Sig 4 Star Hardware

[chadtheguru]

I'm movin up! I'm going for the 4-Star. Is the hardware package sufficient? Should I get ball-links and solder clevises?

[indoruwet]

I do not know what the packaged stuff contains, but I do have some rules for my self.

Clevises. I only use the metal ones. I just do not trust the plastic ones.
Control rods. I check if the ones supplied are stiff enough for long distances.
There is a lot of inferior stuff floating around. Because of that alone, I do change the mounting of the servos for the rudder and the elevator to "as close as possible to the back of the plane" on most of my planes.
I always use a "Z-Bend" on one end of the control system. No need for two clevises, one on either end. The clevis goes on the end where I can get to when the plane is fully assembled.
I ONLY use the "Golden Rod" system on a throttle set up. Those plastic rods tend to shrink or expand with temperature (I think!!), plus the fact that when you use those rods, you HAVE to support them somewhere half way for long distance set-ups. I can deal with that on a trottle set-up.

Ivanc knows all about the 4 star units.

[ivanc]

In my 4*40 ARF I used the hardware supplied with it and did not have any problems. It has a relatively small surfaces that do not generate excessive forces. So for me the nylon clevices and pushrods worked fine.

In general I try to use the hardware privided by the manufacturer, UNLESS some of it is obviously inadequate (usually most vietnamese and some cheap chinese ARFs). If a component fails I'd replace it with a good quality one (DuBro, Sullivan, etc.)

Ivan

[chadtheguru]

Any suggested mods while building? Weak areas that need work such as where the wings bolt down?

I know the 4* is a great model. I'd really like to exploit the experience of some of you veteran builders and do it right the first time.

Thanks again, btw :)

[chadtheguru]

Oh yeah, and prop suggestions for an OS 46AX. I plan on doing lots of aerobatic sorta stuff. You know, feeling out the non-trainer :)

[ivanc]

The only weak point that I had with my 4*40 was keeping the tail LG hinge in the tail - it kept working itself loose until I pinned it - after that it never gave me any trouble.

You can see pics of my 4*40 here (http://bulgaria21.com/modelairplane/sig4s40.html).

Ivan

[chadtheguru]

Did you put the canopy on backward?

[indoruwet]

Did you put the canopy on backward?
Chad !!!!! :confused:
Has the hurricane season affected your perspective capability ..... ?? ..... :eek:

There is NO way at all to mount that canopy backwards !!!

[chadtheguru]

Ivanc's canopy looks a lot slicker than the stock picture on tower's site. The stock picture looks all bubbly.

[trab1925]

I do agree, it does look some what different than mine. His comes down a bit faster unless he cut off more to make it look like that. You can see mine here... I just got it broken in and can't wait to fly in Tuesday.

http://www.rcgroups.com/forums/showthread.php?t=526734&page=4&pp=15

Finished pics are on page 4 and construction pics are pretty much every where else. I don't think I'm going to put decals on it because I like it just fine. I don't know if it's just how I covered mine with the black on bottom but it kinda looks like a Piper PA-25 except canopy is a bit different.

[ivanc]

Yes, I cut part of the canopy and put it backwards. It looks slicker IMO. :D Good catch, Chad!

Ivan

[Dave Gardner]

Here are photos of my son's 4-star 60 which we built last winter. Heavily modified....

[indoruwet]

Dang ..... I stand corrected !!!!

[chadtheguru]

@indoruwet:

:P

[chadtheguru]

The only weak point that I had with my 4*40 was keeping the tail LG hinge in the tail - it kept working itself loose until I pinned it - after that it never gave me any trouble.


Ivan, how did you pin the tail wheel? My best guess would be drill through and epoxy a toothpick or a tiny dowel in there. What did you do?

[ivanc]

I drilled and epoxied a short piece of pushrod wire - a toothpick will break. That is the same technique used to pin the control surface hinges (the plastic or metal ones, not the CA hinges). Clean the wire with acetone or alcohol (rubbing or denaturated) before even inserting it in the pinhole - you don't want any oils in there. ;)

Ivan

[chadtheguru]

OIC :) And in the course of assembly (after the wing is assembled), the instructions ask me to mount the wing onto the fuse. Is it supposed to be difficult? The torque rods on the wings were very much in the way. Is there an easier way to get it on there?

