Willy Nillies Eaglet 250 Build

[speedbirdted]

Now is the time that I pull the trigger and build one of these! And the box showed up today so I guess I can't put it off any longer...

This is what I got in the kit. First impressions are WOW the laser cutting is very well done here. Seems like most laser cut kits I run across were either cut slightly misfocused of with too much/too little power, and neither of those conditions shows up here. Everything looks and feels like it'll come out with minimal effort and that's what I like to happen!

It's also not common that I start a build already having everything I need to finish it besides the kit (besides batteries - but those are still in transit) and this is what I'm going to use. The motor is a 1510 and it's probably going to be massively overkill running off of a 12 amp unbranded Banggood-esque speed controller, but hey this is what I had and it'll just make the takeoffs shorter. On a 6x3 the motor easily makes 300g thrust so this should be fun! I also bought one of the receivers they had in stock at Willy Nillies because I didn't have one that would fit. Initially upon seeing it I was concerned because Redcon makes a very similar receiver that is sold on Banggood and I've had bad experiences with them, namely I bought four and three refused to bind. Luckily the one I ordered with the kit worked perfectly.

I also bought some 1.25" wheels. Though I have some 1" wheels on hand as well if those end up looking weird, but I think they'll be fine.

You may wonder why I have 5 servos. Well...

Most of the Eaglets that I've seen built so far have been fairly standard. Nothing wrong with that! But - now that it's been proven to be a very good flying airplane by several independent people I think it's time to get a bit creative and build something more unique.

So I'm going to be doing some alterations to the kit -

• Taildragger. Don't have anything against tri gear planes, sure the ground handling is great, but I think this plane would do pretty well with a taildragger setup. It would also cut a little bit of weight out, no big nosewheel. I think I'm going to just use a tail skid, since getting an actual tailwheel to work while this tiny would be torture and I don't want to add any more tail weight than I have to. Hopefully the heavier motor will maintain balance even with no nosewheel, helped by having the main gear moved forward. A taildragger setup also helps my next mod, which is...
• Swappable gear. I am going to build floats for this thing (and claim the first floaty Eaglet because I don't think anyone else has done it?) simply because I flew a UMX Timber off of water and was instantly in love with it, and that plane is about the same size and weight. This will require a little bit of fuselage modification and if I do it right hopefully it won't result in any noticeable weight gain or cg changes. My idea is add a tab setup for the wheels and forward mounting for the floats and then adding a tiny little ply hardpoint where the rear float mounts go, and using a couple of screws to hold those on. The tab in the forward fuselage will either be retained with neodymium magnets or a servo arm acting as a latch. Whichever is lighter and works better.
• Flaps! This is why I have the extra servo. I honestly have a hell of a lot of work to do to figure out how to implement this and do a good job. And before you scream at me about flaperons, I know, and sure I could use them and save myself some headache but separate flaps are a lot cooler. That and from my experiences flaperons make your roll authority kind of disappear, and that is generally considered suboptimal. The way I want to do it is have the aileron servos placed farther out in the wings which will probably require either modifications to the existing ribs or cutting a couple of my own ribs, both of which I can live with. This is to both free up space in the center section of the wing and also move the servos to where the ailerons actually are on the outer portion of the wing instead of them being the whole trailing edge. Emptying the center section of the wing of servos now allows me to install the fifth servo in either one of the spots where the aileron servos are originally supposed to be, or in the center of the wing directly above the fuselage. The first option requires just a simple torque rod to control both flaps at once and is pretty easy to implement as I could just run the torque rod through a brass tube embedded in the trailing edge. The second option requires the control horn to be on the torque rod - harder but still doable, and it removes the visual and physical imbalance that comes from mounting a servo on one side without countering it with a second one. I still have a lot to work out and a lot of studying the kit to do, so I might end up doing something entirely different or if I determine that it would be too heavy and impractical I might skip over this entirely.
• Leading edge sheeting. Not sure if I'll do this one or not - it would require shaving down every single wing rib, and while doable it's quite tedious. Especially considering the only reasons I really want to do it is to experiment with mounting VGs on the wing to play around with. The benefit of helping the airfoil maintain its shape has been shown to not matter as I don't think anyone that has built an Eaglet thus far has done this. why'd I think of this?

A quick question to anyone who has built one of these - what glue did you use? I'm heavily leaning towards using cyano as it's lightest and by far the nicest to work with on this scale, but I don't know, maybe someone tried something I missed and it ended up working out!

Stay tuned. I'm currently in the process of moving house, so there's no chance I'll get this entirely finished in the space of 10 days like I did the Gentle Lady, and don't be surprised if it falls off page 1 for a while at a time...

 

[vhandon]

I prefer tail draggers myself so I think that mod is cool. The flaps will be a challenge but will be fun if they are effective. I used thin CA for the entire build of my GLH-250 and will use it again for the Mustang when it arrives.

