shawnkilpatrick

Hi all,
I have purchased the Parkzone J3 Cub (brushless). I want to see if any one else out there has this aircraft. I would like to start pooling some information reguarding this plane. Mods, tips, problems... solved problems, stories and anything else is welcome!
I have attempted to put a 1000mah 11.1v lipo in place of the stock 7.4v lipo and have seen a substantial increase in power however some odd noises.... I think I may be pushing the ESC past its limits.
Any one hooked up to a watt meter to see what different prop options there are??

Hope theres a few of us out there!

shawnkilpatrick

No ones got a J3 Cub BL wow I thought someone might!

Grasshopper

Hi Shawn. I don't have the BL but do have the brushed. If the BL doesn't have a tail wheel,that's one of the first things I would add.

Please post how your flights go with it. I've been tempted to put a brushless system in mine.

shawnkilpatrick

I am currently looking into the tail wheel, and have added larger wheels (2 1/2") for the main landing gear.
Do you have any pics or tips on tail wheel selection and installation?

C140

I picked up a J-3 BL a few weeks ago. My thread on adding a tailwheel using a HobbyZone Super Cub tailwheel is down the Parkflyers page a little. I'm not sure how to phrase it into a post, so you'll just have to look for it.

Actually, I'll move it to the top.

shawnkilpatrick

So it looks like theres only 2 of un in the whole world that have the honour to fly the PZ J3 Cub BL! haha
Can any one tell me the rules on hiding the antenna? I steped on it while picking up my J3 one day and pulled the top cover off of the reciever!! Everything is ok tho and back together. In light of this I used a small piece of tape to hold the antenna to the left side (inside the fuse) back to the tail, then i taped it along the right side (outside the fuse) coming back up towards the prop. I heard that you werent supposed to overlap the antenna... will this work ok?

unloco2

Hi Shawn, the glitches are not because of the LiPos, Parkzone radios, for some reason have always been weirdly unstable. Don't know why, thats just the way it is. I have the old J3 Cub, the old Decathlon, (rebuilt several times) and the new Super Cub. Every unit exhibited glitches and in some cases, motor cut out. I replaced all the radios, and have not had problem one. I also replaced the motor on the J3 with a small Brushless, and the performance is outstanding. The main problem with the brushless one is simply excessive power, but that's why God invented throttle control.

Luck with your bird.

shawnkilpatrick

What parts on the system did you replace?

unloco2

I replaced the entire electronic package. Receiver, and the 5 lead servos, I had to add the brushless ESC and of course the motor. I found a replacement motor mount for the PZ J3 at my LHS, and used them on the J3 and the Decathlon. I believe the BL J3 now comes with 3 lead servos, so maybe the radio system will be more stable. I have also toyed with the thrust angle on the motor mount, since the small motors I'm using still have a tremendous amount of power. For battery power, I'm using an 850 MA 3 cell lipo from Common Sense RC, It fits in the same cavity as the NiMh battery that came with the plane, but I did have to cut 2 places on the top of the cavity to accomodate the difference in height. Yes, theres more, I also cut some cooling holes, where the cowl has an opening at the bottom just where the cowl comes close to the main body. The CG needs a little adjustment due to the lighter weight of the BL motor. I have the J3 trimmed, the Decathlon continues to have problems, only because it needs to be constantly flown. BTW, the motors and the ESC came from Heads Up RC on a combo sale. I suspect that the motor from PZ is stronger than the original Brushed power system, and should give you a lot of fun air time.

Other than that, they are both fun air frames.

megamoguls

I just bought a second hand Brushless cub. I had the Flyzone Cessna 182, it was so gutless it wouldn't fly.
The receiver is dead on my cub and I want to put my Futaba radio gear in.
None of the servos that came installed in the plane nor the speed control are keyed plugs, could someone reply with an orientation so I don't reverse something and kill it.
Not airborne with this one yet. I have been flying my Hobbico Super Cub, what a great plane that is. I am already looking less and less at my 1/2 airplane collection.

M

C140

If they're in the wrong way, they won't work, so try it both ways.

gzsfrk

On most Futaba-style receivers I've seen, the dark wire of the servo always goes to the outside edge.

megamoguls

I had a variety of problems using the remains of the original Parkzone radio. I was told that two servos were dead, but it was actually the receiver. Additionally although the throttle (Brushless ESC) worked with the Parkzone radio initially, it started acting funny and would not put out more than 30% power. I installed my Futaba radio gear with the Parkzone servos. After reversing the throttle servo direction all of the system works. The speed control lets the airplane nearly hover vertical. Yow, I can't wait for a calm day. I've dinged up my Super Cub too much on windy days.
The Yellow Cub is ready...

Thanks for the reply.

M

Paul Perry

Does anyone know the ideal distance from leading edge on this bird back to it's balance point?

