Trex 600 low headspeed help for beginner

[blackmagicRC]

Hey guys!

I bought a used Trex 600 recently. It came with 2 12s lipo battery packs. A 6s and a 2s connected in series. 5800mah 30C. I couldn't figure out how to charge batteries wired up like this, so I bought a 6s 5000mah pack to use instead of the ones that came with the heli. Well, I'm experiencing some nodding up and down in the tail, and I'm pretty sure that means my head speed is too low. Someone suggested putting a larger pinion on the motor to solve my problem. The one on there now has 15 teeth. I've found 16 and 17 tooth pinions online. My problem is, I'm not sure what size shaft is on the motor itself and I know if I order them and they're not the right size then I still have a problem. The motor is a Turnigy 600 4030 880kv if that helps.

So basically I'd like to know if the larger pinion will solve my problem, or if I need to do something else to get the head speed up.

Thanks again guys! Bear with me, I havnt been at this for very long. I've been flying 450s. This is my first 600. Other than the nodding, it's a very stable bird. I feel I will progress much faster once I get it straightened out.

[WildBird22]

Tail bobing up and down usually means HeadSpeed to Low or Head Dampeners are worn out. What is your throttle curve set at?

[blackmagicRC]

Currently is 0,50,80,90,100. I also played with flat curves like 0,80,80,80,80 and 0,90,90,90,90. No help

[blackmagicRC]

I figured the smaller battery may have had something to do with it. The packs it came with are 5800mah. The ones I'm using are only 5000

[WildBird22]

I use a single 5000mah battery. A couple of things to check:

1. ESC Throttle End Points - Make sure your ESC is set for 100% at full throttle and 0% at low throttle.

2. What size is the ESC?

3 Are you scale flying or 3D?

[kento]

I thought the turnigy 600 only supported up to 8s?

[blackmagicRC]

Originally Posted by kento

I thought the turnigy 600 only supported up to 8s?

I meant 8s. That was my mistake. Lol. Apparently 6s+2s=12s these days!!! Lol

[blackmagicRC]

Originally Posted by WildBird22

I use a single 5000mah battery. A couple of things to check:

1. ESC Throttle End Points - Make sure your ESC is set for 100% at full throttle and 0% at low throttle.

2. What size is the ESC?

3 Are you scale flying or 3D?

The ESC is 100 amp. Right now just basic FF and hovering. I havnt been flying long enough to do 3D

[blackmagicRC]

Im hoping that just throwing a 17t pinion on there will give me the head speed i need. I just want to stop the nod. Right now i don't really care if its enough for extreme 3D or not. Once i get to that point i will probably just make this bird a scale build and get a 600 or 700 nitro for 3D

[WildBird22]

Before you spend a bunch of money, Make sure your blades are balanced. If that checks out ok, check the dampeners behind the blade grips....they don't last forever, and they are not expensive. BLACK Dampeners are Hard, and GRAY Dampeners are Soft.
Also make sure the motor is not worn out. If the motor is a Turnigy Typhoon 600H 1100Kv (Black Motor), that a 6s Motor. Running 8s can damage it and shorten its life.

[blackmagicRC]

Originally Posted by WildBird22

Before you spend a bunch of money, Make sure your blades are balanced. If that checks out ok, check the dampeners behind the blade grips....they don't last forever, and they are not expensive. BLACK Dampeners are Hard, and GRAY Dampeners are Soft.
Also make sure the motor is not worn out. If the motor is a Turnigy Typhoon 600H 1100Kv (Black Motor), that a 6s Motor. Running 8s can damage it and shorten its life.

Thanks. I will check the dampeners. The heli only had about 20 flights or so on it when i got it, so i don't think they're very worn. Never hurts to check though! The motor is the 880kv version (red). I don't know if that makes a difference or not.

