View Full Version : Big doings on the TREX Heli front !!!

Pony Pirate
03-19-2007, 03:49 AM
Big doings on the Trex Heli front....the servos are in the machine and all wiggling in the proper directions at the proper time !!!!!! YAY !!!

03-19-2007, 01:50 PM
Next comes the fun part... Getting all those servos to wiggle properly in flight...

Pony Pirate
03-23-2007, 10:12 PM
Here we go again....:o
I appear to have painted myself into a corner...I just tried to put the tie wrap into the frame for the servo wires and lo and behold I can't seem to do it.....any experience / thoughts?? It appears that I have to remove a servo to run the tie wrap...so I removed the servo and ran the wire tie wrap,,,*sigh*
Did I miss something ?? This kind of plan related stuff is getting old...
I saw finless bob's electronics video showed heat shrink and other coverings for servo wires used by some people..has anyone problems with shorting or severing of these wires going through the cf frames sides ?? the coverings look neat and trim but are they a necessity??...
Well I have the tail feathers mostly attached...I'm using a Futaba 9650 digital servo for the rudder....When I received it from DT it only had the "wheel" output arm...shouldn't there be more than one style output arm ?? unless i'm having a senior moment does this one mount upside down unlike the plans show (diff servo). Isn't the current thinking to mount the gyro on the bottom to save boom strike troubles ??
Thanks in advance....

03-24-2007, 03:31 PM
Both of my 9650's came only with the round servo wheel so I think that is normal. I had a tail wag develop when I tried 335 length blades and I had to drill a new hole as close to the center of the wheel as possible. Another common modification is to get rid of the "Z" bend at the servo end and install a ball joint.

The gyro has to be mounted on the bottom so the pushrod from the tail can have a nice straight run. My 9650 is hanging from the bottom of the boom with it's butt tilted about 30 degrees up. I loosley mounted it and connected the control rod and moved the servo until I could get the pushrod to line up with the guide.

I did not use any heat shrink or spiral wrap on my wires. Getting wire ties threaded through the frame can be a pain. Sometimes I will pre-bend the tip of the wire wrap to help it make a tight 180. I use hemostats and a small pair of needle nose pliers to reach inside the frame to guide the ties where I want them.

Pony Pirate
03-24-2007, 06:35 PM
Thanks for sharing your experience and knowhow, I really appreciate it !!
I'm seeing something strange with the pushrod to the tail...the mount that holds the horizontal stab causes the pushrod wire to be bent slightly closer to the tube when I put it into the bottom notch..) not awful but not straight either,,,(these are all factory parts so go figure ??)
I'm relying on finless Bob's videos however some of my parts are different but the principles are still good...just relying on the plans would be really hard to do...ok on the hemostats ...they bring me back to ucontrol fixed wing models.
I was afraid that the cf sides might cut the wires and short them out...but my fear appears to be unfounded...
now I will have to set the head up..this appears to be a bit on the tough side to do but I'll muddle through...

thanks again...

Pony Pirate
03-24-2007, 06:41 PM
I meant to add that my 9650 mount has 4 alum fittings that appear to cause a solid mount with no rubber cushioning...yours too ??


03-25-2007, 01:34 AM
I have an SA and the brackets that clamp around the tail boom are plastic (no fancy machined aluminum for me).

I cut the side mounting tabs off my 9650 so I could have easier access to the top mounting tabs. I have rubber grommets with brass inserts to attach the servo to the mounting brackets so the screw tightens up against the brass insert and the servo floats on the rubber grommet.

My center support for the tail pushrod also pulls the pushrod out of alignment. I have flown with it clipped in and out and have not noticed any difference. My pushrod guide was very tight out of the box. I drilled out the guide so the pushrod could slide without any resistance.

My SA frame has aluminum side plates and the edges are a bit sharp. I just attached the wires so they cannot vibrate and cut through the insulation. If you have a really sharp corner you may want to file down the sharp edge or put something between the wire and sharp spot. The one spot I have heard some people have trouble with are the wires connecting the battery to the ESC since they are loose and can move during flight and they get pull on a lot when disconnecting the battery.