[ivanc]

Mounting the wing to the fuse is a simple task - I did it with my 4*40 every time before flying it as the plane did not fit in my car with the wing attached to the fuse. The aileron rods should not be in the way. I can not picture it in my head - can you take and post pics?

Ivan

[chadtheguru]

No camera :( (maybe for my birthday coming up soon :D ) I'll try to explain it, although it may be as simple as the ailerons not being trimmed up yet.

I slide the LE into the fuse making sure the big tab thingamabob is in the slot. When I push the TE toward the fuse to bolt it down, the torque rods hit the fuse. I've gotta push em in to get them to go into the fuse so I can bolt the wing down. Does that make sense?

[ivanc]

Gotcha! :) Yes, on the 4*40 the ailerons have to be centered for the rods to clear the back of the fuse. If they are both down it would be hard to clear the fuse or they will barely clear it. Also if you have not aligned the ailerons properly and they are slightly down the plane would tend to float and baloon more on landing - the ailerons will act as flaps. The plane will also have more coupling - something observed in KE. Use the provided template (made of plywood) to center the ailerons - it DOES matter whether you use it on top or bottom of the wing - read the manual carefully as I don't remember exactly where it should go.

Ivan

[Daverp]

I had the similar problem when I first put mine together. On mine once the ailerons were aligned the rods would clear but the plastic horn screwed on to them was hitting the fuselage and keeping it from fitting. Screwed the horns down a 1/4 inch, re-aligned and the wing fits on with little fuss. Might want to give that a check.

Dave

No camera :( (maybe for my birthday coming up soon :D ) I'll try to explain it, although it may be as simple as the ailerons not being trimmed up yet.

I slide the LE into the fuse making sure the big tab thingamabob is in the slot. When I push the TE toward the fuse to bolt it down, the torque rods hit the fuse. I've gotta push em in to get them to go into the fuse so I can bolt the wing down. Does that make sense?

[chadtheguru]

Thanks. I looked to see if I had missed a step by not aligning the ailerons yet, but I'm supposed to do that later. It must be because they are'nt aligned yet.

If they still hit the fuse, I'll do what Daverp says. Thanks for the help guys!

[ctdahle]

The horns are bent with an offset to give you differential. Are you sure yours are installed in the correct direction?. I do not recall any binding happening on assembly with either of my four stars.

Be that as it may, installing individual servos out in the wing is a nice mod for the 4*.

Somewhere else on this board, in the last week, I posted a long list of 4* mods, but I'm too tired to look for them now.

[fhhuber506771]

The issue with the aileron horns being causing problems getting the wing on is why I chose to pull the single center mount servo... open the servo mount hole a bit... and drop in 2 servos using 2 of the original servo's mounting screw holes for each of the pair (still 4 screws per servo...)

Dual servos fit... on a Y cable or 2 doifferent channels for "flaperons" you can deflect BOTH ailerons upward by hand gaining easy clearance when putting the wing on. The added weight is insignificant for the model....

Just a simple cheap (1 extra $10 "standard" servo) way to get past an aggrivation.

[chadtheguru]

Somewhere else on this board, in the last week, I posted a long list of 4* mods, but I'm too tired to look for them now.

Is this it? (http://www.rcgroups.com/forums/showthread.php?p=5894980#post5894980)

[chadtheguru]

open the servo mount hole a bit... and drop in 2 servos using 2 of the original servo's mounting screw holes for each of the pair (still 4 screws per servo...)

Did you install them side by side like this?

http://static.rcgroups.com/forums/attachments/9/3/9/2/2/a954643-225-servo_arrangement.gif

[ivanc]

That's how I installed them on my Super Sportster. But believe me, the 4* would not benefit from a dual servo setup.

Ivan

[chadtheguru]

Quoted from another thread:

It's got a big wing and at sea level, the complaint is that it floats and is hard to get down on the ground. I don't have this problem at 8000 feet, but some suggest that cutting off one wing bay from each tip makes for a more responsive and hotter airplane.

