BJ-J3 Cub - Swappable Plans & Build Instructions

by banditjacksRC | February 23, 2015 | (28) Posted in Projects

I want to start off by saying- this Flite Test community is awesome. This was my first attempt at making my own set of plans to share with the community and was definitely having some issues. My first two beta builds ended in complete disaster (and an exhausting climb to the top of a 30' tall tree!).

I decided it was time to see what the community thought and posted my story on the forums... the help came pouring in. The thread is a perfect example of how the members are always willing to contribute whatever they can to help others. You can see the full fourm thread HERE!

A couple other members used their own resources to build this design and after collecting everone's input a general consensuses was determined that the airfoil on the wings were a bit too tall, the vertical stabillizer was a bit undersized and a few other small details were needing to be fixed.

Everything was squared away on the design and here we are. She now flies better than ever.. see for yourself!



BJ- J3 Piper Cub - Plans and Build Instructions:

 

 

PLANS:

BJ-J3 Cub PLANS

 

Build Instructions:

Wing Build:            Wing Build Instructions

Fuse Build:            Fuselage Build Instructions

Tail Build:              Rudder and Elevator Build/Assembly Instructions

Final Assembly:     Final Assembly

 

SPECS:

Wingspan:    40"

Lenght:         25 1/2"

AUW:            510 Grams (w/o battery & with landing gear)

Swappable:   YES

Build:             Easy / Beginer

 

Electronics Used in This Build:

Motor:      NTM PropDrive 28-26 1200kv 268W

ESC:       30A Turnigy Plush

Servos:   HXT900

Battery:   Turnigy 2200mAh - 3s 25c LiPo

Prop:      APC 8x6E or APC 8X4E

*Please note: The BJ-J3 Cub is FT Power Pod compatable and all the electronics I have incorporated for this build is perfect match for almost all of the larger FT designs. I have personally used this exact setup with the FT Storch, Bloody Wonder, Versa, Spitfire, Racer and the FT-22. It works great with all of them!

 

Maiden Video:

 

 Review:

In my personal opinion this model is amazing in many ways. To begin with, this Cub flies fantantastically. Easily capable of mild aerobatics such as loops, rolls and spins. It tracks like an arrow with a good deal of stability. It also has a great speed envelope. You can zip around the skies covering lots of ground quickly, or pull the throttle back and float her around. You should use rudder for coordinated turns, but this design does fly great as a bank n' yank as well.

This design would also make a great first plane, or for somebody in the early stages of learning to fly RC. The build is very straightforward and would be perfect as someone's first. When you take the aerobatic capabilities into account, it makes it a truly fun plane for all levels of experience!

Don't take only my word for it!!! You should build it and see for youself!

 

"It flew VERY VERY WELL."

-mrstamp80 ~ Posted on forum thread


"The plane flies alot like my umx carbon cub ss."

-jh1985 ~ Posted on forum thread


If you have any questions please feel free to ask. I am on the forums under the username: BanditJacksRC. 

THANKS FOR READING!!

COMMENTS

LordVader on March 1, 2015
That is awesome. I have a Hobbico Cub and it hasn't faired as well as yours. Great build, thanks for sharing. I'm gonna build this. Keep sharing.
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jrvalentin62 on March 1, 2015
As I said before. Outstanding FT community! Your design BanditJacks is awesome. I can't wait to get mine in the air. Parts in the snail mail (HobbyKing). ClearSkiesCalmWinds.
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banditjacksRC on March 1, 2015
Thanks guys! It sure is a fun one to fly.. can't wait to see 'em!
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DavidTWT on March 24, 2015
I am new to building but got it built tonight. It say FT Power pod compatible but do we need to redesign the power pods size? The power pod is so small sitting inside of it.
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banditjacksRC on March 28, 2015
No I use the normal sized PP. The fuse walls don't sit right up against it or anything, but if you have a bbq skewer through it you will be good. Good luck!
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MT Alex on March 2, 2015
Fantastic article, nice layout, and I love all the PDFs with the info. You certainly put in a lot of effort, thanks a bunch!
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RickN on March 2, 2015
I love it !! And I already have everything to build it, except landing gear. Even have the same power package. Just need to make a stop at Dollar Tree and I'm on that puppy ! And right here at FT for wheels.
Thank you, immensely !
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Krivak957 on March 2, 2015
Very high quality on the plans and build instructions. Anyone who has watched a FT build video (e.g., FT Spitfire) will be able to follow your instructions easily. Is the model painted? Or covered with packing tape? If painted, did you Minwax first, or just spray lightly?
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banditjacksRC on March 2, 2015
Thank you everyone!
The cub was spray painted with 2 VERY light coats. If you hold the spray can about 8-10" away, and use light coats, you don't have to worrie much abou the foam melting. The decals are printed on regular office paper and glued on with spray adhesive (3M super77)
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earthsciteach on March 2, 2015
Congrats, man! That is a little rocket you have there! I'm glad to see you persevered and nailed it down. I will put this one on my build list. I really like the looks of it!
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banditjacksRC on March 2, 2015
Thanks earthsciteach, for the kind words and for the help along the way.
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Yogenh on March 2, 2015
You did a great job and it flies fast.

