Q: When you install the servos on the hatch cover as per plan, how do you adjust the servo arm set screw or linkage at the field without taking the whole thing apart? I'm more inclined to attach them the underside of the hatch cover rail ( plus one more ) so that just the gear comes up through the plate opening? Bad Idea? ps: I hate soldering anything if that means anything. Mikel-T

Mikel-t,
Adjust the throws at home. All I've ever needed to do was adjust the clevis at the aileron at the field. I've never had to take servo arm off.

If you did need to adjust the arm - you would have to take it apart.

Enjoy the 4 Star. I really liked mine.
John

I built mine per plans. The servo arm should be centered b4 you head to the field. This then should not need to change. I used a standard pushrod with a Z-bend at the servo end, and a clevis on the aileron end. You can then easily adjust the ailerons by moving the clevis in or out.

That's right. Once the servo horn is installed at the 90 degree neutral position, it should never be moved. If adjustment is necessary, do it with the clevis.

I don't like to solder either, but I usually solder the clevis once it is trimmed. Otherwise they will eventually loosen.

Tom

Allrighty then... I'm back in the game, thanks guys it helps to hear from those that have been there and dun that!. Mikel-t

I like to set mine up so that the arm points a bit towards the front of the plane so I get some differential - more throw up than down.

But, sure, do that at home and leave enough room on the clevis end to make adjustments.

You are using the APG per instructions to set the center, aren't you?

If you're soldering, and you use a plastic clevis at the aileron end, remove the plastic clevis first or the heat travellling down the metal rod may damage it.

When you solder, leave the plastic clevis on-- it'll destroy it and make it easier to remove when you replace it with a proper metal clevis...

I use wire with 4-40 threads at one end. Solder a clevis to the rod at the servo end and use a clevis at the threaded end for initial adjustment. With a locknut.

--Bill

Exactly!

Guys, I have used Dubro plastic clevices (black nylon with metal pin and locking clip) with no problems on 60 and 90 sized planes. Pattern fliers also use nylon bodied ones from MK and Tettra with ball bearings on their 140-160 sized planes. They are lighter than metal clevices. Not being biased towards plastics but it is a modern day engineering material............

Rajul:

You are both right and wrong.

There are indeed some high quality plastic fittings available, my favorite links for anything larger than a 40 plane have brass balls, but the body is plastic.

And how many all metal control horns are there? Even the fancy metal "Bolt-throughs" have plastic parts.

However, the majority of the links supplied with the 40 size planes are complimented by calling them a POS. And the control horns are similar quality.

When you ruin them you are doing yourself, and the world, a big favor.

Bill.

I'm learning a lot here. I very naively used all the plastic stuff when I started a few years back. I've had some break but only during installation or in a crash. I've probably made 1000's of flights without a failure.

The plastic ones seem to have less slop since you can press them tightly into the hole.

BTW, I've have had trouble with the metal ones getting loose at the threads. Funny how we have such different opinions about the same things.

Tom

Tom:

Some additional words about metal clevises. My preference in metal is the Sullivan clevis, with the metal locking clip.

But since the threads have clearance, allowing you to assemble them to the push rod, assuming the threaded ones, of course, that clearance will allow the two parts to vibrate, one to the other.

At best this will cause wear and increased looseness, eventually failing. At worst it can cause RFI and radio failure before it comes apart from wear. Either can cause destruction of the plane.

So if they are so bad, why are they so popular? Simple. People have learned how to prevent/eliminate the looseness.

1) Strong LockTite, the red, not the blue.
2) Run CA into the threads after adjustment.
3) Use a locking nut as BillHarris said. Sullivan also supplies very small brass locknuts in 2-56 thread, I think they also have them in 4-40.

My method, akin to belt and suspenders, is the lock nut AND CA. Never had one come loose. Or wear the threads.

Bill.

I use the Sullivan clevices myself, but have started using the new DuBro heavy duty plastic clevices with a metal pin and a captured metal clip. There's no metal-to-metal and they lock. They're also hard to open when they are unlocked.