Teenage Pilot 14

Alright, folks, I've finally developed a good, stable, reasonably fast delta-wing foam plane that's very simple to build and flies real nice. I call it the Weasel Jet. Mine has a not-really-extreme power system and it goes upwards of 75mph yet slows down and flies nice and calm for landing or relaxation. It's quite cheap to build, made of foam-core board from Dollar Tree (or any 3-6mm foamboard, Depron, etc.) and (optional) 0.5" insulation foam from Home Depot.

*I'll try to get pics up tomorrow but my camera is really a useless piece of junk so I can't gurantee anything.....*


Step 1: Cut out your wing.

Wingspan is 30"; it's easiest to build it from the Dollar Tree foamboard becasue the measurements all fit it perfectly. The wing should have an 11" root chord and the tips should be swept 2" back from the "v" in the trailing edge, creating a total wing chord of 13". The tips should be 4.5" from LE to TE.

It might sound a little confusing. I'll try some pics just for the general shape.

calvino

Sounds good there Beaver, maybe like a paint drawing may help, i need to make one now thanks to you

Teenage Pilot 14

Hmmmm.... tried to find Paint. It must have gone down the black hole. It's just not on my computer anymore....... Really weird.


Anywho, I'm thinking I'll try to get my sister to let me use her (really really nice) camera. It should sort smoe stuff out. For now....


Step 2: Stiffening the airframe/motor mounting.


To stiffen your wing, you can get away with one 26"-30"x1/8" carbon fiber rod or tube attached spanwise with glue. Depending on your power system choices/ design changes, you may want a lot more, perhaps even full fiberglass. My first one had the CF I mentioned but at 65+mph the whole plane would flutter badly, especially after a few hard landings. My newer one has a 24"x 3/8" CF arrow shaft glued/taped along the bottom of the wing. That wing don't budge an inch.

For a motor mount/fuse stiffener I use a 12.5"x10mm spruce stick, glued to the centerline on TOP of the wing with one end level with the front of the wing and the other end sticking off the back. NOTE: if you're planning on using a firewall-mounted motor, you may have to do some thinking and modifying to get it all together smoothly. I have no idea how one would go about that. ANOTHER NOTE: You'll need to add some downthrust (~2*) to the motor at the mount because otherwise the plane will nose up when you punch the throttle. You might have to fool with it a little depending on your power/CG/etc.




Step 3: Adding winglets/fins.

They may seem kind of useless but they add a TON of stability (like, rock-steady) and they're simple to make. Cut a 4.5"x7" rectangle sort of thing but swept back at a 75* angle. Glue this to the end of your wing with the edge of the fin on top of the wing so it doesn't stick to the building surface like mine did. Do it again on the other side.




Step 4: Fuselage


If you have some 0.5" or 1" foam on hand (any type will work) you should use that. If not, you'll have to cut lots of fuselages out of your foamboard and glue them all together.

Cut a shape you like (I use a smooth, curved airfoil-like shape) out of your foam and get it so it's nice and smooth/clean. Cut an indentation in it so that you can fit it onto your wood fuse stick and still have it flush against the bottom of the wing. Again, pics will clear it up. Now take the battery you want to use and mark out its size and shape on the side of your fuselage. Cut out this space. For batt holding I use Velcro glued to the top of my battery cutout. You can use a different method if you wish.

Now is the time to paint you FUSELAGE ONLY. NOT THE REST OF THE PLANE. JUST THE FUSELAGE.

After your paint is dry, glue some CF onto the front of you fuselage, extending as far back/forward as you can manage, to strengthen it. That's mandatory as you'll be putting lots of stress on this point.

Now, test-fit once more to make sure it's all straight and even, then glue it in place on the wood stick. Don't skimp on the glue here, got it?



Step 5: Elevons


My elevons are 2.25" chordwise, cut at a bit narrower at the prop's location to allow better airflow to the prop at high deflections. I use packing tape for hinge material because it's strong, light, and does the job well. I use Du-bro 1/2A control horns because they're the only ones my hobby shop has in the right size.



Step 6: Electronics/power

Ooooohhh, the juicy part. For onboards, I have a JR RS6UL rx, 2x JR SM15 servos (painfully slow but they work, and they're strong), an Electrifly SS 25A ESC, a 1300mAh 25C 3S lipo I got from Hobby City (>$20 with shipping for an amazing pack can't be beat), and a Suppo A2217-6 1500kV outrunner spinning a Zinger 7x7 wood prop. This setup works well, but the ESC is overworked (300W+) and it heats up a bit.

Servos are mounted by gluing them with lots of glue to the wing surface close to the fuselage but in line with the elevon. Make sure that your servo arm, pushrod, control horn, and elevon all follow the same arc. This will give you the most possible leverage and strength

You can use anything you have on hand, really, as this plane will fly well on about 100W as a slow flyer, or 500W as an (over-the-top) extreme speed thing. I reccommend strong servos as the elevons are pretty big and pulling out hard from a dive will hurt bad ones. Battery can be a simple 2S 1200mAh lipo up to a 4S 1500mah+. Just remember CG and such and don't go too crazy.





Final notes and stuff.........

Well, first test everything, make sure all works correctly. I've left a lot of variables for you to mess with so feel free to experiment.

