J-3 cub engine direction
 

Hi,
I am new as you can guess.

I am building J-3 cub 48".
I am at the point of mounting the engine.

The engine is mounted a little on the left of the plain's center line.

My question is:

Should the engine point paralell to the center line or should it point a little bit to the right?

Thank you.

J-3 cub engine direction
 

First and for-most, do what ever the directions tell you to do! In most cases if the directions do not say anything about the thrust angle it should be set to 0-0, or 0 degrees down and 0 degrees left or right. In some cases the kit will need some down and or right thrust to the engine, 1, 2 or 3 degrees is common. This helps offset the left turn tendency of the aircraft.

In short the answer is... if the directions don't tell you do do it, don't. mount that sucker straight on! After you fly it for the first time, if you want to play with it go for it, but first try it the way the manufacturer recommends!

J-3 cub engine direction
 

Thanks.
Thats what I did.

The directions mention it had right angle trust and they said to mount it as the mount rails were directed.

Thanks again.

J-3 cub engine direction
 

Another question:

The directions said to use only 2 of the holes in the tank -
1 for the engine and 1 for the muffler.

So, how do I fill the tank with fuel then?

J-3 cub engine direction
 

I think that you will find that 3 or 4 degrees of right thrust will be needed to help over come the torque of the engine , unless it is already built into the firewall,

read all the information that you have with the kit ,if it is built in it should be stated somewhere in the information,

let us know what you find ,

Highlander

J-3 cub engine direction
 

You will fuel the tank thru the line to the carburator, unplug it and the line to the muffler , pump fuel into the one that was connected to the engine until you get fuel from the one that was connected to the muffler , reconnect lines

Highlander

J-3 cub engine direction
 

Thanks.

I will look for some T-connector ... ;)

J-3 cub engine direction
 

I usually put a filter between the tank and the engine , its simple to diconnet there and hook to fuel supply

Highlander

J-3 cub engine direction
 

Many highwing kits and ARF's have the firewall installed so the down and right thrust are provided for when you install the mount. Because of this the crank shaft will protrude out a scale cowling to far to the right so the mount is slide over to the left a bit so the prop shaft will be centered in the cowl but still be angled and provide right thrust.

John :)

J-3 cub engine direction
 

Pla,
First, welcome to RCU and the wonderful world of RC flight. It's a great hobby, and there are a LOT of good folks involved, both here, and at local clubs.

One thing that hasn't been mentioned yet, make sure you find an instructor to help you learn to fly!

Cub's are not the easiest planes to fly at it is, and being new will mean "re-kitting" without help. (ie. That Cub will go home as a pile of sticks.)

Go to the AMA website. They have a spot that will help you find clubs in your area.

http://modelaircraft.org/templates/ama/

Dennis-

J-3 cub engine direction
 

Thank you all for the replies.

Thanks for the explanation.


That sounds a good idea. I would need access to the filter anyway.

J-3 cub engine direction
 

Don't worry...
somebody just stepped on it - on the stabilizer/elevator... :cry:

I couldn't find any replacement ...

Anybody has a horizontal stabilizator and elevetor for Global J-3 Cub 25 ARF .20-.28,48" ?

Or what do you usually do in such case?
Open it up, see the construction, buy some wood, and do it yourself?

J-3 cub engine direction
 

I just found this link:
http://globalservices.globalhobby.com/part/12366401.asp

This should do...

J-3 cub engine direction
 

Pla,
It SHOULD be pretty easy to repair, but from what you are now saying I'm assuming thst the Cub is an ARF. If so, you will need to buy wood, covering material, and a covering iron at least.

J-3 cub engine direction
 

AHHHH Geeeeeze PLA

sorry to hear that your plane got stepped on !!!!!



fixing it is not a problem, try and get the tail feathers from global, or if that is not possible , then you will need balsa , covering , and CA glue and some epoxy, either a covering Iron and heat gun ,if you cant get both get the Iron, and then a little patience and time it will be good as new ,

then, find a nice corner of a bedroom, or garage , make a couple of loops of soft rope and hang your plane from the ceiling ,

If I was there we could fix it in a couple of hours , but if you need help, many folks here build and are more than glad to help long distance , may even be some in your area , keep us up to speed ,

Highlander

J-3 cub engine direction
 

I ordered a replacement stabilizer set.
It should be here tomorow. :D

Now, any advice on removing the broken stabilzer?
It was glued with epoxy. I asked in a store and they said there is no disolver for epoxy (only for CA).

I will try to split it with knife but somehow don't feel it will work well... I am afraid not to brake the body.

Or I can brake out the stabilizer and pile the epoxy...

J-3 cub engine direction
 

It is completely fixed! :D

Thanks for the help.

J-3 cub engine direction
 

COOL!!!!!!

feels good dont it to have fixed it good as new,!!!

Highlander

J-3 cub engine direction
 

i have never had any problems with the full scale cub i have flown ;) it flew much better than the Super Decathlon i fly.

J-3 cub engine direction
 

BR

I think as you mature into the Sport/hobby of RC flight that you will come to realize that in the case of some aircraft such as the cub what may work well in the full scale world for a given task is not necessarily the case in miniature. In fact Cubs for RC of literally hundreds of designs, most have been somewhat challenging to fly and make rather poor trainers for this reason.

This is due in part to the fact that it is a high wing, high drag aircraft with a high aspect ratio wing and large barn door ailerons that provide considerable adverse yaw that must be corrected for in flight to keep that airplane from wallowing around like a sick whale. To fly an RC cub well requires considerable skill. The fact that you have flown a full scale cub will in no way prepare you to fly an RC cub. As a matter of fact The mechanics of flying any RC aircraft (I am not talking about Wx, regs or navigation) is more of a challenge than learning to fly full scale.

John

J-3 cub engine direction
 

oh, thanks for the info. :drowning: i will probably do that when i try out my SD :(

J-3 cub engine direction
 

Oooohh boy...
So many things to think of on the first flight... now one more - yaw ...

Anyway.
Do you measure the control throws at the end of the elevator, ruder,...?
It seems very little to have only 1/2 " for high rate for the elevator...
Just wanted to make sure I am measuring corectly.

J-3 cub engine direction
 

i measure from the ends at the farthest place out

J-3 cub engine direction
 

Pla, Yes measuring at the widest spot will work fine. For a 48" cub (you never really said which one) Half inch throw on elevator even for high rate is too much and it will be a handful. Do not use more than the plans suggest for either hi or lo rates and if you error do it on the low side for all the surface's.

This is the most common error the newbie makes on arrival at the field And more time is lost for this reason than any other perhaps even being unable to fly on that day. Most people use reasoning that goes something like this: "I want all the control I can get" well this is opposite of what is needed. Yes, on rare occasions there is not enough but this is almost never the case.

Welcome to the adventure.

John :)

J-3 cub engine direction
 

JohnBuckner , has given good advice , I agree with it ,

Highlander