Cyclic bounce

[J-S-Q]

I've finally got a few flights in on my TRex 500EFL Pro with the GT5. Maidened it with all settings at default and it flew reasonably well, but felt a little bit soft and not quite as locked in as I would like. I followed Swalko's tuning guide and after three packs of adjusting settings it now feels really great. (I have a Beast X sitting on the shelf and don't feel the urge to swap it for the GT5). The only thing I still need to tune out is an elevator/aileron bounce on hard cyclic stops. I tried various settings for D-Sense but didn't manage to get rid of the bounce. Possibly I missed the sweet spot because I was changing it by reasonably large amounts (about 10 at a time) but I tried quite a few values from about 20 up to about 70. Anyone got any ideas what I should try?

Apart from that I really love the way it flies. Very fast cyclic rates (which may also be to do with the high headspeed of the 500EFL), very stable and a great feel to the tail.

[mrultralite]

Are you using a full Rx as a failsafe?

[NitroAl]

Turn down IDStick to 90. What is your feed forward set at?

[swalko]

I've finally got a few flights in on my TRex 500EFL Pro with the GT5. Maidened it with all settings at default and it flew reasonably well, but felt a little bit soft and not quite as locked in as I would like. I followed Swalko's tuning guide and after three packs of adjusting settings it now feels really great. (I have a Beast X sitting on the shelf and don't feel the urge to swap it for the GT5). The only thing I still need to tune out is an elevator/aileron bounce on hard cyclic stops. I tried various settings for D-Sense but didn't manage to get rid of the bounce. Possibly I missed the sweet spot because I was changing it by reasonably large amounts (about 10 at a time) but I tried quite a few values from about 20 up to about 70. Anyone got any ideas what I should try?

Apart from that I really love the way it flies. Very fast cyclic rates (which may also be to do with the high headspeed of the 500EFL), very stable and a great feel to the tail.

D-Sense is very sensitive, 10 points step is too big. Use 5 points steps for fast tweaking, 1 points steps for precise tweaking. P/I/D-Sense needs to be in correct ratio. What is your G-T5 settings? Wobble may be caused/eliminated too by feed forward and ID-Stick.

[J-S-Q]

Here are the settings that I am running:

P 120
I 100
I-D-stick 100
D-sense 50 (various values tried)
Feed Forward 85
I-lim 18
Hover stability 5

It was quite windy when I did my first tuning flights so maybe I ended up making P and I higher than they really needed to be as it was harder to tell when I got to the point of flips/rolls being really nice and consistent.

I think maybe I will experiment with lowering I-D-stick a little bit and then try changing D-Sense by smaller amounts and see if that helps. I will also probably try lowering the hover stability back to the default 3 (I initially raised it because the heli was a bit sloppy/unstable but this was before I raised P and I which cured that problem all together. No idea whether this will have any effect on the bounce issue though.)

[swalko]

Here are the settings that I am running:

P 120
I 100
I-D-stick 100
D-sense 50 (various values tried)
Feed Forward 85
I-lim 18
Hover stability 5

It was quite windy when I did my first tuning flights so maybe I ended up making P and I higher than they really needed to be as it was harder to tell when I got to the point of flips/rolls being really nice and consistent.

I think maybe I will experiment with lowering I-D-stick a little bit and then try changing D-Sense by smaller amounts and see if that helps. I will also probably try lowering the hover stability back to the default 3 (I initially raised it because the heli was a bit sloppy/unstable but this was before I raised P and I which cured that problem all together. No idea whether this will have any effect on the bounce issue though.)

P/I/D-Sense needs to be in correct ratio. I stated this in last update of G-T5 tweaking guide. On my TDR this ratio is 1:1:0.25 (100/100/25). Very small differences out of this ratio and my TDR fly bad. Based on my experience and your posts my suggestion for you:

P/I/D-Sense: 100/83/25
Hover: 4
I-D-Stick: 100

If your heli will fly good with my settings, but controls feels little undefined, raise your total gain in TX by 20%.

Try it and report.

[J-S-Q]

P/I/D-Sense needs to be in correct ratio. I stated this in last update of G-T5 tweaking guide. On my TDR this ratio is 1:1:0.25 (100/100/25). Very small differences out of this ratio and my TDR fly bad. Based on my experience and your posts my suggestion for you:

P/I/D-Sense: 100/83/25
Hover: 4
I-D-Stick: 100

If your heli will fly good with my settings, but controls feels little undefined, raise your total gain in TX by 20%.

Try it and report.

Ok thanks, I will try that and report (although it may be a couple of weeks before I can get out and fly again). I have the gain at 100% in my tx at the moment so I guess the GT5 is capable of having gains higher than 100%?

[swalko]

Yes, up to 149. I use 115/100/85 total gain.

