130x with lynx rotary tail servo

[Bhujang]

Hi

I know this is history now and many have moved on to the 180cfx as I also have but I still love my 130x's

Can anyone point me to a thread that helps with setting up the tail servo with a rotary one such as the lynx. I've been out of the loop for ages and back in now but my rotary tail servo just isn't tuned in enough. I'm not sure if it's the throw being out or the wrong pitch on the tail blades that need setting with the motor unplugged and gyro on.

I need some pictures of the tail blades to see the angles I'm looking for to stop the tail flipping the heli around when I'm heavy on the collective and then swinging back when I stop.

If there's an existing thread with the way to set one up from beginning to end I'd really appreciate a link or if some die hard is willing to help me out with some text and pictures or a step by step set up,I'd really appreciate it as I'm not sure what I'm doing wrong. The lynx tail servo,is working fine no jitters but it just won't hold. I'm using the extreme spin motor on one and the lynx on another but both have tail issues and I'm sure it's the set up.

Thank you gurus much appreciated for any help you can offer.

Cheers

Bhu

[vtown nick]

What I always do is with a 0-100 curve just lightly raise the collective with throttle hold off holding left rudder watch for when the servo goes full travel. It's around 12-20% throttle where this happens. Now pull the tail servo in the direction away from the tail case till the tail pitch slider almost fully contacts the tail case.

Then tighten the tail down.

[Bhujang]

Thank you I will try this and see how it goes.

[Bhujang]

So after checking thismis how it was set. There is no binding at all. But on bench testing I am noticing that the servo stops working on extreme use. I then have to add cyclic and pitch to bring it back on board. This would explain the flight experience. Either the as3x for the 130x can't handle the servo or the servo is faulty. I will go back to a linear servo and see if it locks up as well. Maybe the lynx rotary servo is drawing too much current? Or not getting enough? Either way it seems to stop working for a few seconds then start again. It's not binding at either end.

[vtown nick]

The gyro is really odd on these boards. Are you going back to throttle hold or dropping the throttle to 0 when it does this? There is a delay to when the gyros turn off in the time it takes the servos try to counter movement and just sit there at extreme throws.

[Bhujang]

What I'm experiencing now is a hard one time bounce on both cow and cw hard rudder movement.

Can that be taken out with gain on the blue channel,of the gyro setting?

Or is it because I have too much pitch one side over the other?

They look pretty even tbh followed your technique to the T and really set it well this time lol

[Bhujang]

Ok just re read the lynx set up as well. There is zero binding and the servomis about 8mm from the frame. I'm getting really bad wag now gain normal not so bad, 3 clicks up same, 5 clicks up worse. Maybe I should try a negative gain on the tail? Or maybe it's set too far away from the main frame? Dam I used to have this tuned in lovely now I'm back to square one lol. Well at least I have a stock 130x with the linear servos flying great. Still working on my 180 cfx. Finished the TT slipper clutch v3 today servo savers all done, and the cf servo tab savers all done. Remounted esc so the motor doesn't eat it just have to calibrate the cc esc and re check the tx settings and should be ready for a maiden

[Bhujang]

I just don't know where I'm going wrong with this servo now. At this rate I will end up back with a linear on the tail

I've tried the next hole out now and re-adjusted the servo on the boom so that the tail slider has absolutely no binding and 0 and 100% throttle and it it does it wag wag wag. I've played with the tail gains one at a time up to the max and even the negatives but the tail wags like crazy. The bounce on rudder stop was a dream compared to this. So I have gone back to the first hole on the servo horn, reset the tail gains, made sure that the pitch slider doesn't bind at either end of the rudder movements with 0 and 100% throttle and will try again tomorrow when there is some light to test it out lol. If I still have wag there must be something else a miss. I will have to strip it down and check all the bearings for play and that the tail spindle is true as well as feather shaft and main shaft etc. Gears are holding well so it can't be that.

Anyone any ideas? And don't say in it and stick to the 180 cfx lol as I love the 130x

[vtown nick]

With a rotary tail servo I always go down on the gain because it's more responsive than a stock one. I've always gotten some bounce on stops too. Not enough tuning options for tail on the 3n1 so it's best to drop the gain way down. It won't blow out that servo has tons of torque.

[Heliwhisperer]

I have a DS76T on one of my 130s and have not had to adjust any gain settings.
Just stuck it on and flew the sucker.

The only time I ever had any issue with a wag was due to slop in the tail pitch system. Any movement in the slider,lateral movement of the tail case bearings,side movement of the tail shaft in the ''D'' holes of the gears etc.

Maybe check one of these issues?

HW.

[helibus]

Originally Posted by Bhujang

...At this rate I will end up back with a linear on the tail...

Well, give the DS76t a shot before you go that far! I seem to remember threads long ago where some people never got their Lynx servo to work out for them.

Seeing the servo freeze up in bench testing would really concern me. Have you measured your BEC output from the 3-in-1? Maybe if it's a bit low the servo is kicking in and out with any additional variation in voltage.

[Bhujang]

Thanks guys for the inputs felt like a ghost town In here.

Well I will try my last settings today on the lynx servo then I will try a eflite ds76t with thanks to the 180 cfx they come with the correct plug on now too

I will also first try a mechanical check up including new tail boom, check for play in tail shaft with the bearings and replace the c n d for metal gears. Or at least new white plastic ones.

