Cant get the tail rock solid

[EtheAv8r]

I currently have a CSM 420 – Futaba S9257 for the tail on my Outrage G5 (1700KV motor, stock 11t pinion and tail drive) – but I cannot get it rock solid. The tail is carefully set-up, no play, very free and I have replaced the poor (IMHO) bent wire pushrod for a 3mm straight carbon pushrod –-stiffer, bind free, direct and half the weight. The Gyro is carefully set up and calibrated, endpoints set etc.

I am just a gentle sports flyer and very much at the beginner end of flying skills – no hard 3D but I cannot get the tail rock solid. I have been from 50% to 100% EPA on the HH gain switch which goes from wafty to waggy (not regular but intermittent), and cannot stop the tail pushing out and then back when making collective changes. There is no ‘sweet spot'. Right Piro stops are good, left bounce quite hard.

I have been trying to call CSM Tech Support for two weeks not – phone never rings as if busy all the time – or no line.

I am thinking maybe of changing the Gyro for either CY Mini G or a Spartan DS760 (Sport?). Am I simply doing something wrong, or would a gyro change not be a waste of money?

[Paulice]

Is your head speed to slow?

[moyesboy]

This gyro should work fine - but I haven't used this particular one myself.
As posted, if the head speed is too slow then the tail can't really do its job. The main blade pitch requires a lot of torque to push it and at the same time the tail is spinning slower than it should be.

Check you have 4 degrees or less pitch at the hover point. If you have more than that then the head speed is too low. It will also fly all wobbly and mushy if you are trying to work with less than 2000 rpm. These little helis like head speed.

Your stops are not behaving equally. - Maybe you have started with the linkage not near enough the middle. Try to start with the tail slider in the middle of its movement when the servo is in the middle. Plug the servo direct to the rudder channel and set that in the middle with no trim. Then introduce the gyro and set the end points to avoid binding.

Probably they are on holiday at CSM or something - they are usually very good on the help line.

My 450 is flying well with a CSM720.

[EtheAv8r]

I can experiment with higher headspeed, but the G5 is designed to operate at much lower headspeeds than the typical 450 size helicopter 2700 is max for exptream 3D, and the model flys great, not wobbly or mushy, sits in the hover and moves in forward and backward flight rock solid (apart from tail moving occasionally) and is very responsive.

Not sure what the actual headspeed is - thinking of getting a gismo to measure it (MA-XT or Sky-Tach).

[moyesboy]

01457 854680 rings normally for me (but of course its after hours now).
Yuo can try emailing tech@csm-ltd.co.uk as well

On the servo you need a very short servo arm. If you have it too long you end up reducing the throw and losing resolution with the gyro, and the servo ends up without enough power. you should have about 90 degrees total travel on the servo. There is probably some advice on the linkage setup at www.outrage-tuning.com.

Check for something mechanical like a slack belt jumping teeth. The belt stretches over the first 10 flights or so then stabilises (well, the align one does).

[Ashley Davis]

from what I remember you can't configure the CSM 420 at all, which makes setup on very small heli's quite critical to servo horn length. The 420 whilst a good gyro on a larger heli can sometime struggle with the smaller ones due to the inability to tune it.

[EtheAv8r]

01457 854680 rings normally for me (but of course its after hours now).
Yuo can try emailing tech@csm-ltd.co.uk as well

On the servo you need a very short servo arm. If you have it too long you end up reducing the throw and losing resolution with the gyro, and the servo ends up without enough power. you should have about 90 degrees total travel on the servo. There is probably some advice on the linkage setup at www.outrage-tuning.com.

Check for something mechanical like a slack belt jumping teeth. The belt stretches over the first 10 flights or so then stabilises (well, the align one does).

That is the number I have been calling - perminently busy. CSM setup guide stated usually too short a servo arm is the problem, rarely too long. The CSM and Spartan and CY MiniG setup instructions all warn agaist using a servo arm that is too short and recommend 15-20mm - mine was originally at 8.5mm in line with G5 guidance. I have since fitted a longer arm at 11mm (which fits the CSM guidance of full throw plugged direct to the Rx of 90% and 110% ATV) and was planning trying an even longer one next and the CSM instructions could be interpreted as requiring a max og 90% for this arm lenght test.

Belt not slack or slipping. I have read every thread on outrage tuning - the G5 section is not very active.

from what I remember you can't configure the CSM 420 at all, which makes setup on very small heli's quite critical to servo horn length. The 420 whilst a good gyro on a larger heli can sometime struggle with the smaller ones due to the inability to tune it.

Not being familiar with high end gyros I am not sure what these other parameters would be. I was delighted with the accurate end-point adjustment from the CSM420 which the built-in gyro on the Hellicommand does not have. I originally was going to buy the CSM420e which is apparently faster and more suited to small electric helicopters - but was persuaded by Inwoods the the 430e was impossible to set-up and advised to get the 420. Maybe having CSM reflash it to 430e might be a good idea.

[whirlybird]

Hi
Funny that. I phoned CSM twice last week, no problem and very helpful, as always.
Perhaps they are having phone problems. Keep trying.
Cheers
Jeff

[Made2Fade]

What throttle curves are you using? Im guessing its that coupled with servo horn length.

[SRH990]

I'd also guess it's linked to servo horn length, it sounds as if you are too far out, as previous posts but I do have one thought to add, have you mounted the gyro with the thick black squishy pads that CSM provide? If so just use a single layer of 3mm tape, the stuff CSM supply is way to thick for virtually every situation and definitely isn't needed on electric helis.

[EtheAv8r]

Headspeed is not the problem – I have increased it but to no avail. I took the machine in to Inwoods on Saturday, they were very helpful. Checked and confirmed the tail is smooth and free and binding is not the issue, and made a number of good suggestions to try before buying a new Gyro (they showed me the new Futaba GY 520, it is so small and dinky – I nearly bought one, but they advised I hold off replacing the CSM 420 until I have experimented further and talked to CSM about possible re-flashing my 420.

The gyro is mounted on the CSM thick foam…. And I bough an extra box of spares! This 3mm tape – what make is it?

[SRH990]

I'm using a white double sided tape sold as servo tape which is around 3mm thick, you could also use a 401 gyro pad cut to size.

[Nick B]

They sell that 3mm double sided white tape at focus.I have used it on several gyros with no issues.

[EtheAv8r]

Thanks chaps - I will try that!