C140

It flies well with the CG about 1/3 of the chord length back from the leading edge, or about an inch and a half back. The aircraft is not at all sensitive to CG changes, so you don't have to be exact.

doctor727

I also have the Parkzone J3 BL aircraft. Mine has the motor mounted with what seems to me to be excessive down thurst. It is not even flyable in this configuration. Has anyone else found this ? I am going to remount the motor to better align with the CL and decrease the down thrust somewhat. My CG is about the same as described earlier, 1/3rd of the wing chord. I an also increasing the control throws to afford better and chrisper flights. Any other help/suggestions will be great. The tailwheel idea is interesting. Will work on that as well.

C140

Doctor727-
The down thrust does seem excessive, but mine flies fine with it. The motor has quite a bit of torque, so it is necessary to have a down and right thrust line. The tail wheel is great improvement. As you may have already discovered, the plane doesn't have very good ground handling with the skid, and is prone to ground looping. The tail wheel takes care of the ground loop issue, plus it looks cool to taxi it around on the ground. The catch is that the tail wheel decreases the prop clearance, so you have to be more careful during takeoff and landing. If it becomes an issue, just make it a bush plane and put big tires on it. The only other thing you might want to do is put velcro on the wing struts. Any G-loading on the airplane will rip the little screws that hold the struts down right off.

Flyzit

Hello all. I'm new here to these forums and enjoy reading about all the experiences others have had flying. I got the J3 BL as a plug and play about 3 weeks ago to replace a cheap China knock off I had that was way too brittle. Had about 10 good flights and one bad one with the BL and wound up bending the motor shaft. Got a new shaft so now its time to send it back into the air.
Anyway, thanks for all the info you guys provide.

My planes: J3 BL, Super Cub, Easy Star, YB22, Slow Stick, Firebird Commander and a very modified Sky Fly.

Rob68

Is the PZ, J3 Cub, the cheapest lipo, BL, RTF?

gzsfrk

Nope--at least, not at the $160 price that seems to be the standard price for it. You can get the Exceed-RC 4-channel Pitts S-2A bipe RTF for $129.95 shipped, or the Exceed-RC Predator RQ-1L or T-34 Mentor RTFs for $124.95 shipped. Of course, Exceed-RC aren't known to be as high quality planes as ParkZone, but the Pitts bipe I got from them was top notch. The Predator, on the other hand--not so much. Wish I would have waited for the T-34 instead.

Rob68

I REALLY like that 4 channel Pitts S-2A bipe RTF!!! I have about mastered my Aerobird 3 & am wanting something with ailerons & more run time=lipo/brushless & don't have much to spend. Thanks a lot. That T-34 is cool too! In fact, I think I like it more now!

Lancifer

I just took my Cub out and i switched the wings over and forgot to fasten the friggen wing struts and man the wings folded in half during a nose dive and from 60 feet ...let me tell you it was disasterous !!!

gzsfrk

Ouch--really sorry to hear that, Lance. The one good thing about these kinds of mental mistakes, though, is that you're almost guaranteed to never repeat it.

Hope you managed to at least salvage some parts!

groundrushesup

You know it is funny how folks like me seem to stick to one thread at RCU or RCG or here at WF, not even thinking there might be a similar thread on each of the three I should keep track of.

Anyways, I have had the J-3 BL for about 6 months or so now, and it has become my daily flyer / Frankenplane. I replaced the wing after a 'strut' failed to do its job on a tip stall (yeah pilot error), and I've reinforced a lot of the innards with balsa and some BluCor. Third flight ever I stalled in a gust of wind and from ~3 feet high, and the bounce on the tail broke the stabilizer and the elevator almost clean off. took it back to the shop, laid a 1/3" balsa rod into the crevice along the inside of the bottom of the fuse and gorrilla'd the bloody snot out of it. Hasn't budged since.

Completely removed the rudder, replaced the lower hmmm say 1/4 of it with a rigid plastic, and put the rudder back on with 3 3/4" CA hinges. added a large tailwheel to go with my 2" Dubros up front, which makes for great ROG's.

One other mod - I removed the frame from the shell so I could reinforce the skimpy and almost made-to-break connections from the firewall plate to the battery cage. If you don't know what I mean - other than two plastic protrusions of about 1/8" each, there is no support for the connection between the firewall and the rest of the frame. I dremelled up some BluCor to fit and GG'd it in place. Now it can take a bump on the nose without internal injuries.

Just wanted to post a few pics of my J-3's latest incarnation. I was trying to think of a scheme that would excuse the beaten-to-hell look, and voila! It came to me.

Upgrades include an Atlas 400XT BL from Hobby Lobby (one of their $18 steals), a 25A Mystery ESC, and the TP Prolite 910Mah 3S LiPo. Stock servos with a Spektrum AR6100 / DX7. Had to put three quarters in the cowl and remove some downthrust because of the motor, and I am flying it with an 8x6 Master Airscrew (durable as all get-out)

Via Con Dios, Mis Amigos!

jecchile

HI! groundrushesup...
What kind of paint did you use on the foam?, Cowl?.
Thanks.