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View Full Version : J3 E-flite Cub completed


donjiskra
02-04-2007, 07:08 PM
Just finished assembling the J3. It's a great model from E-flite.
I installed an AXI 2820/10, Berg 7P receiver, HowHigh Altimeter, Master Airscrew Electric 11x6 wood prop. Seperate aileron servos which provide full flap control also. The AXi provided 359 watts (.48 horepower) and 74 watts per pound,
Originally installed in the Bonnie20 with floats, so I knew it could easlily power the Cub.
Can't wait for some nice spring weather.
Here's the Electricalc data.
Next project a Kyosho Soarus1600 v-tailed sailplane, powered by an SK400XT.
Happy flying.
Don

max2112
02-28-2007, 07:21 PM
Looks good Don.

Is that a little you sitting in as the profile pilot?:D

donjiskra
02-28-2007, 07:59 PM
Sure is, get's a big laugh.
Don

alienx
03-02-2007, 09:55 PM
Good job!

I've wanted a bigger cub for a while. I thought it would be this one but now I am interested in the H9 version. Can't make up my mind.:)

SilberIgel
03-02-2007, 11:44 PM
Yergonnalovit!!!!

Took mine out today. It is sweet!!!

Just remember it is a 'Cub' and it flys like a 'Cub'....

Aussie E-Flite
03-03-2007, 09:25 AM
My E-flite Cub arrived this week and just started assembly today - looks great, judging by the forum comments, should be great to fly as well.

alienx
03-03-2007, 11:26 AM
Yergonnalovit!!!!

Took mine out today. It is sweet!!!

Just remember it is a 'Cub' and it flys like a 'Cub'....
What does a Cub fly like? Do you mean just big and slow? Not warbird?

I've read about people having trouble flying them, but I haven't seen any of that in my short experience with mine. I started the hobby on a PZ Cub and I also have that 47" Chinese one that came through here a while back. They fly similarly to me, but no problem. Very stable. If anything, just a little underpowered, in relative terms anyway.

SilberIgel
03-03-2007, 02:42 PM
First, mine has plenty of power with the E-Flight 25... it flys well with maybe 55-60% power. However, its a slowish, gentle flyer due to its big, thick, wing. Looks very scale-like in flight. Gusty winds will push it around and headwinds slow it to a crawl.... like the full scale. I've flown mine in 7 G 10+ winds and you do have to stay on top of it.

It flys like a 'Cub'.... meaning that its a 'throttle & rudder' airplane. Power management is important but you must get really handy using the rudder. You need to use the rudder ALL the time just like on the full scale. Coordinated turns are a 'must learn' technique. Also, like the full scale it doesn't like steep banking turns ... it will slow down and the nose will fall down into the turn. Get too slow and it will stall.... just like the full scale... and probably enter a spin. So you should probably know how to recover from a spin with minimal altitude loss. It lands and takes off like a "Cub".... meaning you need to manage the power AND the rudder on take off to avoid a ground loop. And you fly it to the ground keeping a bit of power on for a good landing and be on the rudder to avoid a ground loop.

You might like to work on 'forward slips'... (I'm perfecting mine!!) for landing approaches and crosswind landings as it do want to float along with that big wing.

I think it takes a bit of experience, confidence and skill to fly the Cubbie and I'd not give it to a beginner. Nevertheless, once you have learned the basics, its a plane that can, and will, make you a much better pilot (witness all the WW2 pilots that the Cub taught to fly!).

That being said, its a real blast to fly... 'just like its full scale Buddy'. Nothing better than to take off and fly around the pattern in big lazy circles and figure eights. Grease a landing and 'back taxi' to the pilot's station. Put the 'stick in your groin and work the 'rudder' and throttle' and she'll trundle back to you with the prop reving and then ticking over; she'll bob and bounce ... landing gear working and flexing over the rough ground looking right smart. When you get back to station, full rudder and a blast of power and she'll swing around. Let her idle for a couple seconds, then chop the power ... the prop stops giving that little "Contental" kick back. Listen close and you can hear the "tinkle-crackle- tink'- tink'-tink" of the exhaust headers and muffler cooling down. You might just catch a wiff of av-gas and that dope and fabric 'old airplane' smell.... Its a rush!!! It will put a very big smile on your face!!!! :):):):)

Yep! It IS a Cub....