[Keyrigger]

Judging by the kv of the motor, that heli was setup to run on 8s so your headspeed on 6s is going to be a bit low. If you are flying around and not expecting to do anything wild with it, getting a pinion a bit larger will help bring the rpm up to where the bobbing of the tail will start to diminish. Getting a set of very soft dampeners will help things a lot. Align makes two soft dampener sets, the grey ones as mentioned, and the red ones, which came out for the F3C heli's. If you change to those, you will also see a drop (should be none after the change) in the bobbing of the tail.

What I don't understand are the 12s batteries as they would bring the headspeed up with the existing motor to a level that could be approaching dangerous levels. However, just leave them aside and concentrate on the 6s setup for now. I am running an 890kv motor in a scale Jet Ranger at 1400 to 1550rpm with the grey dampeners on a governored system and it runs smooth as silk. This is on a 550 chassis with a 16t pinion and 170t maingear. On a 600, it should work out to be about the same except for the larger rotor, which will slow it down a bit.

Lastly, you didn't mention whether the electronics included a 3 axis gyro? If it is so equipped, you could lower the elevator gain down a bit and that may help things a lot. But only if so equipped. A standard tail gyro will not have any effect (to the best of my knowledge) on the bobbing up and down of a tail boom in flight/hover. Hope this helps. Take care.

Don

[blackmagicRC]

Originally Posted by Keyrigger

Judging by the kv of the motor, that heli was setup to run on 8s so your headspeed on 6s is going to be a bit low. If you are flying around and not expecting to do anything wild with it, getting a pinion a bit larger will help bring the rpm up to where the bobbing of the tail will start to diminish. Getting a set of very soft dampeners will help things a lot. Align makes two soft dampener sets, the grey ones as mentioned, and the red ones, which came out for the F3C heli's. If you change to those, you will also see a drop (should be none after the change) in the bobbing of the tail.

What I don't understand are the 12s batteries as they would bring the headspeed up with the existing motor to a level that could be approaching dangerous levels. However, just leave them aside and concentrate on the 6s setup for now. I am running an 890kv motor in a scale Jet Ranger at 1400 to 1550rpm with the grey dampeners on a governored system and it runs smooth as silk. This is on a 550 chassis with a 16t pinion and 170t maingear. On a 600, it should work out to be about the same except for the larger rotor, which will slow it down a bit.

Lastly, you didn't mention whether the electronics included a 3 axis gyro? If it is so equipped, you could lower the elevator gain down a bit and that may help things a lot. But only if so equipped. A standard tail gyro will not have any effect (to the best of my knowledge) on the bobbing up and down of a tail boom in flight/hover. Hope this helps. Take care.

Don

Thanks a lot Don!!!

[sherman89]

If I read your thread correctly you have 6S and a 2S pak which if run in series it would produce 8S which is what is needed to drive the 880KV motor. You can go to a bigger pinion and increase the HS with a 6S pak or putt the 6S and the 2S in series and drive the motor the way it was designed to be driven giving you the HS 1800+----your bobbing will go away the heli will fly. If you go to readyheli.com and use the HS calculator you will find what you will need for a pinion to work with the 6S pak and get your HS up to at least 1800----the 600 really likes 2000+ but if hovering is what you are doing then 1800 will work and give you longer flight times.

[blackmagicRC]

Thank you! I will check that out!

[sherman89]

Your 880 kv motor was designed around the 8S power---it will run on 6 S but not quite as well as 8S because of your volts to amps relationship----a more efficient motor for the 6S will be a 1000-1200 range motor. I used to run a scorpion 890kv on 8S (6S+2S=8S) but have gone back to the 6S-5000 to keep my power paks in line as I fly a TSA Infusion 700-E and want to keep my pak inventory the same. The 8S power is more efficient over the 6S with the 880kv motor because the voltage is higher needing less amps to do the same work and where you see the difference is the battery temps are lower with the 8S over the 6S. Excessive heat kills li-po's so the lower the temp the longer the pak will last. Do not exceed 135F.

[sherman89]

KV X volts=rpm.