How to Make Piper Cub J3 RC Plane (DIY Foam Board)

hello guys it’s me again Julius thank you for visiting this channel in this episode i’m going to share with you how i make this beautiful piper cup rc model rc plane model this is j3 version you can see on the engine cowl and the dummy engine all the details here are on the plans you can make it like this by following the plans and if you can see here there is a pilot there, pilot figure this is the same pilot as the sky arrow but i made 80% smaller the wingspan of this plane is 130 centimeters or about 51 inches with the flying weight at 850 grams with a 3s lipo battery 2200 milliamps hour this plane haven’t fly yet i hope it can fly and landing safely i will maiden it tomorrow and okay let’s build this plane check it out the plans is free you can find a direct link to the model page on my website on this video description cut each segments with cutter knife and then combine them into a single part according to the parts number and then trace the part on foam board i use five millimeters depron or polyfoam finally cut the foam with cutter knife you can see here the left and the right wall are not the same the left one is a bit longer than the right it’s purposely designed that way to angle the motor a bit to the right to compensate the motor torque because if the motor is straight the plane will keep turning to the left you need to sand a bit at the bottom of this part because it will be attached a bit angled inside there are two formers from three millimeters plywood because we will use clear cabin window thus it needs more strength to support the wing this one is a special former by using 2.5 millimeters wire and three millimeters plywood i use bicycle wheel spoke wire

there is a substitute to this part by using all plywood former so you can choose which former that you want to install use sewing thread and ca glue to attach the wire to the plywood i use the wire former because i want to add a camera inside the cabin if i use all plywood former it will ruin the scale do not flip this part use heat gun and metal pipe to curve this part okay this fuselage is already sanded smooth on the all edges with wet sanding i use medium 240 sandpaper to do the job and finish it with 1000 smooth sandpaper by using a guide from the plans cut the engine cowl like this this is how i make a firewall from three millimeters plywood i used 2830 1000 kv brushless motor

before we go to the next step we need to cover the fuselage with packing tape start working on the bottom side and then cover the top sides and eventually both sides this is how i cover the cowl cut packing tapes in small cuts and use covering iron to smooth the cover i want to share with you how to detach the cowl to remove or replace the motor first we need to attach it to the fuselage use small amount of glue like this and then by using a hot knife slice off the glue gently to detach the cowl you will have a clean and neat result with this technique

and then attach the cowl again prepare the tail for vertical stabilizer like this sand the leading edge into rounded shape cover it with packing tape before attaching to the tail make sure the fin is straight to the fuselage prepare the rudder by sanding the round edges into rounded shape and sand the edge on the hinge like this add hinges to the rudder with plastic from any packaging like this try to attach the rudder but do not glue it yet install two servos for elevator and rudder i use nine gram cheap plastic gear servo test both servo and place both servo arms facing inward like this right servo for the elevator and left servo for the rudder i use push rod wire from waste outdoor fiber optic cable make holes for each push rods according to the plans install push rod to the servo arm make push rod guides from roll of paper like this and install pushrod with pushrod guides like this do the same for the other servo add eva foam to secure push rod guides on servo platform like this here i use the same paper pilot figurine as sky arrow but i made it in 80% size you can watch how i made this pilot figurine on sky arrow episode it’s made out of paper i used eva foam cut into small pieces to help mounting the cabin glass and use 0.3 millimeters mica plastic for the cabin glass cut according to the plans like this attach the roof of the cabin or a plywood part that will receive the wing with ca glue or epoxy glue make sure the roof is the same height as the top of the cabin glass if you short on this just prop the roof to be the same height i use UHU glue to attach my plastic to the fuselage

use vinyl stickers to make the frame of the cabin windows like this sand the surface that need to be paint with medium grit 240 sand paper in this case is the front section of this aircraft i use red rj london spray paint and use combination of paint and stickers to make the color scheme here are white final stickers that i paint red to match the paint color on the nose you can see here i bend three millimeters bicycle wheel spoke wire to make landing gear strut i use three millimeters plywood as a base use ca glue as temporary glue wrap around the wire with paper masking tape before glue it to the base and i used 2.5 millimeters wires and support struts like this i use small cable zip ties to tie the wire to the base also add dummy suspension struts like this as a detail accessory use mica plastic to cover the landing gear strut paint it red like the fuselage

peel off the cover before gluing the landing gear make this tail wheel setup by following diagram on the plans i use the same wire as the pus rod add stoppers with sewing thread and ca glue make a roll of paper to mount the tail wheel before we put the tail wheel and rudder to the tail we need to install the horizontal stabilizer first sand the leading edge into rounded shape also sand the elevator edges and then cover all of them with packing tape install the elevator to the horizontal stabilizer with plastic hinges and then add a wire connector to connect both elevator like this i use 2.5 millimeters wire prepare the tail for the elevator by using a guide from the plans once the horizontal step is already installed glue the tail wheel wire with roll of paper to the tail like this and finally install the rudder with the wheel wire inserted inside like this apply stickers that are supplied by the plans on the nose like this cut it right on top of the cowl seam for easier maintenance i use 10 millimeters eva foam for the engine block and mica plastic for the air intake like after they are assembled paint them with black

