So I bought one from RC Machine, took three forevers and a day to arrive, finally fired up T-Rex #2 (my future scale build bird) and the Gyro was acting totally weird. Long story, but I went thru all the normal setup and tuning steps with a GY401, copied my 'program' in my Tx from T-Rex #1, adjusted up and down the AVC settings (gain) for HH mode, Reverse switch, etc and still the helo was spinning in place.

So I thought I'd tried my other Futaba Rx, a 148dp (also a PCM1024 Rx on the same channel) and the Gyro was acting differently. I couldn't get the bird airborne as I apparently need to do some more overall tuning BUT the 401 wasn't letting the bird Piro' on the ground like the 146ip. Any ideas? I'm highly confused at this stage and I will post this on the Tx and Rx section of the RC Groups too BUT I thought I'd start with the Helo' experts first to get your input.

Thanks and Happy Flying!

I've been using the 146ip without issue for over a year, it's a great little TX. Just a guess.. but, are you sure the gain lead on the gyro is plugged in correctly?

I think I figured it out, I'm running an Align 35X ESC which is running a 6 volts and I think the 146ip is NOT happy with this much power. I swapped over my 148dp Rx from T-Rex #1 and the Gyro seemed to be fine on Rex #2; the bird is setup badly but it wasn't acting the same. So I'm going to try an Align 5.1 v drop down regulator on the 146ip and see if that solves the problem. Man if it's not ONE thing it's another, I thought I was finally going to be flying that bugger today, arrghhh! Welcome to the wonderful world of RC stuffs eh?

Happy Flying!

Update: Got the Align 5.1 Volt Drop Down Regulator, plugged it into the 35X ESC's 'input' into the Rx (so the whole bird is now at the lower voltage), got the 146ip all secured and setup and she flew with no problems whatsoever. I now need to get T-Rex #2 up in the air to confirm that I'm not having Gryo problems so I'll be using the 148dp Rx at 6 volts throughout the helo and we'll see here shortly.

But the major question I had was answered, the Futaba 146ip should be run ONLY at the lower voltages, at 6 volts you're going to run into all kinds of problems so keep that in mind and just get a 35G ESC (or equivalent) and same yourselves the headaches!

Happy Flying!

Originally Posted by Drew816

Update: Got the Align 5.1 Volt Drop Down Regulator, plugged it into the 35X ESC's 'input' into the Rx (so the whole bird is now at the lower voltage), got the 146ip all secured and setup and she flew with no problems whatsoever. I now need to get T-Rex #2 up in the air to confirm that I'm not having Gryo problems so I'll be using the 148dp Rx at 6 volts throughout the helo and we'll see here shortly.

But the major question I had was answered, the Futaba 146ip should be run ONLY at the lower voltages, at 6 volts you're going to run into all kinds of problems so keep that in mind and just get a 35G ESC (or equivalent) and same yourselves the headaches!

Happy Flying!

Great info. I am using 146ip in my TRex for a while w/o a problem. But I am using CC 35 ESC that outputs 5V and now I know I was lucky.
Thanks for reminding me Align 35X outputs 6V that I forgot too.

Ok, things are still screwy and I can't figure out WHAT the heck is causing my problems. I think I'll start another thread becuase I'm not suspecting the Scorpion -8 v1.5 as the prime suspect here, but basically no matter what combination of parts I move over to T-Rex #2 that has the Scorpion both of my GY401 Gyros can not keep the tail from wandering; badly I might add (like 90 degrees in the direction of main blade rotation within 4-6 seconds).

I've stated by moving my 148dp Rx over from T-Rex #1 to this helo #2, same results, tail wandering.

I then flew the 146ip in T-Rex #1 w/ the Align 5.1 volt drop down coming off the ESC to the Rx and it flew perfectly. I flew this 4 times back to back with my Dad in town visiting and 2 times back to back earlier in the day with no problems, the 146ip w/ the drop down seems to be fine in T-Rex #1.

I switched my 401's back and forth and on #1 they work perfectly, on #2, wander.

My latest 'theory' was maybe the tail slider assembly was binding so I took the extreme action and moved the entire very functional tailboom assembly from #1 and moved it to #2, it flew once 'ok' with a little bit of wandering, I then went to a second battery and it was wandering instantly! What the heck is going on here?!? So I installed the entire tail boom assembly from #2 onto #1 and just flew it and it flies fine, so it's NOT the tail boom-rotor assembly.

