Fine Tuning ARF

I could use some basic set-up info like overall weight, line rake, tip weight, handle spacing and, most of all, elevator and flap travel. I'm not sure I hooked up the push rods to the right control horn holes.

I think I could shorten the nose. It would get into manuvers slow then turn real tight so, I moved the engine and tank back and added tail weight. It balanced 3" back from the LE which improved it alot.

It also has a rather sharp LE. Is this the way Windy designed it or, was it too labor intensive to round it off?

It's darty like it has a mind of it's own. It's hard to get it to go where I want it to go. It's easy to over control and stall in manuvers like it has too much travel or, is too fast on the controls. The elevator goes 25 degrees up and 30 down with the push rod in the middle hole on the elevator (I guess they made the primary push rod too long). I'd like to try the longest hole on the elevator horn but, will this give me too much flap and not enough elevator?

It came with a small wing warp. I tweeked the flaps but could still see the top of the wing in flight. I twisted the wing and tightened the monokote but went a tiny bit too far so, I tweeked the flaps the other way (quick field fix). If there's any wind the wings seem to jump around alot on the roll axis, if that makes sense.

I can see the bottom of the wing during inside loops and, It gets real light on the lines at the top of outside loops even with good air speed.

At this point I feel like the plane is flying me. Any help for a rookie?

See Ya

Tony

There is certainly nothing wrong in this--I am assuming a mild tweak of course!

Well, if you need tip weight, then tweaking won't help. But if you need to tweak it, you need to tweak it. I don't know who "chewed you out" - but they had better come "chew me out" too, since I have absolutely no compunction about it.

The wider the handle spacing the jumpier the airplane is going to be. And the better you get, the more sensitive you will get to this fact. I always recommend getting a good, adjustable handle. This is a life time investment, and having more than one handle for more than one plane is also a good idea. Then set up each handle for the plane you are flying.

Now, what was mentioned above in the other posts is good advice. You want enough tip weight so the plane flies level upright and inverted or with the outer wingtip "slightly" down (to begin with). Set the center of the leadouts about an inch behind the center of gravity to begin with. Adjust from there (small increments at a time.) Whenever you make an adjustment, see if it helped or hurt. If it hurt go back. If it helped, this is your new "square one." Unless the set up is a mess, do one adjustment at a time, and do not be afraid to fly straight and level just to fly it out if someting is wrong. One of the biggest causes of crashes is people doing things they shouldn't do before they get the plane in proper trim.

What kind of handle are you using, by the way, and what is the handle spacing?

If I want to limit the travel of the controls, is it ok to put stops on the push rod that will hit the fairlead or, should I put stops on the lead outs?

I guess it would de-sensitize and reduce travel if I made longer control horns for flaps and elevator.

Must get new lines. Part of the problem might be I've been flying on .018" lines. Is there a big difference with .015" lines?

Just get a stunt handle. Ted Fancher's handle or Tom Morris' handle would be dandy. You might order a set of lines from Tom, and take care of both issues with one check. No point to making new control horns at this stage. Print out the trim flow chart that Tony posted! Steve

What engine and prop are you running ? The two cardinals I have seen at my club are both running LA 46's and both pilots really like their set-up. You need .018 lines if you are running a 46. .015 lines are for .40 or less. Sometimes a bigger prop (like a 12-4) on the LA 46 can help stabilize a plane similar to adding tailweight or narrowing the handle. I run a Zinger 12-4 on a LA 46 on a custom built profile similar the Cardinal in Size and really like that setup.

Edit: The other thread (I can't find) is "NVA Range" Topic #11109

"To add a bit more data - I went home and checked the prototype for some numbers.
Regarding push rod locations:
Inner hole on bellcrank to middle hole of flap horn.
Upper hole on flap horn to upper hole of elevator horn.
Other factors
Balance right at aft edge of L/E planking
About one-half ounce tip weight
Around one degree engine offset and a bit more on the rudder.

(added today - I forgot to mention the leadout guide position. I hung the plane by the leadouts and set them such that the nose was just barely pointing downward - maybe 2 or 3 degrees.
Approximately 1/4" total elevator free play.
Also, I have decided to leave the OS .40 4 stroke engine in it. It is a perfect setup for the flying I like to do and it's unbelievably quiet. )

I repeatedly brought the prototype to the field and left it out for anyone and everyone to fly - it was flown by everyone from beginners to top level experts. There were days when it flew continuously for three or four hours. Most of the flights were with the LA .46, on 63 foot lines, Hot-Rock handle. We also flew it with an ENYA .45, a Brodak .40, an OS .40 4S, and a Magnum .40.
I did the same at the Brodak Fly-in - offered it to anyone wanting to enter it and many took me up on it - It did quite well.
The most prevalent suggestion was to add more tail weight.
Hope this helps.
Bob Z.
ps - how about some others sharing experiences and suggestions."