and i use three millimeters eva foam to make other details like this and use any cable that i can find that match the plans and paint them silver assembly all the parts like this add three millimeters eva foam in between dummy engine and the nose to for easier maintenance this is how i make the battery hatch door cover it with vinyl stickers and paint it red make a simple lock like this with a servo arm there’s no need for battery tray just insert your battery esc and rx there it will be balanced on cg this is optional detail inside the cockpit for the bottom part of the wing we only need a bit curve on the front portion like this sand the leading edge and then attach the formers and spars this is a spar also function as a wing connector it’s made out of three millimeters plywood this is already hardened with ca glue and covered with packing tape to add strength install the plywood spars like this this is also optional for you who want to make an opening on top of the middle wing add this black sticker to add depth for visual detail also add these wires as details sand the trailing edge before closing the middle wing put the middle wing on top of the fuselage to make sure it is on the center use the plans to mark the screw position here i made a mistake don’t trace the front window yet before screwing the middle wing down and then trace the front window also glue the bottom of the leading edge to the fuselage cut the front section of the middle wing like this remember to glue the front section to the fuselage first unscrew and detach the middle wing the

front section will stay on the fuselage cut the leading edge for making window and cover it with packing tape use eva foam to help glue the mica plastic cut all holes on the bottom side of the wing mark the spar position by using the middle wing sand the leading and trailing edge and then assembly the wing mark the spar position prepare the top wing part by curving it i use foam glue to glue the foam spars and then close the wing with the top part this is how i close the wing sand all edges into a rounded shape including leading and trailing edge and then cut the aileron using a guide from plans and then prepare the aileron like this cut the window on top of the middle wing this is optional you can replace it with provided sticker make holes for several cables like this install servo for aileron i use cheap 9 gram plastic surface like this you need to extend the cable longer insert the servo cables first before combining three segments of the wing together add one centimeter prop on each wing just below the wingtip seams to make the wing a bit dihedral fill any gaps with hot glue and then combine two servo cables into one input and then cover the wing with packing tape add mica plastic to the wing window add a piece of foam to prop the gap on the aileron

so it will help to grip the horn later also add my plastic to protect the foam around the screw holes like this these are plywood parts that will be installed to the wing and later to be connected to the wing struts cover all of them with white vinyl stickers to match the wing color install them to the bottom of the wing like this here i used two millimeters balsa sheet to make wing struts follow these steps to make wing struts wrap it with masking tape to add strength you need to add a piece of wire and nylon thread on each tip of the struts the wire is functioned to secure the strut and nylon thread to latch onto the screws to make it more secure finally paint them white this detail is also optional i use elastic thread to simulate bracing cables on the stabilizers add control horn on elevator and rudder

also add control horns on ailerons connect control horn to the push rods and add stoppers do the same on ailerons mark the cg points with screws the cg is about 6 centimeters or 5.8 centimeters from leading edge finally close servo holes with card or plastic i already tried several attempts to landing this cub properly

but i still couldn’t do it this one is the most correct approach compared to other attempts but not enough space so i crash it to the ground before inflict more damage so i installed bigger wheels in attempt to make it easier to land this cup these big wheels are handmade by my friend Wewet Drajat thank you bro it looks awesome just like a bush plane it reminds me when i made my Wilga so many kite threads on this field it’s time for review the first is about the design of this model plane

the design is very similar than the cessna 172 with the two formers that supporting the wing and also with the clear cabin windows like this if you can build cessna 172 you also can build this piper cub but the piper cub has more details as you can see here landing gear has more additional landing gear struts also bracing cables like this and the dummy engine also detailed cessna doesn’t have that and the transition from the windshield to the wing on the cessna 172 there is only sticker on the wing but on this piper cub i made a like a real one like this so the piper cub definitely has more details so the because of that the build time also longer but the difficulty level how to build it is about the same as the cessna 172 if you don’t want to make these windows or this windows i already don’t worry i already made a set of stickers windows stickers that you can use it alright guys now it’s time about flying performance the flying performance is also about the same as cessna 172 but this plane feels a bit lighter because the bigger ring area but to land this plane it needs special technique it’s a bit tricky i finally managed to land it landing it safely with longer runway than usual okay this project is finished you can build this model using my plans the next project will be i will continue our next project dc-3 part 3 okay thanks for watching if you like this video consider to subscribe and click the bell icon so you can be notified if i make a new model like this okay thanks again see you in the next episode