Posted: 2/17/2026 10:25:55 PM EDT
[Last Edit: Bollocks44][Edited]
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title edit From this Attached File To this Attached File ETA: This is a long read but could be helpful for anyone here looking to get into RC Helicopters. To also let you know what you're in for as these fuckin things aren't easy or simple. TLDR: Setup a new Heli but its been a long time and forgot/did some shit wrong and frustrated the shit outta me trying to figure out what was wrong then a Pro Heli guy helped me figure out what was most likely the cause and hopefully its all good now. So I recently built up a new Heli. Steam AK420 HDX. As far as Helis go, its on the cheap end but supposedly flies awesome and parts are cheap. So I take her up first time and she has a gnarly tailwag. After some investigation and digging around on the FB groups, I moved in the ball link on the tail servo 2mm in to center, lengthened the tail control rod to about 385mm and honed out the tail control arm links to allow for smoother action along the tail spindle shaft. That seemed to 95% fix it, the remainder being tuning the gain rate in the Transmitter. Next issue was she was draining a whole 6s pack within 3 min on a light hover which is not normal and later find out my Idleups aren't engaging.... well its been a good while since I've done a new full setup and when I switched over the ESC from an older Heli, I didn't calibrate it correctly. It was still setup for completely different headspeed and usually you have to first run in ElfGov mode then switch to StorGov mode to calibrate the correct headspeed for the Heli. I just updated the firmware which reset it anyways and was able to get the correct numbers I needed to set my Throttle curves in my Radio, and my Idleups were working correctly now. So I take her up again thinking everything's cool and do a quick hover and notice she does a quick jerk up everytime I bring her down to land. Batteries aren't getting zapped like before so thats a good sign. So put in another pack, take her up for another quick hover and bring her down, hit Throttle cut and she immediately spools back up and takes off about 4 feet, does a flip and lands on her head. So yeah thats not supposed to happen and freaks me out and I'm like what the fuck??? Luckily the damage wasn't too bad, I just had to replace the feathering shaft and did the main as well just to be safe. But my servos were all locked up with no input from the sticks. Go back on the FB groups and people are suggesting its the FBL thats malfunctioning. Cool, switch out the FBL with another one which is same unit, and boom, I get all servo control back and everything seems to be working fine. Soo I take her up again this time feeling confident problem solved and I send her on a legit flight, circuits, flips, rolls, flying inverted for a bit. She seemed locked in and finally flying well right. So bring her down and change to another pack, spool her back up and as soon as I go positive on collective, she blasts off the ground like a fuckin rocket and legit is flipping her lid way the hell up in the air. Like doing Piroflips and spinning without any input from me. I have zero control of the Heli. Only thing I could do was hit Throttle cut and she falls like a stone to the ground. So now I'm like this fuckin Heli is straight up cursed. Also not safe at all which goes without saying. So now Im at a loss as to what the hell is happening and how can 2 FBLs go bad just like that? Only thing ai could think of was that I updated both recently to latest firmware and maybe that screwed something up? Well once again I get on the groups and post whats goin on and of course get all kinds of different theories about what could be causing this problem. Then one of the Pro Heli guys who lives in Canada and has a grip of knowledge hits me up and walks me through some diagnostic tests and we troubleshoot for a while and turns out the main issue is I didn't have my Failsafe setup in the FBL. Fuckin A what a dumbass overlook on my part but like I said its been a good amount of time since Ive done a setup from scratch and it just escaped my mind. We also traced the issue to possible bad wiring and or bad receiver so when I lose signal in the receiver and there's no Failsafe setup correctly, then essentially the FBL is stuck in the last input it receives and wont work like it should which results in an out of control Heli. Now I know why a lot of guys run Auxiliary receivers on their Helis. I was also running the ESC power wire to the Rx then a separate wire from Rx to FBL which is not the best way to do it come to find out. So yeah now Im waiting on a grip of parts to put her back together and going to put in a new Rx and already setup Failsafe so hopefully 6th times the charm ?? ?? |
One thing I always loved about helis was the precision side of setup. Nothing better than spending a bunch of time on the bench to have it fly perfectly on first outing. Granted, I flew with actual spinning gyros.  I learned on a Lite Machines LMH-100. My first "real" heli was a Century Hawk. On the first flight it came up to a hover, perfectly, not a wobble. It started to yaw a bit and I added correction. Which did nothing and it just started yawing faster. I realized something was wrong. So I hit throttle hold and made a perfect landing, with just a wee bit of bounce. The second bounce landed in a gopher hole, heli tilts, blades hit, then takes out the boom, etc. I had missed a bit of CA on one of the pushrods guides, which jammed the pushrod. Lesson learned. 
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