 

[Turbojoe]

First and foremost: You'll LOVE the Eaglet! If I can make some suggestions as an Eaglet 250 builder forget about Flaps: It seriously doesn't need them and they'll just be added weight and frustration. Tail dragger: If you're going to do it use a tail wheel. I found out after several minutes of fighting ground loops with my Super Sport maiden that a tail skid just doesn't cut it. I'll add a tail wheel (or maybe nose gear) to that plane before it flys again. Leading edge sheeting: again not needed and excess weight added. I bought two Eaglet kits expecting to do massive changes to the second one. That second kit is still in the bag as the first one fulfilled all my expectations. The only major change I did to the first build was steerable nose gear. The file for my under 2 gram nose gear design is on Thingiverse if you have a 3D printer and want to print it out.

Joe

 

[Turbojoe]

As far as glue I used a combination of thin CA and my all time favorite Super 'Phatic. LINK The Super 'Phatic seems expensive at first glance but a little goes a LONG way and a big plus is that it sands really well unlike hardened CA.

Joe

 

[speedbirdted]

Yeah I didn't even think the sheeting would even help that much aside from having something to mount VGs to and upon thinking about it more I don't think they'll do a whole lot, so that idea goes in the trash. I'll admit part of me wanting the flaps is they also look really cool. Like I said I'm gonna do some serious inspection of the wing so I can do it in a frustration-free manner and there's the possibility it gets thrown out altogether I know it will add just a tiny bit of extra weight - but hopefully that should be more than countered by the motor I'm putting on it.

How does one do a tailwheel this small?

 

[Turbojoe]

Yeah I didn't even think the sheeting would even help that much aside from having something to mount VGs to and upon thinking about it more I don't think they'll do a whole lot, so that idea goes in the trash. I'll admit part of me wanting the flaps is they also look really cool. Like I said I'm gonna do some serious inspection of the wing so I can do it in a frustration-free manner and there's the possibility it gets thrown out altogether

How does one do a tailwheel this small?

Bending up a tail wheel wire is easy. Providing room for it is another thing. You're going to have to make a hole through the H-stab right at the rudder hinge point. It can be done but it's going to be tricky at this small size. Just remember that you also have to move the main gear forward of the CG as well. You'll be changing the weight distribution and balance of the aircraft when you do all of this. Not trying to talk you out of it. It's just going to take some forward thinking is all.

Joe

 

[speedbirdted]

Well, obviously the main gear can't stay where it is in its stock position. That would make it a nosedragger instead of a taildragger

 

[TooJung2Die]

A quick question to anyone who has built one of these - what glue did you use?

Thin CA glue everywhere except for epoxy on the landing gear wire mounts. If you want to save some weight forego the shear webs. I don't think they're needed on this light weight airplane.

 

[Born2bwire]

I used Titebond II (similar to Super Phatic) for almost everything. I used thin CA for the wingtips, the trailing edge webs, and to tack the stabilizers in place for gluing. I used thick CA for the landing gear wire.

 

[Willy Nillies]

Great! Another Eaglet getting it's wings for everyone to see! I built tail dragger Eaglet 50 before. Looked really good that way. Put some big wheels on it with your flaps and have a Bush Eaglet 250!

Dubro make a neat little tail wheel assembly, we stock them can't remember the part number off the top of my head right now. Could always just "Y" off the rudder pushrod near the tail, one y goes to rudder other to tailwheel.

As for glue, we use thin CA on everything with except for Medium CA on the Firewall, landing gear plate/wires, and joining the wing halves. Has worked out pretty well for us. Nothing wrong with the others suggestions at all. Sometimes it's nice to use slower drying glue so the build doesn't go so fast. ;-)

Keep us posted!

Doug and Becky
WillyNillies.com

 

[speedbirdted]

Forward fuselage parts all cut out and dry fitted. The finish of this kit is impressive. Not many kits I've built hold themselves together this well with no adhesives used whatsoever!

You can also see my idea for the slot for landing gear. This is not by any means the final design for it so that's why it looks ridiculous. I will use 1/16 balsa as the walls of the slot, though I'm going to add some small balsa gussets to reinforce it. I think there's supposed to be a hatch at the bottom which runs all the way to the underside of the servo tray - my idea is to either hold the landing gear in using this hatch, or split the hatch and glue on the back half under the servo tray while adding a ply hardpoint to the rear half of the slot so I can run a screw into it and use a servo horn to hold the hatch closed and gear in. I will also be adding small 1/16 ply hardpoints on the underside of the servo tray for something for the servo mounting screws to grab onto since I hate gluing servos into things - sure to start with it's less effort but what are you supposed to do in the situation that your servo craps out? I'm also going to add a hardpoint to the rear former to mount the rear float support onto.