(Oh, did I mention that your flying buds are in the back ground chanting.... "I want one! I want one!"?);)



What does a Cub fly like? Do you mean just big and slow? Not warbird?

I've read about people having trouble flying them, but I haven't seen any of that in my short experience with mine. I started the hobby on a PZ Cub and I also have that 47" Chinese one that came through here a while back. They fly similarly to me, but no problem. Very stable. If anything, just a little underpowered, in relative terms anyway.

alienx
03-03-2007, 05:27 PM
Sounds cool. I think I get it. My 47" flies like that too. I guess it's the ariframe. Definitely a plane that seems to require some "discipline" more than a higher powered warbird does.

I tired a touch and go recently with mine because I finally got a paved surface to use. I couldn't get it lined up so it ended up be a go-around, but it was beautiful nonetheless! I was trying to side-slip my way over the fence next to the road and got low, so I hopped the fence and just powered back up and it tractor pulled its way out of the failed attempt at a touch and go.

Lots of fun to fly for sure. I guess that's why I want a bigger one now.

Solid Hit
03-21-2007, 09:57 PM
Oddly enough my Cub 25 will actually fly like somewhat like a sport plane. She'll roll, loop, and fly inverted. I'm using all the recommended power equipment right down to the prop and she is a big 'ol blast to fly!

harrymc
04-02-2007, 05:37 AM
Hey guys,
For those of you who been thinking about float flying with this aircraft, here's a video we took this past weekend. We're using a temporary field out in the country while our new club field is being built. The temporary field has a big pond a few hundred yards away. The pond is not an ideal place to float fly being that there are a number of trees in the water, both upright and laying down as well as stumps and brush as you can see in the video. But I figured with a small group of guys standing there they could serve as my extra eyes for lookout. While taking off I had to adjust my path to avoid flying too close over the heads of the guys and when coming in, a small adjustment just before touch down to avoid an overflow pipe just to my left. Rather like skipping through a minefield coming and going but it turned out alright. Float flying is always fun and with this aircraft it really is a breeze! http://static.rcgroups.com/forums/images/smilies/biggrin.gif

Click here to view the video (http://www.harrymcwilliams.com/Cub_on_floats.wmv)

Harry
http://static.rcgroups.com/forums/images/statusicon/user_online.gif http://static.rcgroups.com/forums/images/buttons/privatemsg.gif (http://www.rcgroups.com/forums/private.php?do=newpm&userid=47051) http://static.rcgroups.com/forums/images/buttons/find.gif (http://www.rcgroups.com/forums/search.php?do=finduser&userid=47051)

donjiskra
04-05-2007, 12:54 PM
Excellent video, much appreiate your posting!
Sure looks like a great fkyer.
Don

Solid Hit
04-05-2007, 10:03 PM
Great video Harry. What size batteries are you using?

rea59
04-05-2007, 11:01 PM
Great video Harry!!! :D

I've debated using floats on my cub just to avoid ground loops.

harrymc
04-05-2007, 11:51 PM
Thanks Guys!

E-flite calls for a TP 4200mAh 11.1v pack.
I'm using two TP 2100mAh 11.1v packs wired in parallel since I have about 10 of these packs and no 4200mAh packs.
PLENTY OF POWER!
If you've never flown off water, you gotta try it. It's a ball!

Harry

Solid Hit
04-06-2007, 12:39 AM
Exactly what I am using .... and I have a large pond on the side of my farm. I've flown a Slow Stick flying boat from here but have been debating about the Cub. hmmmmmmm. :rolleyes:

Hal-i-chopter
05-07-2007, 04:43 PM
Float flying is always fun and with this aircraft it really is a breeze! http://static.rcgroups.com/forums/images/smilies/biggrin.gif

Click here to view the video (http://www.harrymcwilliams.com/Cub_on_floats.wmv)

Harry
http://static.rcgroups.com/forums/images/statusicon/user_online.gif http://static.rcgroups.com/forums/images/buttons/privatemsg.gif (http://www.rcgroups.com/forums/private.php?do=newpm&userid=47051) http://static.rcgroups.com/forums/images/buttons/find.gif (http://www.rcgroups.com/forums/search.php?do=finduser&userid=47051)Harry, The link is no longer working, is it placed somewhere else? Also, can you say where your CG is placed when you have pontoons? Most others say the CG from the manual is too far back. I have one recommendation for moving it 1/4" forward.

harrymc
05-07-2007, 08:01 PM
I checked the link and it still works for me. I use Windows media player to watch the video, is that what you're using? PM me if you're still having trouble viewing it. Is anyone else having trouble viewing the video?

