mtomas

Howdy - I am trying to increase the control throws on my 4*40 but have run into a bit of a road block (see pic below). When the servo travels in the direction of the arrow, the control horn reaches a point where it will pretty much come in line with the torque rod - there by limiting the movement of the servo (and the aileron) in that direction. Unfortunately, the point of limitation does not give me satisfactory aileron travel. Does anyone have any ideas of how to get around this? (hopefully without major reconstruction).

Scar

My Feedback: (3)

The drawing shows the torque rod end not perpendicular to the aileron. You could bend the torque rod, and lengthen the servo link.

What makes you say the travel shown is not adequate? Have you flown the plane and found it inadequate? One doesn't usually need a lot of aileron travel on a 4-star.

Good luck,
Dave Olson

mtomas

The drawing is not intended to be to scale (my artistic skills are lacking )

Your right though, the torque rod is not perpendicular to the aileron. The torque rods come bent from the factory to help with aileron differential.

The actual problem comes from the fact that the 4*40 uses a single aileron servo setup. I tried to be brief in my original question, so i left some stuff out to make it shorter.

The down travel is my actual problem. I cannot get the throw to exceed 1/2" down (which is the factory recommended position). When one aileron travels upward, the opposite aileron travels downward. the down travel gets blocked by the limited distance the opposite up aileron can travel. I have the pushrod connector thing on the torque rod screwed out as much as possible (which I know does not help with the down travel, but if I move the connector down the torque rod, the point of "servo blockage" happens earlier in the up travel and limits the down travel even more.

I hope this made sense.


I am trying to wring the plane out as much as I can in preparation for moving on to a hotter plane. I have flown it for quite some time with the stock configuration (ailerons 5/8" up and 1/2" down) and love it. I figured increasing the control throws beyond the basic configuration would be a good placed to start!

bingo field

Use outer holes in the servo arm, this will give A: more throw B: more clearance. If you are using the outer holes, look in the kit that came with your servos, you probably have some with slightly longer arms. With more throw, just a caution, you will get more and faster aileron deflection. "Make changes slowly, only 1 change at a time." This eliminates confusion as to what change may have caused which problem. (KISS principle, keep it simple .........)

Chris Moon

My Feedback: (8)

You can also make the ailerons more effective if you have the hinge gap sealed. The ailerons will be more effective without any additional throw if you are maxed out on the amount of throw you can mechanically add.

Geistware

My Feedback: (16)

Move your contrrol contact point closer to the surface of the control.
You should be able to get more travel.

Mike in DC

I think Scar has it right. Bend the torque rod. You can live without the differential, and actually, I don't believe the factory intended the rod to be bent so much you can't get enough throw.

Stick Jammer

The chord of the 4*40 aileron is pretty small so there is only so much effect they are going to have no matter what. Moving the control horn contact point closer to the surface of the aileron isn't likely to help if the throw limit problem is mechanical in nature due to the pushrod becoming in-line with the control horn. Larger ailerons have much more of an effect on flight as you will likely see when you move up to your next plane.

Dano13

How about a ball link on the end that is binding? Or do I mis-understand the problem?

Dano13

nicadflyer

Use a longer servo arm (outside hole) and move the torque rod connector closer to the aileron. This will give you more aileron movement. Adjust as needed.

Paul

Scar

My Feedback: (3)

Ah! I want to commend you for starting with the 4-star and using it as your "mule" in preparation for a hot plane! Actually, the 4-star is great, for that purpose.

However... if you're at that stage, and wanting more aileron authority... you're probably ready for that next plane. The 4-star is great, but she's a bit more stable than most of the really aerobatic planes.

What's your next one? Sukhoi? Extra? Cap? After my 4-Star, I flew a Kaos (briefly; learned not to pull up elevator when inverted...) and then a Global Tequila Sunrise 40 (Man! Did THAT teach me not to pull too much elevator! Still have it, never wrecked, now I realize it's underpowered with a .46 and it sits on the shelf most of the time.) I also had a Lanier TR260 plastic ARF (delightful plane, 78 great flights, good aerobatic trainer, spun in without explanation one day) and my favorite aerobatic trainer, a Vmar Extra 300 (flame suit on!) That one is bulletproof, agile, inexpensive, and I cared not one whit whether it augured in or lived. Now with 300+ flights on it, it hangs in the garage near the Tequila Sunrise most of the time.

Anyway, enjoy!
Dave Olson