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RcMatt on March 2, 2015
Awesome build. One thing I have found with thrust testing that ntm 28-26 1200kv motor is that it puts out about 200 more grams of thrust with a 8x4.5 gemfan than that of a 8x4 or 8x6 apc. Quite interesting results.
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banditjacksRC on March 2, 2015
No kidding! That's very interesting. I've always wanted to do some of my own testing but my scale maxes out at 500g. I am planning to build my own quad copter this month so I think its time to upgrade and test some motors/props out myself. Thanks for the tip!
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1959cutter on March 3, 2015
I want to blow this up!
as in 200% like the FT spitfire,and am trying to finish the 200% swapable corsair by "filkin",seems the motor and other parts are frozen to the ground in georgia at grayson LOL!
the winter has afected the mail delivery, i'm sure.
I want to see this with 80" wings.
glad to see more people from arizona on the site!
beautiful design!
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banditjacksRC on March 3, 2015
That would be pretty awesome to see an 80" version.. and you now have my wheels turning, lol! Where in Arizona are you? I have been a bit worried about when the weather warms up, and my hot glued planes falling apart in my 120deg garage.. have you had any experience with this at all?
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1959cutter on March 4, 2015
i live in Az city,and have a 50 acre flying field near my house

i am finding that giant planes are more forgiving and easier to build(just more foam and glue/tape)
plus compared with $1500 for an ARF balsa plane of the same size, it's a steal ,$200 for power system and servos from grayson. it can be made swapable,just 200% power pods made from wood.
if you are new to arizona,you will find that a small window (1500 BTU) AC will be needed,if it is too hot for you to be in there,its too hot for the glue would be my guess.
my workshop is a windowless insulated shed i keep airconditioned as i work out there also,and i use wax that has to be kept at under 80 degrees,is the excuse i give my wife for the extra juice used to live in comfort.
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ewlie on March 3, 2015
Hi Tom,

It looks like an excellent design, very nicely presented. I'm keen to have a go. Thanks!

Here in Oz our foam is a little heavier and I've had trouble getting the balance right on FT planes. I tend to need a bigger battery to get the CG in the right spot.

Where is your CG? I don't see it marked on your wing.
How far forward to you place the 2200mA battery in your particular build?

Thanks
John
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banditjacksRC on March 3, 2015
Thank you!
The CG is pretty much right under the spar. Although I like to balance it a bit nose heavy of that point to be on the careful side. With this design my 2200mAh lipo is placed almost all of the way forward of the PP. There is probably a few mm of extra room for the battery to be moved a bit further forward to accommodate for the heaver FB. I havn't done any exact measurements but the wing load seems great enough to where if you needed to add any extra nose weight you would be okay.
I hope you decided to build it. Its a great flying plane!
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ewlie on March 31, 2015
Thanks,

I was wondering why you choose to make the wing thickness less than FT designs (Racer, Dusty) where a 9g servo fits between the foam. You have one side of the foam carved out, why is that?