I drilled the control horn out but didn't know how far to go with the free play. I'll check that today.

I guess the push rod connecting the flaps and elevator should be in the same control horn hole front and back for a 1:1 ratio. Mine is in the middle hole on both and, the push rod from the bellcrank is in the top hole on the flap horn. The only difference I can figure is my set up is less sensitive with less travel which I like. Even so I have at least 25 degrees travel each way which is too much with my hot rock handle. Maybe the prototype has a larger bellcrank than mine.

My LA .40 has been lightened by about 1 ounce, I use a wood prop and a tongue muffler, 3 ounce tank and, everything is pushed back far as it will go. With a little tail weight it balances the recomended 3" back from the leading edge with no fuel. Either I have the lightest ARF Cardinal ever made or, you guys are adding alot more tail weight than me.

I'm going to a standard muffler, a 4 ounce tank and a plastic prop. I don't want to add lead to the tail so, I'm going to shorten the nose about 3/4".

Hope the wind dies down for Sunday.

For anyone building this ARF, I suggest going all over the wing with an iron. The covering on mine keeps comming loose in different places.

I made up a fiberglass pushrod with a piece of the ARF-included 3/32" rod and a 4-40 Hanger9 Ball Link on the Elevator end so I can adjust relative neutral. I've read that the Rocket City Ball Link is superior but can't find them. This pushrod goes outer flap horn to outer elevator horn.

The only other change I made was to use Monokote hinges rather than the Mylar/CyA hinges supplied.

Without engine/tank/prop/spinner, it weighs 31 oz., and I have no idea how this compares. Total dry weight should be around 43 oz. with a Brodak .40, and ought to perform at least OK.

It's curious, but I need to put 1/16" shims under the engine to center it in the nose ring. Anyone else noticed this? Should they have been supplied parts?

I've never used a ball link, how do you get free play in the elevator?

I just cut my nose ring off. I guess I just don't get the whole nose ring thing, what are they for?

Yes, moving the primary pushrod to the middle hole makes the controls faster and increases throw. With the pushrod in the outer hole, there was only about ±15° of deflection, which seemed way too little.

>I've never used a ball link, how do you get free play in the
>elevator?

My first time with a ball link. Right now, there's no free play. If it seems necessary, I can ream out the hole in the flap horn end a bit. BTW, don't try to put the ball link at the flap end; there will be interference with the primary pushrod which will limit deflection. Guess how I learned this!

>I just cut my nose ring off. I guess I just don't get the
>whole nose ring thing, what are they for?

Well, on a full-bodied plane the plywood ring gives you a hard surface to finish and flair in the spinner. I presume the same purpose is served with a profile. And I had to epoxy mine back on, 'cause it was broken off in transit.

Anyway, I did some checking and found I've got about 2 degrees of in thrust. I had the engine pushed all the way back in those funky motor mounts. this made them squeeze the front more than the back due to flexing of the clamping bars. Also easy to get up or down thrust if you don't check it before torquing. These things just barely hold the engine tight enough, I'm getting rid of them.

Darn, windy again today.

Giffy,
That sounds good to me. I set mine up at 1 to 1 top hole on the flap gives me 30 degee flap travel, more than that is not beneficial.

Well I took the plunge and cut 3/4" off the nose, cut out the spreader behind the engine and moved the engine all the way back. I added a plastic spinner cone and, a friend found a nice 11-4 rev-up wood for me. With a larger (4oz) tank it balances just right with no tail weight.

Originally I thought I could move the engine back enough to use the OEM muffler but, can't get it back far enough and have room for the tank. Wow, that muffler weights 3 ounces so, I have to use the tongue muffler to make it fly right.

Also got rid of that innovative motor mount and went with through bolts and blind nuts. Those mounting straps were pinching the engine bearers more in the front and giving me in-thrust! I added some of those plastic strips to give it 2 degrees of out thrust.

I set the lead outs 1" behind the CG as suggested. I got some .015" x 65' lines and a good handle from Dick Byron.

Wow, did this plane come to life, it flys great. It's amazing the little things that make a difference. I can honestly say now that the pilot is the limiting factor.

The only thing I need to know is how many flights can I put on this thing before I start to worry about the leadouts breaking off the bellcrank? I've got about 20 flights on it so, far.

Thanks to all who helped, can't wait for Brodaks next year.