How to Easily Modify the Super Cub for Maximum Fun
7 super fun hop ups for your Super Cub.
The Hobbyzone Super Cub RTF is one of the most highly recommended RC airplanes for beginners. It's a one box purchase and comes with everything you need to get you up and flying, including a sturdy foam fuselage and wing, basic three channel radio transmitter, seven cell 8.4V N-MH battery, gear reduced brushed motor, three channel receiver, and a two blade propeller. To reassure the novice, there's even anti crash technology built in. Flip a switch on the transmitter and the Super Cub will do it's best to keep itself upright and level, no matter what. It's easy to fly, cheap (and easy) to fix, and it looks like a scale model airplane, unlike some other beginner options. We've seen this plane crash full speed into buildings, the ground, and treetops and it's never cost us more than $10 to repair and half an hour to replace parts.
We still like to keep a stock Super Cub around to introduce new people to the hobby and just putter around - but after a few months of calm level flight it does feel a bit limited. When we got bored with our first one, we began to modify it. After we added a few new parts and pieces we found out our modified Franken Cub is a SUPER transitional plane for fast aerobatic flight, even without ailerons!
Hobbyists who have swapped parts on RC planes before
Basic - familiarity with drills, screwdrivers, and epoxy glues
What You Need:
- Hobbyzone Super Cub RTF RC Airplane
Upgrade and Mod Parts
- Spektrum DSM or DSM2 6-channel radio transmitter (or your preferred 6-channel radio)
- 14" long 3/16" carbon fiber rod
- T-28 Trojan elevator
- T-28 Trojan speed control
- Corsair 9 x 7.5 3 blade propeller
- Spektrum AR6200 6-channel receiver (or your preferred 6-channel receiver to match your radio)
- 2 Parkzone pkz1061 servos
- 3 cell 2100Mah Li-po battery
- 2 3/4" OD* wheels
- Custom plug n' play brushless motor mount
Here's how we did it:
Super Cub Spine
Before changing the elevator and rudder, we should have stiffened the frame of the Super Cub to withstand the greater forces generated during extreme Super Cubbing. In our experiments we reinforced after we upgraded and it cost us some repair time. Therefore, we recommend that you start by installing a "spine" made from a carbon fiber rod.
- Step 1 : buy (or cut to fit) a 14" x 3/16" carbon fiber rod, available at your local hobby store, and sharpen one end to a point - it doesn't have to be too sharp, just enough to "drill" through the fuselage foam
- Step 2 : measure it lengthwise against the Super Cub fuselage; line one end up with the tail then put a reference mark on the rod to ensure the sharp end is installed to the correct depth
- Step 3 : use the sharp end to carefully "drill" the rod through the foam in a straight line that will end up with the point sitting right at the tail
- Step 4 : pull the rod back out gently and straight, along the same line you put it in so you don't enlarge the cavity too much, then cover the point end with epoxy glue and reinsert it the same way
After the glue dries hard, you have a more rigid yet still very light fuselage that will withstand the higher speed flight force (and occasional crash) much better.
Now it's time to change the elevator out for one from a Parkzone T-28 Trojan RTF. The new Trojan elevator is made out of the same material and is very easy to install. It gives you more surface area for greater response from less controller input.
- Step 1 : remove the screws on the bottom of the fuselage that hold the rudder in place, then remove the stock rudder and elevator
- Step 2 : put the stock elevator on top of the new T-28 elevator making sure to align the leading edge of both elevators, then center the stock elevator side to side on the Trojan elevator
- Step 3 : mark the position of the holes on the stock elevator through onto the Trojan elevator; the center point of the holes is more important than OD**
- Step 4 : drill (2) two 1/4" holes and install the rudder assembly into the horizontal stabs
- Step 5 : reinstall the screws into the holes on the bottom of the fuselage
- Step 6 : reattach control linkage, paying close attention to make sure the movable elevator portion is flat with the non moving portion; if it's not flat, remove linkage and adjust as necessary
- Step 7 : do your standard pre-flight control surface check, then take a test flight: if your trim settings won't compensate for any climb or dive that's present, land and adjust control linkage as needed
Trojan Motor and Speed Control
Then we put in the Parkzone 480 brushless motor for more power and a 25 amp speed control to match. Woo hoo! Now we can take off in two feet or less depending on wind, as opposed to 10' with the stock setup. We used two shim washers between the firewall and the motor mount to compensate for the motor torque.