My field is at an elevation of 42ft. I have had a hard time with my Eagle 2 getting it to descend and flare properly. Would cutting off a wing bay help? Is this possible with an ARF without having to re-cover the wing?

Also, I know you said the 4* wouldn't benefit from dual aileron servos, but would flaperons help at all in slowing down enough to descend? (Please be gentle. My understanding of this kinda stuff is pretty vague.)

[fhhuber506771]

That's how I installed them on my Super Sportster. But believe me, the 4* would not benefit from a dual servo setup.

Ivan


Flight performance wise... you are correct. I "played with" the flaperon and spoileron functions... eventually went to a Y harness simply because the added functions didn't help the plane do ANYTHING

You can experiment in flight with different "neutral positions" of the ailerons if you have flaperon/spoileron mixing... because of minor variances n construction you may find a tiny amount one way ot the other from the recommended neutral which gives slightly better overall flight performance. (my final setting was 1/32 inch up at TE of root of aileron vs the lazer cut alignment guide piece)

Ease of putting the wing on.... it does help.... and is the only real reason to do it. (for the Four Star... other planes differ)

[fhhuber506771]

Quoted from another thread:



My field is at an elevation of 42ft. I have had a hard time with my Eagle 2 getting it to descend and flare properly. Would cutting off a wing bay help? Is this possible with an ARF without having to re-cover the wing?

Also, I know you said the 4* wouldn't benefit from dual aileron servos, but would flaperons help at all in slowing down enough to descend? (Please be gentle. My understanding of this kinda stuff is pretty vague.)

Before clipping the wing (major airplane surgery) Try a longer lower pitch prop.

Cheap, quick, easy.... and easy to reverse if you don't like the result. (unlike clipping the wing)

*************

I have never seen or heard of annyone using flaperon function on an Eagle-II...

It shouldn't hurt to try... but it may help... it may hurt... it may do pretty much nothing at all. (for example on the 4* flaperons just alter the elevator trim a bit with no appreciable performance change even with relatively high deflection...)

[chadtheguru]

My field is at an elevation of 42ft. I have had a hard time with my Eagle 2 getting it to descend and flare properly. Would cutting off a wing bay help?

Wow, my communication skills took a break on me...

I meant the Eagle 2 had to be waaaay slow to descend and the flare almost always made it climb (it didn't have flaps). The 4* will likely behave similarly. Would cutting a wing bay out of it or using flaperons help?

Sorry bout that

[fhhuber506771]

no problem... I knew what you meant basicly...

Try the different prop. Its easy.... Its quick... its easilly reversed.

Go ahead and try the flaperons (and spolierons) Might help... might not. Its easier and quicker than clipping a wing... and you can go to a Y harness (or program for no flap effect..) if the added functions don't enhance the way the model performs.

Clipping the wing is the LAST option to try.

**********

With a large lightly loaded model (4* and the Eagle-II) the prop can potentially produce enough thrust at idle to keep the thing flying in ground effect for as long as the engine is running.

Les pitch at the same rpm = less tendancy to "float on by" the runway. You can get the Pitch speed at idle below the minimum speed to hold the plane in the air and the prop becomes a brake rather than providing forward thrust.

Plus.. added bonus... better rate of climb. Sometimes better top speed (if the original prop was a REALLY bad choice for the model)

[ivanc]

I recently (today or yesterday) posted about the effect of flaperons and spoilerons on a 4* (I experimented with a Super Sportster, but the flaperons/spoilerons will have similar effect on the 4*). I'll search for the post and copy the text here.With planes like the Pulse (also the 4* and the Super Sportster - I experimented with flaperons/spoilerons with the second) you do not want the ailerons to act as flaps on landing - although they induce drag, they also increase lift and close to the ground the plane has even more tendency to float and baloon than when the ailerons are centered. These planes do not need flaps - they are small enough and the way they are designed they do not benefit from using flaps. What might be more useful is raising both ailerons up - which is called spoilerons. Spoilerons increase drag while reducing (spoiling) lift - exactly what is needed with planes that tend to float and baloon at ground effect. As a result they bounce less or not at all at touch down.