Here's the layout of the setup on #2, the 146ip (w/ 5.1 drop down) is located underneath the battery tray so the Scorpion is sitting pretty close, maybe it's messing with the Rx?? The ESC us towards the back of the lower tray getting some cooling from the gearing, the gyro is under the tailblock boom via one of Rick's "thingie" mounts.

I've spent more time chasing this gremlin then I spent building BOTH T-Rex's up from nearly scratch (as you can see from my list of testing steps above). If I had an extra motor I'd just pull the -8 and try another but my other motor met it's maker a week or so ago.

Thoughts?

Drew,

I don't think its your receiver. I have this (146ip) in two V2s (RCE-BL35X (35A) @ 6V, 401 + 9650, 3X hs65mgs, no issues, in fact its perfect -- I have yet to get my first glitch. I am using a 7chp. Before I bought that receiver, I checked it out extensively and its probably the best receiver for a trex set up. It's been flawless.

Bird 1

frame

bird 2

frame bird 2

Bird 1 has the esc up front under the batt tray, while bird 2 it is strapped to the right side of the frame up front (I like that better). It doesn't sound like its an interferance probelm, but just the same I have the wire to the receiver outside the frame, right side, away from anything else + ferrite ring. Receivers are both sitting at the end of the lower flatform, one flat one on its side, pushed back and velcroed so they are just barely handinging out the back. I'm using antenna tubes, no overlaps, coils, not touching anything, or based loaded, with the end of the antenna terminating via a loop w fuel tubing off the horiz stabilizer.

If I were you I would verify other things, such as making sure your signal wire is indeed fully seated in the receiver, also go thru all your settings, make sure your gyro is going to HH. I was futzing with one of them when I was doing an LED lighting project and managed to knock the signal wire somewhat loose and it wandered and would not go HH until that was fixed. I was using a diff plug, not the 401 plug and that caused the issue.

Maybe step through the entire finless set up vid and see what happens..but I think you have a gyro set up or hook up issue at this stage, not a receiver prob. Also, I dont think its a great idea to copy settings between birds, I would just set it up frome scratch, in case there is anything different between them. Lastly, make sure the grub screw that holds the tail hub to the tail shaft is indeed loctited and tight so there is no slipping. Ask me how I know..

Maybe bad tail-drive gear?

Hi Santini.
I ahve exatly the same birds with you (!).
I use Park Bec at 6V and 5V for the 9650.
Is it safe with this receiver?
Me too had never any problem, but I am wondering about Rx and 6 V. I never read anything about that.
Is there any refference or just rumors/
Best
Takis Katsoris

If you have the same set up, then you are good to go. I dont use a bec. I've never had a glitch...

Just flew T-Rex #2 with the Align 430L motor and it flew fine, no tail wandering, no twitch, no issues. Now that was just one short test flight; the weather is crappy here at the moment and likely to get worse; BUT before the tail wandering would start instantly. So #2 has the 146ip w/ the 5.1 v drop down under the battery tray, 35X ESC in the body under the gear (for some cooling), Gyro under the boom mount.

I also flew T-Rex #1 now equipped with the Scorpion -8 motor and it flew fine, no issues besides the fact the 35X ESC is really under spec'd for this motor (so I'm playing nice) but NO wandering.

I started a thread over here as well specifically oriented towards the Scorpion motor being my 'prime suspect' and I'll post the above results there as well.

http://www.rcgroups.com/forums/showthread.php?t=855138

Very curious, I don't know what to make of all this BUT I'm going to not mess with success and leave the Rex's setup the way they are and keep flying them to see if any 'issues' return. If not, all the better, but I'm at a loss as to what the problem was to begin with. I think the Scorpion was interfering with the Rx but that's totally a guess, but mechanics seemed to have been eliminated as the possibility; that is ASSUMING that these problems don't return on my next flight of course!

UPDATE, a few hours later in the day:

Ok, two more flights on T-Rex #2 and no issues, one more flight on #1; I'm at a loss as to what the issue really was but so far so good. So the motor switch obviously did something 'positive' here and must have been at least a contributor; BUT keep in mind the Scorpion was right next to the Rx and is pumping out some serious power and it's working fine in a more average setup so just something to keep in mind when building...