Advice on clevis for EDF?

[herk1]

My current build is a faster, heavier, plane than I've built before -- Windrider F-35 with HET fan on 4S -- so I want a beefier pushrod-clevis linkage than my usual parkflyer system, which is to use .032 to .047 music wire with a z-bend on one end and a Dubro mini-EZ connector on the other end. What would be a good next-step-up clevis/pushrod system, that also has adjustability? When I start looking thru Horizon or Tower for clevises, there's a lot of different stuff out there, and it's not clear in many cases exactly what rod part I need to buy for a particular clevis, or how it's supposed to attach to the servo on the other end of the rod from the clevis, and I don't want to end up overdoing it with some big heavy part designed for large-scale gassers (kind of hard to tell from looking at the photos whether it's going to be a big clunky part).

I'm building the plane with full-flying tailerons and no ailerons. I already installed the tailerons with the metal hinges that come with the kit. And I enlarged the servo pockets to fit some HS-82 metal-gear servos that I got for it. What comes with the kit are just plain pushrods with a z-bend at each end (so no adjustability) and are made of a very soft/flexible metal...I won't be using those!

[ATIS]

Mark,

I use Z bends on one end and the quick connects on the other... I just increase the diameter of my piano wire and use loctite on the screw that pinchs the push rod on the quick connect. I have never had one come a part. The key is make sure that the quick connects hole is the exact same size as the pushrod so that there is no play in them. Once you get everything connected and leveled you can always mark the pushrod on both sides of the quick connect and then remove the pushrod and add a flat spot on it between the marks for the screw to grab.

The biggest issues you need to worry about when setting up a plane that goes faster are:

1) Solid control clevis attached to the surfaces... I use the two pieces ones and add epoxy on both sides...and then paint over them.

2) Thick push rod to avoid flexing

3) A servo with more tq then you need...because they are rated for tq strength normally 1/4" from the servo mounting hub so as you move farthur out on the servo arm to gain more throw your going to lose tq. Also as you move the pushrod closer to the control surface on the clevis your going to loose the mechanical advantage as well.


You could use the pushrods that are threaded and use the plastic or metal clips to connect on one end (the exposed end) as they are adjustable and then a Z bend on the other (at the servo).

[rcdude07]

On the planes my dad and I build, (.40-.60 glow fuel balsa planes) we always use the control horns that are two pieces and screw together.

We also pin the hinges. After the hinges are in place, using a small drill bit, drill a hole just big enough for a toothpick, push the toothpick all the way through and glue in with CA. Clip the ends of the toothpick, then sand smooth.

I'd recommend using clevises on both the control horn and servo, just because it's more secure.

Wherever you have a clevis connected to a control horn, take a piece of fuel tubing and slide it over the clevis once connected to the control horn. This will prevent the clevis from accidentally popping off the control horn.