Harry

Hal-i-chopter
05-07-2007, 08:20 PM
I checked the link and it still works for me. I use Windows media player to watch the video, is that what you're using? PM me if you're still having trouble viewing it. Is anyone else having trouble viewing the video?

HarryHarry, Apparently my company firewall is blocking me from downloading your video. I tried using a non-company computer outside of the firewall and I can download it OK. I tried navigating to your website in case you moved the video and I don't have permissions to get in. (this happens on either computer).

Anyway, I have a couple questions as another Cub pontoon flyer.

1. With pontoons, where is your CG located? Are you happy with it? How did you get it there (i.e. add weights, batteries as far forward as possible etc.).

2. I am getting very bad spraying of water with the recommended propeller. I notice you got some too. What propeller do you use? I tried a smaller higher pitch prop and I couldn't get off the water but that was probably a different reason.

3. That was a nice landing in the video. It looked erratic at first but I guess you were bleeding off altitude and speed; you flared nicely and kissed the water without bouncing. I have trouble bouncing back up in the air with flaring and then landing hard, or also just bouncing off the water. Any tips on landing without bounces?

Skyburner
05-09-2007, 12:22 AM
Hello all, i'm new to this forum and I'd like to say Hi. I'm curious if anyone has ever built or seen the j3 cub from hobby-lobby. It seems bigger and certain parts like the bungee on landing gear etc. seem better made. Here's the link. Any help would be appreciated. http://www.hobby-lobby.com/j3cub.htm

Solid Hit
05-09-2007, 01:54 AM
Welcome to WF

Looks like a nice plane. I'm afraid I have no experience with it but Hobby Lobby is pretty good about picking planes to sell. Besides how wrong can you go with a Cub?

Hal-i-chopter
05-09-2007, 02:35 PM
But does it have a pontoon option? :ws:

I love my pontoon setup.

Skyburner
06-06-2007, 03:02 PM
Hi, I just posted this in the parkflyer section but I'm thinking it should probably go here. Anyways....

Hi,
I just built and maidened my eflight .25 J3 cub. I love it. It's my first "real" plane as my LHS put it. I self learned on a hobbyzone supercub. I was wondering if the large J3 can be hand launched the same way as the supercub can. Also, since i'm fairly new to this sport, any tips on landing these tail draggers would be very helpful. I've had 4 successful flights but i'm looking to make the landings a bit smoother. :red: I fly at a soccer field with short grass. Any help would be appreciated.

Hal-i-chopter
06-06-2007, 03:29 PM
I always had problems landing in grass, the Cub would roll OK at first touchdown but inevitably nose over at the end. I bought some bigger diameter wheels. But I now use pontoons 90% of the time, much more fun! I have also found a huge improvement putting my CG about 1/4 inch more forward than the instructions say. When I had CG at the midpoint of the instructions I would porpoise easily upon flaring. Now when I flare it is easy to keep it on a straight level slow landing.

If you are new to the Cub be very careful of stalling and stall spins. I have crashed 4 times due to these. Keep the speed up until you flare for the landing. There is a lot of discussion of how to improve the stall characteristics (like differential ailerons).

SilberIgel
06-06-2007, 04:32 PM
The trick to flying these beauties is to maintain your airspeed. The full scale cruises about 65mph, flies approach about 55/60mph and stalls at 38 or 40mph. You don't have a lot of margin with these planes and getting slow at low altitude invites trouble. Your model is the same....

And, they are 'rudder' airplanes.... you need stay on top of the rudder.

IME, best landings are made by setting up a stabilized glide using the power to control the rate of descent. With my J3 and the Power 25 system, its about 1/3 throttle. You want to "fly" the aircraft to the ground .... do not try to flair it..... let it descent till the mains just touch the ground...keeping the power on!!! ..... EASE back the power and she'll settle in and as the tail settles to ground pull up elevator... slowly! You want to land the mains, the tail, then 'stick' the tail on the ground so you have full control.

She's gonna look like she's screaming along as it gets close to the ground but you need that airspeed to maintain rudder and elevator authority.

