Curare Build
 

Winter build of a Curare kit from Eureka. My plan so far is to use a Rossi .60 Blackhead and mechanical retracts. I hope to be finished in the spring. My plan is to be as faithful to the classic as I can be, with a fiberglass and paint finish.

RE: Curare Build
 

Mitch,

looking forward to your new winter build. Started yet?

David.

RE: Curare Build
 

Hi David

Yep, she's on the board. Currently glueing in the fuse doublers.

Looking forward to staying motivated with your help.

I'm very happy with the quality of the Eureka kit.

Mitch

RE: Curare Build
 

I too am interested in building a Curare and will be watching your progress. I think I'd like to build mine with foam wing and stab but undecided. What led you to pick the foam version. Thanks for sharing.

RE: Curare Build
 

I had one more bottle of Southern's Sorghum left!:D

Seriously though, I want to get this done before spring, and with the amount of time I am planning on spending on the finish, I wanted to expedite the build.

RE: Curare Build
 

Progress is slow until the holiday vacation. Stab is sheeted (still rough). Fuse sides are started. I am in process on engine and landing gear installation planning. I made a scale drawing of the firewall in CAD to plan the details of the engine mount and nutplates install.

I still need to pick a tank and finalize my engine plans, I am having second thoughts about the Rossi. I am trying to rebuild it with new bearings, but I can't get the fool thing apart. The piston liner is currently stuck halway out. I heated the case to 300 degrees and pushed a piece of plastic into the exhaust port from the top and turned the crank (with a prop hastily bolted on). That worked, but only as far as the piston will push it. Any suggestions?

RE: Curare Build
 

Mitch,

This is awesome. You are doing a build thread on one of my favorite pattern planes. I'll be watching your build thread with keen interest. Since, building classic pattern planes is new to me, hopefully I'll pick up a few tips and tricks along the way....:D

Thanks for taking time to do the build thread.

David

RE: Curare Build
 

David,

Thanks for the interest. I'm hoping to learn a thing or two in this process myself!

Mitch

RE: Curare Build
 

Mitch,

are those B&D retracts? If so, I'll be curious to see CU's of their installation and operation. Curious to see the difference with other mechanicals.

David.

RE: Curare Build
 

David,

I'm not sure who manufactures them, but the packaging is Hobbico. I'll be sure to take closeups of the installation. I'm planning that now.


Mitch

RE: Curare Build
 

Excellent.

Check out the Hayes tanks - you might like them. They have a low profile tank that might help with the nose gear up front. Here's what I'm thinking:

http://www3.towerhobbies.com/cgi-bin...&I=LXK836&P=ML

What are your other engine options?

David.

RE: Curare Build
 

David,

The nose on this bird is so narrow that it is causing me problems with using a standard fuel tank and engine mount. The firewall is about 2 inches wide. Here's what I have so far:

As for the engine, I am going to mount a brand new OS .61 FX. I will leave provisions to swap out the Rossi when I get it sorted out.

Also included in this shot is a closeup of the nose gear (not in the correct position, I know).

Mitch

RE: Curare Build
 

engine fitting:

RE: Curare Build
 

Nosegear looks like it's going to be awfully short to be able to fit!

RE: Curare Build
 

Ground clearance looks marginal but OK. Zip-tie is ground level.

RE: Curare Build
 

Wow... that is pretty narrow! Then again, I remember identical concerns in my Tipo planning and builds which are essentially not much different from the Curare nose.

But actually it looks pretty good. It appears that your tank (it must be a 12 ouncer which is actually what the MK plans call for - 360cc) will leave the rear portion of the tank area open so you'll be able to tuck the wheel in there behind the tank. The nose gear always looks short but if you measure the farthest distance to the LE of the wing you should have the length shown on the plans when the gear is extended. That's all you should need.

I see that you have a prop mounted on your FX and there seems to be ample clearance. Is that an 11" or 12" prop?

I also assume that the tank fits through F3 which is where it will have to be slid into position through unless the opening between gear opening side blocks is wide enough to pass the tank. I'd try to insure you can slide it though F3 so that you can fix the tank floor into position. You might need (want) to make a U shaped cutout in the rear center portion of the tank floor to provide clearance for the wheel as well as to facilitate the linkage back to the servo which might best be mounted directly behind F3. The only problem with servos directly behind F3 is making sure that you can still remove the tank without the servo interfering and thus require to be removed as well.