 

[Willy Nillies]

There are two rectangular plywood pieces that are meant to be used as servo rails.

For the main landing gear mount, just cut the tabs off the existing mount and slide it forward to right at or just slightly behind the wing leading edge and do the bottom sheeting hatch like you said.

Sincerely,
Doug and Becky
WillyNillies.com

 

[speedbirdted]

There are two rectangular plywood pieces that are meant to be used as servo rails.

For the main landing gear mount, just cut the tabs off the existing mount and slide it forward to right at or just slightly behind the wing leading edge and do the bottom sheeting hatch like you said.

Sincerely,
Doug and Becky
WillyNillies.com

Oh! I didn't see those. You guys are ahead of me! I might do that for the landing gear - though I'll have to make a second wall anyway, and something for the underside stringers to be supported by (if they're supposed to go onto there)

 

[Turbojoe]

I'm also going to add a hardpoint to the rear former to mount the rear float support onto.

I can't wait to see her on floats! That'll be the coolest modification yet!

Laser cut float kits would make a nice option.

Joe

 

[speedbirdted]

It stood up!

I ended up taking Turbojoe's advice and put a steerable tailwheel on it instead of a tailskid. I feel like I'm really pushing it as for the amount of weight I'm sticking on the tail of this bird. I think I will end up also making a different (shorter) tailwheel wire out of something a little springier than just music wire. The wire actually runs through one of the plastic pushrod housings in the Dubro kit that I used - I was originally going to use a tiny brass tube but remembered that the pushrod housings are made to literally have as little friction as possible. Plus CA sucks at sticking to anything metallic. True, I could have used epoxy but epoxy is heavy and heaviness is bad for planes...

This setup, in order to get steerage off of the rudder itself (because routing a third pushrod to the back of the plane is a terrible idea) necessitates moving the rudder and vertical stabilizer fin back about 3/4 of an inch so the hinges for the elevator and rudder line up. I will not be splitting the elevator. The tailwheel wire would require a 90 degree bend at the top which I haven't added yet, because I want to be able to pull the wire back out for construction purposes (and maybe make a new one if I decide the current one is too crappy)

Here's my servo tray. The brace is there because bowden cables aren't actually useful if you don't affix both ends of them to something. It looks kind of thick but I used ridiculously light contest grade 1/8 balsa I had lying around. I tried 1/16 before that but it was way too flimsy.

 

[Turbojoe]

Looking good! Your idea of moving the vertical fin/rudder back is probably the best plan. You can go a lot smaller on the tail wheel. .032 wire would be light and flexible and transfer almost no shock to the mounting.

I'm a glutton for punishment and make it so much harder on myself by converting from tail dragger to trike gear but you're going to have a real nice tail dragger setup. Mount everything you can as far forward as you can as that tiny amount of added weight back there is going to need a lot of weight at the nose to counter it.

Joe

 

[Turbojoe]

Just a thought.....For the tail wheel wire bushing would a small nylon hinge half work? That way you can slot the end of the fuse and securely glue it from the inside. No chance of it pulling off.

Joe

 

[speedbirdted]

I'm going to try and find a smaller wheel. The reason it has that one is because it was just the smallest one I had at the moment...

 

[speedbirdted]

Had a little bit of free time to work on the Eaglet today. Underside bits are all done, landing gear slot is in and braced as it should be with 1/16 ply pieces. The round bit on the rear brace is where the latch screws into. I'm going to buck the trend of using the underside compartment for the battery, and instead put the receiver and ESC there: I don't know who it was that also added a hatch on the topside where the windshield is, but I'm going to do that because my batteries are narrow enough that they fit in that little compartment perfectly with no velcro whatsoever. I might put a little bit of foam in the front to protect the battery (the kind of foam you wrap your fuel tanks and receiver stuff in.) I don't know about you but having access to the battery from the top side seems much more practical. I might cut a few small holes in the firewall and a couple of holes in the fuselage sides to allow cooling airflow though the bottom compartment for the ESC. Perhaps the general openness of the interior will let me put the exit holes somewhere more inconspicuous...

The float mounts are also in place. They're mounted onto 1/8 balsa blocks soaked in thin CA to stiffen them up and use 1.6mm bolts with the corresponding claw nuts epoxied into the balsa. I put the sheeting on under the servo tray right after this picture was taken (and made sure to draw an X on the balsa to know where to drill the hole for the latch to make sure it hits the plywood )

I also added another purely aesthetic touch... and before you ask yes I did make two of them

 

[TooJung2Die]

Sexy wheel pants! I need to see the other side and how you mount them to the wire. Didn't you get an electric motor firewall with air holes in it?

Turbojoe and I both made top hatches for our Eaglets.

Jon