chemie

A few questions after inspecting the included hardware with the Sig 4*-40 ARF:

1. Throttle control is with a 3.2mm nylon rod. Is this OK or should it be replaced with rod or wire? Note I will use [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXD929]Dubro[/link] E/Z connector on the servo end.

2. I am replacing the clevis supplied with [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXWH36]Dubro[/link] Safety Lock Kwik links at the control horn end. My question is should I use the supplied clevis on the servo end or something else? See photo for what is supplied.

The rudder and elevator have 3.2mm nylon control rods...I will give these a try before replacing.

Finally, does anyone have a photo or measurements for the aileron servo tray? It is supposed to have a doubler on one end but this one did not come with one. I have some 1/8" ply I can cut but I am not sure how much should be doubled.

Thanks.

Campgems

The cost of some sullivan or dubro metal clevises will give you a lot of piece of mind. I don't like the plastic ones. The down side to the metal ones though are that the rods usually supplied are not #2 or #4, but metric sizes. You may need to replace them also.

On the throttle, I am a big fan of the cable linkage. The flexable nylon is second choice. Steel rod or wire only works well if you have a straight shot from the servo to the throttle. Otherwise you get binding and/or a lot of bends that have to be made after the rod is installed. With the cable, you can easilly route it around the fuel tank and to the engine without any binding.

Don

PS, Does the 4*40 use a single servo with torque rods or dual in the wing servos. I've only built the 4*60's.

chemie

The metal rod in the photo is 2mm threaded rod so I need to adapt to that. The 2mm rod threads into the 3.2mm nylon control rod.

Yes, the aileron is a single servo in the middle of the wing with torque rods.

seahwk95

My Feedback: (1)

Just a quick note. When I recently assembled a 4 * arf, I attempted to use the ez connectors on the servo end (rudder and elevator) and the height off of the servo with the connector kept the wing from seeding properly because it kept hitting the torque rods (Don, the 40 arf stock is single servo with torque rods). I ended up using clevises on the servo end as well. Also, I replaced the stock nylon rods for the rudder and elevator with sullivan golden rods based on some stuff I read here regarding the plane getting out of trim with drastic temp changes. I have noticed that I've had to trim mine out on several occasions even with the golden rods, so if I had to do it again I might go a different route. I did use the stock nylon rod for the throttle and haven't had any issue with it.

Campgems

My current plane has short all steel rods and I have to do some drastic trimming now and then myself. I've built and killed two 4*60s, one with golden rods and one with the stock rods that came with the kit. Triming was almost unheard of with those two. So, I'm not sure that there is a silver bullet for trim free operation.

I would be tempted to build the aileron servos (plural) into the wings like the 4*60 has. If you have a TX with mix capabilities, it gives you a much better trim setup on the ailerons. In fact, I have a first generation Quicke 500 that I took the single servo out of the wing and put two mini servos in it place. It worked well until I discovered the hard way one day that with the throttle cut, the left aileron was hitting the throttle linkage and I had no down aileron on the left side at full idle. I dead sticked and cut the throttle to keep any junk out of the engine if I crashed. I found I couldn't make the final turn to the runway and watched it float over the hill and out of site. Minor damage. I'm going to build the servos in the wing on the rebuild now.

Don

chemie

Seahawk: I am surprised there is that little clearance between servos and the torque rods!!!! (No way to tell since you can not see in there when it is buttoned up.)

seahwk95

My Feedback: (1)

Hi Chemie,
Trust me, I WAS surprised and it took a little while to figure it out but once I removed the ez connectors the wing fit right in. It may be worth a try however. I might have been using heavy duty which are a little larger. Good luck.