Remember to keep your CG around 3.5"-4.5" back from the LE. Also, with really big motors/power systems, be mindful of prop torque roll.

When landing, go in smoothly with the nose up a bit, keep touchdown speeds as low as possible, and just drop the plane into the grass.

Don't crash.

Enjoy!!! I'll try to get some pics up now....

Teenage Pilot 14

A picture's worth a thousand word... and in this case, more like ten thousand. New advancements have been made in the Weasel Jet developement line, many have been incorporated into this version that I'm posting:

The pink one is the (very very similar) Beaver Jet, made out of 0.5" insulation foam. It's what your Weasel should look like.

Teenage Pilot 14

Also, regarding the differences in measurements, the DRAWING is correct on EVERYTHING. The previously posted dimensions should be used only if you want a little more wing area.

calvino

Nice work Beaver, mind if I try and make a PDF of it [8D]

Teenage Pilot 14

I don't care what you do with it but you have to build one And once you do that you'll have to join the Experimentation Program......

My chemistry teacher has a monstrous periodic table hanging on the wall, about 5'x8' and made of coroplast. I want to cut it into a huge Weasel, or maybe an army of normal ones. He's not too thrilled with the idea, though.....

I've got a present coming for myself: A brand-new 3S 30C 1300mAh lipo. Lots of 3's in that one. I'll be building yet another Weasel when it arrives or when I get more foam/CF/etc. I still haven't taken the control horns off the last one that fell victim to the tree (and killed my old lipo in the process )..... I'll probably be testing out the 2212-6 on 5.5x4.5 and 6x5.5 APC props on the next Weasel too. I was never able to find the right ones at the hobby shop until recently so that motor just sat there doing nothing. It's WAY more than enough to shove the little beast along.

Teenage Pilot 14

Ok, new battery came. I built a new Weasel. It's the best-flying one yet. I changed the elevons a little so as not to block the airflow to the prop; they're now 12" long.

I've got even more power on tap now (I'm at about 350W/lb[X(][X(]) and the plane will do anything I want it to. It's pretty aerobatic but stiffness leaves a lot to be desired. I'll have to work on that. I think I topped out around 75mph today on the maiden but it's so floppy I was afraid to push it much faster, though no flutter was evident. I think if it does that it'll be very sudden and just rip to pieces in an instant.

I used flat wooden spars to strengthen and stiffen it because CF is too pricey. I've also got pics this time but it's not letting me upload them. I'll keep working on it....

Teenage Pilot 14

Ok, the latest and greatest Weasel has been built. It uses two wooden spars across the bottom of the wing (1/8"x1/2" spars) for stiffness and it seems to be fairly strong. I tried with the stripped foam but it's just too soft. The newest one is regular papered foam from Dollar Tree with the old power system and a carbon spar on either side of the fuse for extra strength. The elevons are 12" from the tip of the wing by 2.25" wide. Weight is 14.1oz with battery. I haven't timed it yet for flight time but I've got a new/used computer radio with a timer so we shall see. At the farm on Saturday I was going easily 85mph (covering 100yds in about 2.5 seconds) but my ESC had problems so I couldn't really fly it a lot

I tried the floppy, stripped-foam one with a Suppo 2200kV motor and APC-E 6x5.5 prop. Fast but not enough thrust for my liking so for now it's the 1500kV and 7x7 woodie.

I've got two HK SS-25A ESCs on the way but I think my soldering job will hold on the other ESC.

As usual, I highly reccommend building one of these. It's a great flyer and it has potential to be a really crazy plane with more power and smaller elevons.....

Teenage Pilot 14

Awwwww, man. RCU isn't really the fastest-moving site ever, eh? I haven't been here for like 3 months and this thread is the first one on Page 2? Not enough action.... Well, let's see if I can't get someone to build this thing.

Updates, updates, updates..... New updates from Beaver Labs on the Weasel Jet

First, I ditched the profile fuse in favor of a full-fuse design that holds everything inside (except the ESC, which stays out for cooling). It's faster..... I also propped down to a 7x6 and it's getting an easy 100mph. That's the fastest Weasel Jet in the world, provided no one has built one yet. I covered 320' in exactly 2 seconds going into a very slight breeze, so I generaly put he top speed around 105mph in level flight, probably up to 130mph in a sharp, full-throttle dive. I've got actual tiled PDF plans to print out and use to cut your own. I'll post those here soon. I have pics, too, but no word on when I'll be able to get them off the camera and on the computer.

The other big thing in the Weasel family is also the smallest. I built a 2/3-scale (20") version and loaded it up with an Arc 110 3100kV inrunner, 4.5x4.5 prop, Electrifly 910mAh 3S lipo, and a HK 25A ESC. This thing rips! It's doing a bare minimum of 85mph and since the 100%-eff. pitchspeed is 146mph it's probably over 90 or even 100mph, which puts it on par with the normal-size one. It's 9.2oz AUW really became noticeable when I landed it but in flight it floats like a butterfly, stings like a bee I maidened it yesterday and flew for 20 seconds before the cold forced me to go home (since I'm 15 and have to bike to and from the field my ability to stay out there is greatly diminished).

Again, this is Beaver Labs with a Weasel Jet report.

That's all.