- Step 1 : remove several stock parts: propeller, cowling, gear box, motor, and receiver
- Step 2 : test fit the Trojan motor mount on the Super Cub firewall; you'll notice that two of the four holes will line up, and two new holes will have to be made; mark their positions
- Test fit the motor on the mount and mark each hole.
- Step 3 : using our photo as a guide, drill new holes into the firewall to align with the Trojan mount; we used a hot paper clip to burn/drill the holes in
- A = existing holes in black
- B = holes to drill in yellow
- C = holes that need washers in red
- Step 4 : install the Trojan motor mount onto the Trojan 480 motor using 4 screws
- Step 5 : gather four screws and six locking washers (we used the ones from the Trojan motor), then thread one washer onto each screw and screw the two right side screws in about halfway
- Step 6 : screw the left side screws in, adding an extra washer to each left side screw between the firewall and the fuselage, then tighten all screws down carefully, making sure you don't strip them
- A = motor mount washers in red
- Step 7 : determine your preferred location for the speed control, mount it, and route the wires (your mount location and wire run depends on your speed control and your preference - ours is in the cavity that used to hold the smaller battery)
- Step 8 : alter the stock Super Cub cowling to fit over the new motor; first test fit to see how much you need to cut out, then enlarge the opening using scissors or a sharp craft knife; when it fits, secure it with the three screws
- Step 9 : attach the propeller and make sure the motor rotates in the right direction** (if not, switch any two of the three wires to change the direction of rotation) and check for loose parts
With the new motor the Cub seemed to need more juice to really give us it's all, and we wanted more flight time per charge (who doesn't?) so we looked at battery options. We discovered that the Trojan 2100 3 cell 2100mah battery fits perfectly where the stock Super Cub receiver went. All we had to do was reverse the Velcro that used to hold the battery on the bottom so that instead it held the larger battery in place where the stock receiver used to be. It fits well and it doesn't affect the plane's center of gravity at all.
Three Blade Propeller
At this point we were still running the stock 9.5 x 7.5 two blade propeller, but the Cub just seemed to be missing something. We added the Corsair 9 x 7.5 three blade propeller and we noticed more pull and better flight response right away.
- Step 1 : remove the stock propeller by inserting a screw driver shaft through the hole in the prop hub and loosening the hub while holding the propeller
- For step one, insert a screwdriver in propeller hole parallel to propeller blades as shown.
- Step 2 : install the three blade propeller with the pitch numbers facing the plane (NOTE: this is backwards from EVERY other propeller we've ever seen - the rest have pitch numbers facing forward)
- Step 3 : replace the hub and tighten to secure the propeller, being careful not to over or under tighten; it should be a little past snug - sorry for being vague, it's a feel that comes with experience
WARNING: "Always keep hands and all objects away from the propeller, in case the motor is engaged! A moving propeller can cause severe injury and damage!"
- quoted straight from the Trojan manual
The next addition was a set of larger 2 3/4" OD tires to recreate the look of an Alaskan bush plane. The big wheels look cool, and help us roll easier over grass and rugged runways. You can find them at any hobby store that sells airplanes. The stock Super Cub rims are about half an inch wide, so pick a set with rims about the same width (but no wider than 5/8") that you like the look of.
- Step 1 : grab the lug with pliers and hold it while you unthread the wheels to remove them
- Step 2 : swap the wheels then tighten the lug down on the new ones until they don't turn, then slightly back the lug off until they spin freely
We have plans to add more goodies to our Franken Cub in the future, so we put in a Spektrum AR6200 6 channel receiver so we can use the extra channels to control lights, dropping devices, and whatever else we dream up.
- Step 1 : in the bottom of the Super Cub there's a foam panel with three holes in it; stick your finger in one and pull gently; it should come out easily (if not, risk pulling harder or consider a different location for the receiver - we'll proceed assuming you got the panel out without problems)
- Step 2 : stick the receiver box inside the cavity with double sided adhesive strips or your choice of adhesive; choose a centered location for a neutral effect on the plane's center of gravity
Our modified Super Cub has given us so many hours of excitement and fun we'll probably be flying it for years to come. We've flown and landed this setup successfully in 25 + mile an hour winds, and it also spins mean doughnuts; check out the video. If you have a Super Cub, and perhaps some extra parts from other planes, try some mods yourself. We'd love to hear from other hobbyists about what they tried and what works.
*OD = outside diameter
**The "right" direction is one that pulls the plane behind it, not pushes it backwards.
I do not get paid to write these articles. If you found this article informative please help support my efforts by clicking the Donate button.