John
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msh312b on March 3, 2015
Awesome! I love the Cub, I have a 90" stick built one, but this will be great to just throw in the car and have whenever. I get building it right away....just after I build the A-10. ;) Keep up the Great work.
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banditjacksRC on March 3, 2015
haha.. I would love to build the A-10, but need to get the EDFs first! lol
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808aerosquadron on March 4, 2015
Well designed airplane and well written instructions. Thank you. I foresee this joining the hanger soon.
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hen10chus on March 4, 2015
First, thanks for the build. I didn't see how you would handle the in/out of the battery for charging. I suppose it is placed onto the PP. Do you take it out after taking off the wing? Or move the PP every time? Thanks.
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banditjacksRC on March 4, 2015
The Lipo is held on with velcro to the bottom of the PP. With the 2200Mah at the very front for balance, you don't even need to remove anything! It back edge slips up and in and fastens to the bottom of the PP. There are more detailed pics in some of the build tutorials so you can get an idea of how much room there actually is.

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hen10chus on March 5, 2015
Again, thank you so much for the design. I am going to build this one for sure. I have a very old version super cub, just looking to convert it to brushless motor, lipo battery, adding ailerons, and with that I will have to put in my own radio instead of the stock 3 channels. Now it is so much more economical and so much cleaner to simply build this BJ-J3 cub of your design. That's why I was so much into how to place the lipo battery.
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Nathan_116 on March 6, 2015
Wow, that thing zips aroundthe sky. I have a feeling if i build it a smaller prop will be in order.

Nice Build!!!!!!!!
Nathan
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shawndae on March 6, 2015
You plans and instructions are very well done. Mine is about 90% done and only needs the servos hooked up. I will give her a try this weekend. I can tell by the way the plane feels in my hand that this is going to be a good flyer. Thanks for taking the time to provide to all of us this Article, plans and build instructions. You are one of the guys who helps to make this site so good.
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banditjacksRC on March 6, 2015
Thank you! Good luck with the maiden. I'm sure you will love it!
And more designs are on their way!
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umairf on March 7, 2015
OMG man thank youu sooo muchhh .. i've been searching plans for this bj j3 cub since 7-8months..
and very very neat and awesome build :)

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banditjacksRC on March 9, 2015
I'm glad you like it. I was the same way, looking all over for a good set of J-3 plans, but couldn't find anything that was as scale looking as I wanted. There are a few cubs out there, but the stabilizers and wings all looked a bit off. anyways I hope you decide to build her!
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umairf on March 13, 2015
yeah sure I'll Build one :)
just waiting for my exams to finish :l
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thrasher0815 on March 8, 2015
Hi Banditjacks,
Thanks for the plans and instructions. She sure looks beautiful and seems to fly great.
What do you estimate the stall speed is? I would like to underpower it a bit to use it as a trainer plane and yours sure goes too fast for a begginer like me ;)
If it's not "the beef", what other engine would you use?