Skyburner
06-06-2007, 08:21 PM
Thanks for the replies. I've been trying to land it like the supercub. Basically no or very little throttle required with that plane. However like you said, I think i need to keep my speed up. This plane does handle different then the foamy version that's for sure. I'll try today with about 1/3 throttle and see how she settles in. As for the floats, i just picked them up and should be able to fly at the lake within' the next week or two. No water around the house but the cottage has lots!!!

SilberIgel
06-07-2007, 03:48 AM
Sky,

Be sure to read the handbook before flying the Cub with floats. There's several pages on how this plane handles when on floats.

One thing is for sure....if you learn how to fly a Cubbie, you will be able to fly just about anything. Maybe that's the reason why so many great pilots started out in J3s????

Skyburner
06-07-2007, 03:50 AM
Thanks again.....
Any ideas about hand launching the cub (with landing gear attached). Is it possible or does the plane not have enough ground speed to get enough lift with a hand launch?

SilberIgel
06-07-2007, 02:45 PM
HLing may be a problem. Mine weights 4 lbs and appears to have plenty of power for normal flying. Its power to weight ratio is NOT as good as an fully aerobatic or 3D plane that can pull itself up by its bootstraps from a hand release.

You won't have continuous control when HLing. Getting your launching hand to the stick quickly enough is the first issue. Getting things under control without over cooking it is the second. I'd not take a chance pranging my beautiful Cub with a HL. ROGs with the J3 are not difficult to master and I'd stick with those.

Aussie E-Flite
06-07-2007, 03:07 PM
I agree with SilberIgel. Handing launching the E-flite can only end badly. It is a magic little machine to fly, and at the end of the day it is a 'scale' model and so it should be flown ROG. Yes, it can a bit of trick to master, but as has been said before, will make you a better pilot in the long run.

compflight
06-19-2007, 09:34 AM
Thanks for posting the video.
Guess E-flite should be happy too with all those extra sales now a comin.

RacerPaul
06-22-2007, 01:20 AM
Sky... great job and great video!

Paul

Glacier Girl
06-22-2007, 08:09 PM
Dang, late to the party again. I love my Cub. I too fly off a rough soccer field. To help the take offs and landings I built mine as a bush plane. Tundra tires, hand built bungee system, and went with the 32 motor instead of the 25. Mine spins a 10 x6 wood prop and it's more then enough power for those rough field short take off conditions. Only really two problems I've run into. #1 Mine seems to really float on landing, even with the prop barely ticking over she just wants to keep going. Hmm maybe it's not a problem. Anyhow, something you should watch for, if you land a little too hard she's going to spread her legs, so to say. The LG will fold out and you'll have to do some reworking to make it right again. Hence the bungee system on mine. Simple to build. One heavy control rod, a pair of stiff springs, and couple of pieces of heat shrink. I loop one piece of wire around the main gear at the wheel, the other wire goes to one of the LG screws. I put a hook end on the unattached ends of the wires, connect the spring to them. Cover the spring with a piece of heat shrink and it looks like the bungee system on a real one. Well close enough.
Here's a pic of her before I added the bungee, and one of the tire differences.

Glacier Girl
06-22-2007, 08:17 PM
Knew I had a pic of the bungee set up somewhere.
Pic #1 is the spread leg version Cub (not mine)
Pic #2 is the bungee set up, springs allows the gear to flex, but pulls it back into place.;-)

Hal-i-chopter
07-17-2007, 05:13 AM
Thanks for the replies. I've been trying to land it like the supercub. Basically no or very little throttle required with that plane. However like you said, I think i need to keep my speed up. This plane does handle different then the foamy version that's for sure. I'll try today with about 1/3 throttle and see how she settles in. As for the floats, i just picked them up and should be able to fly at the lake within' the next week or two. No water around the house but the cottage has lots!!!
Float flying is great. I have been doing a lot of flying off of the dock on our lake. Lot's of people commenting and asking questions. The last time I went into my LHS the owner said I was responsible for at least 5 sales of E-flight Cubs with floats from his shop. (then where is my commision???) :)

I race sailboats on lakes in MN and when we have regattas there is always at least one day with no wind part of the day. That is when I bring the J3 with floats. It is a big hit with the (bored) sailors waiting for the wind to pick up and the races to begin. The perfect complement to sailing, when one tanks the other is perfect. :)