How to Build the Stevens Aero Puddlebug - A Build Log for a Laser Cut Balsa Radio Control Plane
Radio Controlled Plane Build
My son and I love flying RC airplanes. We live in an urban area and typically choose ultra micro scale planes that we can fly in a small park early in the morning. I don't like flying when there are people (especially kids) around - it just doesn't seem worth the risk if there is a mechanical or operator malfunction!
Our favorite plane so far is the. This three channel plane is super light and it is virtually impossible to gain enough momentum to actually cause much damage. Goodness knows that we have tried though! Hobbyzone Champ
As the weather got colder and wetter, I wanted to find a fun project to build with him. I looked long and hard on the internet for a reputable RC kit manufacturer and finally found Stevens Aero. There full details are located in the box at the end of the article.
We debated for several days about which model to build, but finally decided on the Puddlebug, mainly because of its small size and the fact that it uses the same electronics as the Champ! That meant that any spare parts we build up would be interchangeable.
This adorable little plane is made primarily of balsa, a super-light wood that is very common in the model building industry. If there ever is damage to it, it should be fairly easy to repair.
- Length 10.5 inches
- Wingspan 17.75 inches
- Wing Area 71 inches2
- Flying Weight 1.1 oz.
Flying it in a gym
You will need the following electronic components to finish the project.
- Spektrum DX5e, 6i or higher transmitter
- ParkZone [PKZ3351] or Spektrum [AR6400] Ultra Micro Receiver/ESC/Servo System.
- ParkZone Motor and Gearbox [PKZ3624] (Same motor as used in the Sukhoi and UM P-51)
- ParkZone UM P-51 Propeller [PKZ3601] or E-Flite* 4-Site Propeller [EFL9051]
- ParkZone [PKZ1035] or E-Flite [EFLB1201S] 110-120mAh 3.7V LiPo Battery
Gluing the Balsa Together
I am not going to spend a lot of time on this phase. It is easy to do and the instructions are very good. The balsa is laser cut and unbelievably precise. In fact, there was only one small notch that was too big to fit into the corresponding hole, but a quick trim with the utility knife fixed that.
All the parts are bonded together with a medium thickness CA glue. I used an accelerant as well, but it is not required.
Note: Do yourself a favor and go S-L-O-W-L-Y !! I rushed through too much of the construction and wasn't as neat with the glue as I should have been. The plane is not finished with paint or film on the fuselage so my glue mistakes are quite visible!
RC Plane Choices
What type of RC Plane do you enjoy the most?
Installing the Electronics
This cute plane runs on Parkzone DSM2 electronics. That makes it easy to find replacement parts if anything breaks. Many of you probably have spares sitting around the house from other builds.
The motor mounts easily with a drop or two of CA glue, but you do need to cut the four plastic spikes off of the assembly. Those are meant for securing the motor in a foam plane, but they won't penetrate the balsa. Cutting them off and securing it with glue works just as well. Make sure the motor is aligned straight - you don't want the plan flying in one big circle because of side thrust generated from a crooked installation.
The circuit board is attached using a piece of double sided servo tape. The push rods that connect the on-board servos to the hinged rudder and elevator are fairly simple to attach by bending the two ends at precisely the right length. If the push rods are too long or too short, the rudder and elevator will have difficulty finding "center" and keeping it there. Spend the extra time now to get it right.
Tip: If you prefer, you can create a Z-bend and an L-bend out of two pieces of scrap pushrod material. I found it easier to connect the pushrod to the servo and the control surfaces by connecting the pieces using a dab of CA glue and some heat shrink tubing.
Adding the Film to the Wings
The instructions that come with the Puddlebug include a template for the film that covers the wing. The film is either Parklite, Aerolite or Solite (basically a VERY light translucent film that is heat-shrunk on to the balsa wing and horizontal stabilizer.
The process is different depending on the brand of film you use, so read your manufacturer's instructions carefully.
The important thing to note here is to only cover the top surface of the wing and tail. Do NOT apply the film to the undersides.
Note: This was my first attempt at adhering the film to the surface of the balsa. The first material I used did not stick well to the balsa at all. I have no idea why. I bought Parklite in order to try a different brand and it worked extremely well! I had no problems, even though this was my first plan I covered.
I used a sharp razor to cut the material after it was adhered to the wood and gently peeled it away to reveal the exposed wood. I kept the tail in blue and the wing in orange - fun colors!
Tape the Rudder and Elevator
The hinging mechanism couldn't be easier. Simply use pieces of hinge tape. . .That's it.
I only used a few tabs of the tape for each surface (on both sides.) I was fearful that a full length piece of tape on both sides of the rudder and elevator would be too stiff and cause the servos to struggle too hard to move them. I am overly cautious, but my application did not seem to reduce the strength of the joint at all.
The instructions do call for sanding the edges of the balsa that will about each other into a "V" pattern to allow for the full movement of the control surface. It took less than 30 seconds to do it using the sanding block that came with the kit.
There is a large, inflatable tire that is the predominant feature of the front of the plane. It is held in place with an axle that is snugly held between the two reinforced brackets on the lower part of the body.
A thin piece of wire is bent using the template provided and slips in the brackets on the main wing. The ends of the wire then slip into the axle which holds the wing to the body and keeps the axle in place. This was pretty ingenious. It makes it very easy to pull the wires out to access the components.
The biggest warning here is to NOT use your mouth to pressurize it. The manufacturer states that the moisture will degrade the rubber and shorten the life of the tire.
Assembling, Binding and Flying
The ESC/receiver, motor, propellor and battery install very easily. Follow the instructions for placement and you won't have trouble. I used a foam tape to place the receiver and it works very well.
Binding this model is easy with a good quality transmitter. If you haven't bound a model aircraft before, then read a detailed instruction set on binding to the DX6i. The article talks about how to bind it to a RC helicopter, but the process is identical!
And now for the maiden flight...
The various planes found at Stevens AeroModel are gorgeous! I chose the Puddlebug for my son and I to build out, but I was very drawn to the Toon Scale RC Planes as well.
There might be a good opportunity to build out a second one.
So, the building of this laser cut model was very easy. A bit of CA glue and some patience is all that is needed. Shrinking the film over the wing was challenging until I switched to Parklite. Then it went on very easily the first time.
The electronics are great and will bind to any DSMX transmitter. If something breaks, it is very easy to find replacement parts as they are the typical UMX components found on most ultra-micro planes.
The final assembled plane is gorgeous! I almost want to keep it displayed on a prominent shelf so I can admire it. But, what good is building a plane and NOT flying it?
This will easily become a favorite after a few more flights. Knowing that we built it from the kit adds an special memory as well! I highly recommend this fun little RC plane kit!