How can I measure the out put of the bec helibec? It's weird as it's sticking at the extremes but zero mechanical binding. Maybe sticking is the wrong word as it's like a huge delay until it will swop to the other input.

If it is the bec what can be done? Is is a replacement job on a chip? Not sure if I have one in spare I remember buying something for the 3 in 1 that burns out a lot but never needing to replace it.

Cheers

Bhu

[Bhujang]

Ok I have it back to just the bounce now. I'd love to get this servo working as it's on but my have to resort to the bigger ds76 one just to see if that is the same. At least the wag is gone and it's flyable.

Does altering the tail gain help reduce the bounce?

[helibus]

Originally Posted by Bhujang

...felt like a ghost town In here.

Yeah, it has been pretty quiet, and it won't be getting any better since fewer and fewer people care about the 130x as time goes on. I typically check the 130x forum daily, even though I haven't done any serious flying with anything for over a year. Across all the forums I monitor, I now tend to post only when I have first-hand experience on a topic and even then, after first waiting a while to see if someone else covers it.

How can I measure the out put of the bec helibec? It's weird as it's sticking at the extremes but zero mechanical binding. Maybe sticking is the wrong word as it's like a huge delay until it will swop to the other input.

If it is the bec what can be done? Is is a replacement job on a chip? Not sure if I have one in spare I remember buying something for the 3 in 1 that burns out a lot but never needing to replace it.

The "holy grail" of info on the 3-in-1 BEC is arguably thread Identify 130x 3 in 1 BEC failure. Servos being slow to respond is one of the symptoms mentioned in the thread.

The BEC is the source of power for the servos, so I used to suggest people tack short wires onto the exposed linear tail servo to monitor the BEC. You don't have that option. You could either tack some wires onto the pads mentioned in the BEC failure thread or tack some wires onto the red & brown wire pads at the top of one of the cyclic servos. I suggest tacking wires on rather than just probing with a meter so that you can better monitor what the BEC output is doing when you move servos around in a bench test. In my case, the output wasn't all that low but I did see it varying quite a bit when I'd manipulate the servos around.

In the 3-in-1 design, the BEC output transistor is easily stressed by a momentary servo wiring short or overcurrent from servo binding, which happens to everyone at some point. Some gurus used to send all of their 3-in-1s to megasmicros for a BEC upgrade as a precaution before they even used them. People have replaced the output transistor themselves, but it isn't exactly trivial. Takes the right combination of tools and soldering experience to do a good job of it, and a few have damaged their 3-in-1 in attempting it. Having a hot air rework station makes a big difference.

[Bhujang]

Ok good news bad news scenario. Good news is I've found the problem. It's mechanical and it's the mesh between the A and B gears. The B gear has play on it. This is the Xtreme frame and I remember it came with shims for this and I added only one at the time and thought sod that when it still had play as it was so hard to do. Ive just stripped it down and thought I had it sorted (trashing the elevator servo in the process, quick solder will fix it but I had a new one for now ) its better than it was but still kicks with a slight play so needs one more shim. I have decided to add the last shim by removing the main gear and shaft this time (A gear as well ) shim the B then put it back together and see if there is any play along the TT with the B gear. Basically it was creating a kick as the B gear slide back n forth as the speed increased. Probably didn't effect the linear servo so left it at that. So I will fix this play and get back with my success story I hope thanks for the info on the Bec. Basically the rudder is staying a long time on full gimbal commands. So if I go full right and then go left it holds right for a while then does the command. Almost like a lag. Could be because I'm not in the air. We shall see...

Cheers

Bhu

[Bhujang]

Thank you all for your patience and help. Another success story my 130x with lynx rotary back to its fully working self. No vibes. No bounce and alls well. New tails and mains to celebrate

Cheers

Bhu

[helibus]

Glad to hear you've taken care of the issues.

Originally Posted by Bhujang

... Basically the rudder is staying a long time on full gimbal commands. So if I go full right and then go left it holds right for a while then does the command. Almost like a lag. Could be because I'm not in the air.

That "I'm not in the air" makes a big difference on the 130x. Sorry - I should have caught on earlier that you were bench testing. Bench testing servo movements on the 130x is tricky. When you move a stick and the 130x doesn't see an attitude correction, it starts tracking an error between what the attitude is and what you asked for. The longer you hold the stick or the farther off center you go, the larger the error gets. This is an error that the 130x continues to think *must* be corrected, even when you return the stick to center or even give opposing stick. There's some limit to the extent of the error, but the recovery can take multiple seconds (or hitting TH, which instantly zeroes out the error).

The best way to test servos on the 130x is to disconnect the motor and power up with the 130x setting on the bench. Apply some throttle to enable the gyro loop in the 3-in-1. Leaving the cyclic and rudder TX sticks at center, slowly move the 130x back and forth about the main shaft. You should see the servos move as the 3-in-1 attempts to correct what it thinks are undesired in-flight attitude changes.

[Bhujang]

I just remembered I do have the upgrade Bec just never got around to installing it. I have a pretty decent solder station so might have a go if it still plays up. Test flight went good. Just need to reset the pitch for some reason as loads of negative pitch and not enough positive. Not sure how that changed so much. Something must have really been out of place

[3D Ambitions]

Good to know you got your 130x flying well.

There are plenty of us still flying our 130x's I have five myself with a ton of spares, so I'll be flying mine for a while to come. Enjoy!

[Bhujang]

Wow 5 that's cool. I'm on 3 with lots of spares must admit I do the love 180 cfx though. So much easier to work on.