I remember going through the acrobatics of getting the tank/gear/servos/linkage sorted out in the little Deception [&:]. At that size it was even more fun!

In any case, that looks like a good tank for the application. Is it possible to mount it sideways to leave even more space between the tank floor and the fuse bottom? It would have to be ~2" wide or so if I understand correctly.

David.

RE: Curare Build
 

Mitch,

may I suggest that you make the bottom of the plan ground level (as shown). It might require a notch in the center portion of your wing LE but I would do it. What is the spacing going into F3 for the wing LE dowels? That's how wide you can make your notch. You should have an inch there to work with - it's all you need provided your wheel is centered on the fuse C/L (i.e., gear mount is probably offset from C/L)

David.

RE: Curare Build
 

The other reason the fuses need to be narrow at the FW is so that it will allow a header (muffler? :eek:) to be attached to the exhaust of the engine. On a Curare you will likely need a big drop in the header to bring the pipe down parallel to the fuse under the wing. Luckily, they are probably the most common headers at Mac's. [8D]

David.

RE: Curare Build
 

David,

The prop is a 12 inch Master Airscrew that I happened to have handy which is the largest dia. that I plan to run. I'll most likely run with an APC though.

The tank was chosen because it fits through the hole in F3 (with a little persuasion). I didn't want to get creative and come in from the top or bottom. The tank is taller than it is wide, and so it can't be mounted sideways.

I like the idea of notching the tank floor to allow the nosewheel to clear. Thanks! I'm not so wild about the idea of notching the wing leading edge. I'd rather just run with marginal ground clearance. I've already resigned myself to flying this one off of asphalt only.

For clarification, the distance between the insides of the fuselage sides at the firewall is 2 inches (if that makes more sense). The tank's cross section is rectangular and the narrow dimension is just under 2 inches, so it barely fits as shown.

Mitch

RE: Curare Build
 

If the interference is still too great to pull the liner out you can reduce it further by making the liner cold and the case hot. Try cold soaking the engine in the freezer a couple of hours. Then heat the outer barrel with a flame while pulling on the liner. A gas stove works well. Just try not to heat the liner and work quickly. It should slide right out. I don't own Rossi's but I have successfully removed stubborn liners from other brands doing this.

RE: Curare Build
 

Interesting...

what does that do to the integrity of the alloys? Not that I've been there but I'd imagine one could potentially start having fissures in the metal matrix (liner or case) - but maybe they are more robust to abrupt temperature changes than I'd imagine.

I admit that I still have a liner stuck in a YS AR that I haven't tended to...

David.

RE: Curare Build
 

Mitch,

sounds like you are way ahead of my thoughts. I just assumed you might be able to fit the tank in sideways once in the compartment - 2" is narrow!

The mounting lugs on vintage Rossi's and OS SF's are so close that you can use the same mount. I'm not sure if the FX changed that spacing from the SF but if not, you should be able to swap out the engine to hearts content. Otherwise, it would be simple enough I suppose to use another pair of glass mounts like those you're using (Sig?)

Looking forward to seeing the frame-up.

David.

RE: Curare Build
 

The aluminum alloys used in cases are quite ductile so local temperature gradients aren't a concern. One potential threat is reduced temper in the case alloy but one would have to get the aluminum very hot (500+ F) for that to occur. You just warm the barrel of the crankcase evenly until the liner slides out. It shouldn't require much. The idea is to have the liner at 40F and the case at 200F. With that temperature differential the heat will transfer to the liner very quickly so work fast or you'll have to start all over. This technique has been used for generations of automotive engine rebuilders to remove stubborn crank pins from aluminum pistons. It's where I acquired it.

When replacing the new liner cold soak it in the freezer and heat soak the case in the oven at 250 and they should go together without fuss.

RE: Curare Build
 

Well, good to know. My concerns are appeased. Maybe I'll manage to get that YS liner out of it's case now.

David.

RE: Curare Build
 

Hello, I noticed the canopy in your pics,can you confirm that the Eueka short kit comes with a canopy please?