Cheers and keep up the good work!
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banditjacksRC on March 10, 2015
I am not too sure what the stall speed is, but it handles stalls amazingly.
On the build thread MrStamp80 did this build and used a much smaller turnigy brushless motor and it worked great.
I am sure it would fly well with the well known "blue wonder" as well, (i have been wanting to try that out actually) and the lighter weight setup would help a lot with a much slower stall speed.
Thanks!
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Robb on March 9, 2015
Hi BanditjacksRC, a big salute from Panamá, in Central America.
Thanks for the plans and the step by step for this great project. I would like to ask you which push rods, linkage stoppers and control horns you used for this project. I have noticed you used parts from HK, so I am planning to buy the whole electronic package and the parts above.
Thanks in advance for your time,
RoBB
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banditjacksRC on March 10, 2015
Hey Robb!
The push/pull rods are 1mm piano wire. The linkage stoppers I purchased at my local hobby store, but are the same the the flitetest store sells. I believe HK sells them as well (1mm linkage stoppers). And the controll horns I did purchase from the FT store.
Good luck and have fun!
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Lupus on March 10, 2015
Nice. Love the way it looks to fly.
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raydar on March 17, 2015
A quick question, if I may. Does the thrust center line require any offset(s)?
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banditjacksRC on March 28, 2015
I usually don't put any on, but a little down and to the right wouldn't hurt. especially if you are using the 2826 like in the video or anything bigger you might want to try it out.
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91shadowrider on March 24, 2015
Built and flew mine today. It has a nice glide but it will tipstall. Mine did and crashed . Amazingly it didn't get hurt. Make sure you have enough downthrust on your build. I shortened my powerpod so I could install my elevator and rudder servo inside on the floor of the fuselage under the wing. By doing so I was able to get it to ballance with a 500mah 3 cell. I hate tail heavy planes. I also doubled up the foam in the nose for extra strength and I am glad I did. I think that is why it did not get damaged on the crash. I fly mine with a 1000 mah 3 cell or a 500 mah 3 cell. My only other complaint is I think it would fly better with a little longer fusealage. just my opinion ... Thanks for the free plans and keep building.
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banditjacksRC on March 28, 2015
awesome! Im glad you liked it. Somebody in the forum thread did the same with the elev/rudd servos and i though it looked great. And im sure it helped keep some weight more forward. A longer fuse would absolutley help, but was going for scale and simple.
Your right about this thing holding up. One of my J-3 build i have wrecked MANY times.. and one was reaallyy bad, and it just keeps on chuggin'. haha
Thanks for the interest!s
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giovanni08 on April 2, 2015
is there anyway where i can print the wing plans, type them together and cut them out? i tried printing the plans but it only allows me to print them full scale which they all print on 1 piece of paper rather then several sheets to tape together... help please
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1959cutter on April 26, 2015
if you right click the mouse after opening the plans, it will bring up the little grey window click "print" and on the window it opens, click "poster" and to your right it will will show a dotted outline section of the plans with a number of pages it will take and size in inches it will be.
hit the "print" button button and it will print 18 pages "tiled" and ready to tape together!
and if you want to build build a GIANT plane just change the size to 200% and get ready to do a lot of taping and trimming!
I hope this helps.
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darneto on May 14, 2015
I am trying out these plans :)
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Garreta234 on June 9, 2015
The plans are very nicely done. I found that John Deere yellow is a very close match to the original j3 paint job. I found that using electrical tape works great on the side decals.

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umairf on June 27, 2015
hey everyone
can i use 1200kv Bell motor with 18Amp Esc for this build ?
Help
Thanks

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bthom84 on July 6, 2015
Best plane in my hanger! It flew without hardly any trim right out of my hand on the maiden. I'm using a 2212-13 1000kv motor with a 9x3.8sf prop. Beautiful plane, I couldn be happier!
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richymon1 on September 4, 2015
Beginner here to the FT community and I really like cubs having flown the big one with my Dad so for my first build I am using your cub design I noticed a discrepancy regarding Fuse length between your write up "plans" and the stats in for the length your video.
Build plans call for 25.5" length and the video states 35" length which should I use for fuse length? I plan to use rudder and elevator control only as it is recommended for first time flyers is this what is called bank and yank control?
Your plane looks fast in the video is there also some way I can make it a slower flyer to start with until I get the hang of it all maybe motor or prop. recommendations?
Any advice or pointers you can provide would be greatly appreciated, and great job on the buld it looks really good, many thanks
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Hữu Nghĩa on June 28, 2016
Thank Tom,
It's a nice looking and good flying plane. I'll try it for my first flight.
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Hooter on August 22, 2016
I made a big mistake or 10. First build of a foam board plane and may have got a bit heavy handed with the glue gun. A few of my balsa scratch built tricks don't transfer to foam. C of G slightly aft.
1st Maiden flight...ground loop. 2nd flight, took off and things looked good turned down wind and throttled back. Turned to come into wind and she stalled and nose dived into the ground. Mental note....thrust is a must, and height above ground is essential when sorting the plane for the first time. Fortunately rebuilding foam is a lot easier than the old traditional build.
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Jaredbradt on December 14, 2016
200% of this would be sweet
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Vishal Bharat on March 3, 2020
Indeed a Superb Post, for which i was looking for.

As im at beginner stage, kindly Help me to provide with the Motor mounting, ESC Installation and Battery placement. The Cutting and Assembling job is done.

Thanks in Advance

Sincere Regards


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Vishal Bharat on March 3, 2020
S.O.S

Anyone?

With a Piece of HELP??
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BJ-J3 Cub - Swappable Plans & Build Instructions