To set up spoilerons use the flaperon mix but program on a switch anything between 15% and 35% of up travel for both ailerons - such mix is usually called "landing" or "camber" mix. Just flip the switch on the downwind leg when the plane is still at safe altitude and fly the plane at around half throttle while turning upwind to line up fith the runway. Keep in mind that you most likely will have to use more throttle on the landing approach with the spoilerons deployed to compensate for the increased drag and decreased lift.

Ivan


Ivan

[fhhuber506771]

Spoilerons (as applied to the dual servo application using the original ARF/kit ailerons) themselves don't increase drag that much until you get to rather extreme deflections.. What they do is force you to raise the nose of the model to compensate for the effective alteration of the airfiol from symetrical to an inverted underchamber. Very similar to flying a flat bottom airfoiled plane inverted. (in some respects)

"Presenting the belly" of the aircraft to the direction of flight... the entire model is one big airbrake. Spoilerons let you do that without creating as much lift as you would if you didn't use them.

Small deflections (usually under 10 deg) you are more altering the airfoil's lift than anything else. Large deflections (usually over 30 deg) can have the control surface "make more drag than lift" Somewhere in between is the point where you are crossing over.

Most sport flyers applying flaperons or spoilerons to a 4*40 or similar find that by the time you hit the "more drag than lift" the ailerons don't seem to work right. (especially when doing flaperon... and that is a predictable result.)

*************

Mainly saying mostly the same thing as Ivan in a different way.... But some people will understand one explaination better than the other.

You like mine better... fine. You like Ivan's better... thats good too. The point is to attempt to make it understandable to as many as possible.

[propsmasher]

Okay, so what is a good prop for the 4* and an OS46 ? Suggestions???

c

[fhhuber506771]

try: 11X5... 11X4 12X4 12.25X3.75

You may like the 11X5 better... may like the 12X4 better... My pref would be 11X5

My bet is you currently use 10X6 or 10X7.

12.25X3.75 will almost hover it... but the tail is too far back to be able to blow enough air over the tailplanes for the control to keep it in the hover. It will accelerate in a vertical climb from the attempt though.(If you "pour on the coals" before it flops over)

[chadtheguru]

I've been using 11x5 :D

[fhhuber506771]

try the 12X4 then (or tune the engine for a slower stable idle...)

Its all about the pitch speed at idle turning the prop into a brake. Lower rpm or lower pitch, it slows the plane down.

[ctdahle]

To all of the above, I would just add this: A prop with a flatter pitch will slow it down as stated by others. With dual servo set up, you could mix spoilerons to the last say 1/8th of the throttle throw. You can set up your linkage so that the last 1/8th of the throttle servo throw has only a tiny effect on the engine, but moving the stick will cause the spoilerons to kick up when you pull back the throttle the last nth, which you would do at touchdown to kill all the lift and firmly glue it down to the runway.

The other thing you can do is quit trying to do a full stall landing, but rather, come in hot and paste it onto the runway. On the four star, this means doing a wheel landing and having the nerve to keep the elevator at neutral, or even pushed a bit forward as you touch down and roll out. Takes nerve to do it the first few times, but once you have it nailed, you'll always land this way.

On the Eagle, you can do the same thing. Just fly it on to the ground and neutralize the elevator at touch down. You can make your job a lot easier by putting on oversized main wheels so the plane assumes a nose down attitude when it's resting on all three wheels. This means that as soon as you touch down, the landing gear is helping your wing generate "negative" lift that hold the wheels on the ground and slows the plane down quickly.

And for all you skeptics out their, I was skeptical too until the full scale CFI who told me about this took me up in a Cessna 180 and showed me.

[ivanc]

I had an 11x6 and liked it. I don't like low pitch (4") props on anything that does not have a really thick airfoil. You may also want to try a 12x5 - will provide more vertical than the 11x6. The 11x5 might be OK too - just try different props and see which one will match your style of flying the 4*.

Ivan

[fhhuber506771]

Full throttle touch and goes can be fun.... but be careful about over-running the pavement into the grass...