in the cheek cowls, which is useless drag because the motor is not there. An annular inlet (and the Cheetah spinner) blow cooling air directly on the hot motor. Good work, Red!

Gary,

I’ve always liked the shape of the Owls. This one is designed around a 1.75” spinner, with the idea that the annular inlet could be used with a 1.5” spinner if you wanted.

Red

Red

[gsjames]

I’ve always liked the shape of the Owls. This one is designed around a 1.75” spinner, with the idea that the annular inlet could be used with a 1.5” spinner if you wanted.

Red

Good idea!

[Fly Fast n Left]

The model is looking very nice! What material are you using on the molds for the cowling and canopy?

[Red]

The model is looking very nice! What material are you using on the molds for the cowling and canopy?

Its a 40lb urethane tooling board. I was lucky enough to have a couple scraps left over from another project.

Red

[twitte]

I always thought that the OR-70-1(Fang) and OR-71-1&2 (Lil' Quickie/Aloha/Wise Owl) would be ideal candidates for an EF-1 because of the annular air inlet that George Owl incorporated into the design. Many of the ARF's have cutouts in the cheek cowls, which is useless drag because the motor is not there. An annular inlet (and the Cheetah spinner) blow cooling air directly on the hot motor. Good work, Red!

Gary,

I’ve always liked the shape of the Owls. This one is designed around a 1.75” spinner, with the idea that the annular inlet could be used with a 1.5” spinner if you wanted.

Red

Red

Red,

Do you have an outlet planned in the fuse or just a open space cut in the covering?

Trey

[Red]

Trey,

I plan to take air in annularly or with slits in the cowl. I use “ears” behind the slits to direct air over the motor and also to mount the cowl. From there, I enclose the motor box with covering and that forces the air through a hole in the lower firewall and out a hole on the lower fuselage between the gear.

Red

[Red]

I’m still waiting on my mold sealer order, so not much happening there. In the meantime I was able to work on some of the graphics using the pictures I posted earlier. The software I have that came with my EBay cutter has a trace function. So messing with cropping the photo in Paint and using the trace command, I was able to get reasonable results.

Red