Hi, I'm just putting togther my first plane equipped with retracts. With the retract servo in the neutral position is it best to have the landing gear up or down?

Thanks

Shane

It doesn't matter because a retract servo is a 180° servo. It only travels from one point to another, so there is actually no neutral point on the servo. It's either going to be at one end of it's travel or the other.

Ken

The servo for mechanical retracts works differently than other servos. It has two positions, up and down. It has no neutral. There are reasons they are like they are.

When one of them is either up or down, they do not draw current. And the rigging has them at full throw, so there is little or no leverage against the servo arms. They rotate 180degrees or thereabouts going from full up to full down. THEN they draw current.

Mechanical retracts are designed to complement those servos. The retract actually doesn't start moving the strut until the actuator arm has moved something like 15% of the total movement. The actuator arm is actually moved into a mechanical locking position when full up or fully down. The actuator arm does not have to hold the strut either up or down. The last 15% of movement moves into lock at either end of the throw. It all works like gangbusters.

Here is a picture of the retract servo in a Kyosho P40 Warhawk. It's a 46size warbird.

(Ken, darned if this isn't yet another time we were both typing away at the same time.)

anyway.....................
here is a picture of those retracts down.

What plane are you putting them on?

Good Luck!

Measure the throw of the retract mechanisim. Lets say for an example the pushrod moves 1" from full up to full down and locked.

Get a servo wheel and space the two connections to that wheel 180 degrees apart and the same distance that you got from measuring, in our case, 1" apart and equidistant from center. If you have to use a blank servo wheel and drill a hole do that, dont use the holes on a stock arm that are "close enough"

That will give you perfect retract throw. MinnFlyer has a great diagram somewhere.

This one??

Ken

Guys thanks for all the help. They are going in a Seagull Texan. I'll have a go at putting it together later today.

Do one side at a time and get it working and set right up and down before doing the other side. I have several planes with mechanicals. They work great when set up right. Those photos looks good too. Thes servos are not proportional. Cannot adjust the travel at all, strictly 180 degrees off.

Also take into consideration the rods you use. In the last few years I use 4-40 now because thinner rods can bow out. More stable this way.

Hey, Ken, fair out okay?

Fair out???

Ken

He's probably is talking about all the rain and flooding that has hit Oklahoma. My guess is yes since we didn't see you hanging off the skids of a helicopter falling into the water a couple of times on CNN. Then again based on the sticker on the nose of your Hog Bipe.............. [X(]

Hogflyer

hogflyer you gotta tell me where you got that sticker. that is awsome.

Dirtmagnet,
That's on my Hog Bipe!!!!

Ken

Well I've finally had time to get them installed and seem to have the servo set up correctly as they lock at both ends of travel however there is a lot of freeplay in them. When extended they move around 10mm side to side. Is this normal or is there a way of adjusting that out? I don't know what brand the retracts are as they came with the kit.

Thanks

Shane

Hmmmmm What brand retracts? In a Seagull ARF.....

I wound up with 3 different "brands" of 40 size retracts for the Warhawk. Trying to find some that were worth using and worked on a dihedral wing and turned the right directions. Turned out all of them had the same "reinforced nylon" (some kind of hardish, dark plastic) bodies and innards. All had some play and no adjustments. They all measured the same but came from different "mfgs".

Sounds like the ones I have. They have plastic innards with a blue metal casing. I'm just concerned that with that much play it's going to be very unstable on the gorund.

Actually, I've not found the play to cause any ground handling problems. It just beats up the innards quicker. And sometimes rattles in flight. When one of mine got real bad, I ordered another set, wanting to stay with the same brand. The "same brand" that showed up was branded as World Models (if the WM on it means that). And had no play in either side, so I swapped both out. I immediately ordered some from WM and got ones that looked the same and didn't have WM on them. And were a bit sloppy.

Not a one I've gotten has a blue metal casing.

Ken I got to get some of them Calvin Heli decals. You make them? If so ,I`ll take a dozen.

You want the ones with the helis on them???

Ken

Yeah, Just like on your nose cowl. I fly with a lot of Heli guys, most times I`m the only wing guy there out of 6 or 7 . Thier a great bunch , and would get a kick out of it. Got any for electric also ? lol

http://www.callie-graphics.com/

I can just about anything ya need!!!

Ken

Thanks. I'll give them a go and if they're no good I'll get another set.

Well I managed to fix the freeplay. There was no adjustment in it so I put some epoxy on the flats which lock the gear in position and it works like a charm... on the bench at least. It will be interesting to see how long it lasts.

If you have too much free play and your already on the outside hole on the servo arm, may want to get a larger arm. (This of course without seeing the setup but just a guess.