[growmaster4]

Loaded up those numbers on my 500esp,we will see how it.goes,it was feeling a bit loose in the wind yesterday,hope they work well

[J-S-Q]

I tried the new settings today and it didn't cure the cyclic bounce problem unfortunately. It's kind of hard to say because it's about 3 weeks since I flew this heli but I think possibly it flew slightly better with my previous settings (not due to the bounce, but it maybe just had a generally more consistent and controlled feel to rolls/flips etc.). The cyclic bounce is only on elevator by the way, not on aileron.

So I guess it's back to the drawing board. :)

[growmaster4]

Maybe you have a issue with your unit,I had to send mine back for a elevator drift that wouldn't go away.

[J-S-Q]

Maybe you have a issue with your unit,I had to send mine back for a elevator drift that wouldn't go away.

What settings are you using on your 500ESP and how do you find it?

[growmaster4]

I used the settings posted here,the unit just started drifting on ele.they use double sided tape inside the case to secure the unit,could have came loose.

[swalko]

I used the settings posted here,the unit just started drifting on ele.they use double sided tape inside the case to secure the unit,could have came loose.

Have you some photos of the unit inside?

[J-S-Q]

I used the settings posted here,the unit just started drifting on ele.they use double sided tape inside the case to secure the unit,could have came loose.

So have you now got a replacement unit that is working well? What kind of flying are you doing? My flight style is sport/aerobatics and I can quite happily fly circuits, some loops etc and see no sign of the bounce and it does fly very well. It's when the heli is in a hover and I give a deliberately hard jab to full elevator and then go straight back to neutral, that the heli will wobble/bounce.

[swalko]

So have you now got a replacement unit that is working well? What kind of flying are you doing? My flight style is sport/aerobatics and I can quite happily fly circuits, some loops etc and see no sign of the bounce and it does fly very well. It's when the heli is in a hover and I give a deliberately hard jab to full elevator and then go straight back to neutral, that the heli will wobble/bounce.

If you fly gentle all is fine?

[J-S-Q]

If you fly gentle all is fine?

Certainly for just flying circuits, it flies perfectly. It flips/rolls nicely it's just on quite hard stops from an elevator flip. On tic tocs it is fine as well.

I didn't get this bounce at all though when I had a Beast X on my 500ESP or 700N and whilst I can happily fly like this, I would still like to get rid of the bounce.

[swalko]

Certainly for just flying circuits, it flies perfectly. It flips/rolls nicely it's just on quite hard stops from an elevator flip. On tic tocs it is fine as well.

I didn't get this bounce at all though when I had a Beast X on my 500ESP or 700N and whilst I can happily fly like this, I would still like to get rid of the bounce.

How much cyclic throw you get in menu? This may be caused by low cyclic gain (cyclic throw, servo travels, total gain, ... ). I had similar problem too. My TDR flown big aerobatics nice and straight, hand off inverted hover without any issues, but on hard rate changes i had cyclic wobble and controls was little undefined ... i needed to be very gentle on stops. I raised P/I/D-Sense from 60/60/15 to 100/100/25 and it was much better, but i mean that i still need higher gains (120/120/30 - will test soon).

[J-S-Q]

How much cyclic throw you get in menu? This may be cause by low cyclic gain (cyclic throw, servo travels, total gain, ... ). I had similar problem too. My TDR flown big aerobatics nice and straight, hand off inverted hover without any issues, but on hard rate changes i had cyclic wobble and controls was little undefined ... i needed to be very gentle on stops. I raised P/I/D-Sense from 60/60/15 to 100/100/25 and it was much better, but i mean that i still need higher gains (120/120/30 - will test soon).

I will check the cyclic throw because I can't remember how much I set.

[swalko]

I will check the cyclic throw because I can't remember how much I set.

Did you tried to raise total gain (120% or more) with suggested settings?

[NitroAl]

The instructions recommend lower ID-Stick for smaller heli's to avoid cyclic bounce on elevator so I would be inclined to follow Swalco's guidance to get it as good as you can and then start working on ID-Stick!

[J-S-Q]

Yes I did try raising it to 120% but it still didn't cure the problem.

[J-S-Q]

The instructions recommend lower ID-Stick for smaller heli's to avoid cyclic bounce on elevator so I would be inclined to follow Swalco's guidance to get it as good as you can and then start working on ID-Stick!

Yes, you are right. I just had a look at the manual and it says lowering ID-Stick to 60-80% can help eliminate cyclic bounce on smaller helis. I have not experimented at all with this parameter yet so next time I'm out, I will try lowering it and see what happens.

[swalko]

Yes I did try raising it to 120% but it still didn't cure the problem.

Then i recommend you to play with I-D Stick. I do not have currently own experience with I-D Stick, but Tail Stick Dynamic was for me the only one way to eliminate tail overshooting on stops (similar to cyclic bounce).

[J-S-Q]

How much cyclic throw you get in menu?

I just checked my cyclic throw (it doesn't matter which menu I am in does it? Just as long as I am in any of the menus?). In menu, I have +/-9.7 degrees cyclic at full stick.