yardsparrow

Junior Member
Hi FT community,

For my third build I've chosen the FT Versa Wing speed build kit. My question is on Servo placement. In the build video it looks like Josh places the servo's so the arms are facing back toward the elevons. Maybe I'm not centering my servos properly but when I do this, the servo arm movement does'nt seem symmetrical. Both servos are centered in the top wing cutouts but the left side arm wants to hit the foamboard at the front of the cutout. The right side wants to hit behind the cutout. Is this normal behavior that can be mitigated when I program the Elevon Mixing and DR throws? or am I doing something wrong?
I haven't glued the wings shut yet until I get this figured out.

Thanks
 

Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
Good to check before it's all glued in.

So from what I'm reading, the servo head (the plastic moving bit the horn sockets into) is centered on the hole, the servo is electrically centered and the horn is mounted as close to 90 degrees from the servo/wing skin as you can get . . . and one hits the front, and the other hits the back of the hole.

First off, this is NOT a huge deal -- at worst you might have limited throw on your surfaces, but the versa has PLENTY of throw.

It does sound like the horns aren't exactly centered on the servo head. The teeth in the spline between the horn and the head can throw you off a few degrees, so no surprise, but it sounds like one is offset forward and the other is offset back. if you want to move the left horn back a tooth on the spline it might clear this up.

When it comes time to setup your radio, so long as they respond more or less the same, you'll mechanically trim and subtrim so they're aligned with a little reflex (upward elevator) and then limit your servo throws so it doesn't bind on the ends (or cut a little more foam so it can travel the extra few degrees).
 

yardsparrow

Junior Member
Thanks ! you are correct, the servos were off center and the heads faced forward not back. I replaced them as shown. I think next I'll glue in the control tabs and temporarily hook up the control rods and electronics. Then I can program the elevon mixing, throws, expo and trim to see how things look before gluing it all shut.

IMG_20150326_212829.jpg
 
you may find that you need to extend the slots to get the throws.

I had to on mine, just to prevent my linkages binding on the surface.

Edit -
I found my servo control links to be badly worn, this lead to a very twitchy plane.
to combat this, i turned my servos 90 degrees, so the tops were poking out of the top of the wing. The tabs that are on the side of the servos, were just the right height, to wedge under the top skin.

I now have a super smooth flyer, that is a pleasure to fly. (now upto flight 50 ish)
 
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yardsparrow

Junior Member
versa-pre-glue.jpg

Programming in the Elevon Mix with my DX6i brought the servo swing down quite a bit. Everything looks free and correct now at 100% throws. I think it's time to glue it up !
 
may i recommend, some down wash on the motor. mine has an ice lolly stick as a packing piece under the top mounts for the motor, and it still climbs under power.

i have it trimmed for 1/3rd throttle, and she really flies so nicley at that speed, but if i go any higher, she starts to climb, (this is not an issue for me, as i quite like it, it really helps getting altitude early, then i chop back to 1/3 throttle, and just pootle in the sky :p )

but, it is just something i think you should be aware of for your maiden :)

good luck, anf fair weathers for you,



Tony.