I made the changes Tomas suggested and have attached the file. I will try it out as soon as weather and schedule permit.
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File comment: spirit pro settings on velos 880
velos8806-8-16.4ds [255 Bytes]
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| Velos 880 tail oscillation https://www.spirit-system.com/phpBB3/viewtopic.php?f=20&t=1472 |
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| Author: | mb-1953 [ Wed 08. Jun 2016 18:24:56 ] |
| Post subject: | Velos 880 tail oscillation |
I have a problem with tail oscillation on a velos 880 in forward flight. I am using the governor with a hobbywing rpm sensor, Castle Edge 160HV esc and an 850mx motor (there are 2 of them receiving the same signal from my spirit pro.) The tail servo is an Align BL850H which has a motion speed of .030sec/60 degrees. My initial governor settings were min 900, max 2000, frequency 200, spool up rate fast, spoolup ramp 120us, gov response 5, Holding performance 6. My pirouette consistency was set at 165. With these settings the oscillation was pretty bad. I changed the following settings: max from 2000 to 1930, frequency from 200 to 333, Governor response from 5 to 8, Pirouette consistency from 165 to 155. I also lowered the rudder common gain from 1.40 to 1.30. The oscillation improved quite a bit but is still there. From the sound of the heli flying there is still an inconsistency in the head speed when doing maneuvers. I have checked the tail linkage with the rotor at speed and it is smooth. I am afraid to lower the pirouette consistency any further and am unsure what to do next. Any suggestions from the experts?? |
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| Author: | ZeXx86 [ Wed 08. Jun 2016 18:41:31 ] |
| Post subject: | Re: Velos 880 tail oscillation |
Hi, regarding governor, throttle range min and max should be configured and your ESC calibrated to these values. Then you shouldn't change it anymore. Else you will not get full power if it is lower than programmed max value in the ESC. I also recommend to lower holding performance - it is quite high. I recommend to set it to value 4 for tests. Regarding tail oscillations, what value of Rudder Delay do you have configured? This is important, because if it is too high you will get tail oscillations in fast forward flight. For your servo value of 0 can be used. Higher values will cause oscillations. Do you use any revomix? Pirouette Consistency can be configured to 170. How the tail is holding now? Could you share your settings here? Just attach profile file here. This can help a lot. |
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| Author: | sacha [ Wed 08. Jun 2016 21:00:33 ] |
| Post subject: | Re: Velos 880 tail oscillation |
I have the same problem. Slow tail oscillation even on hovering. For testing, i disabled the gov on the spirit and used "fixed wing" mode on the ESCs (No gov on the esc too). So we have no gov that is envolved. Head speed 1200 - 1500. The oscillation is still there. Regardless of the "rouder delay" (Tried 0-15) settings or the "rouder gain" (tried 50-100%)setting. |
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| Author: | mb-1953 [ Thu 09. Jun 2016 0:19:03 ] | ||
| Post subject: | Re: Velos 880 tail oscillation | ||
I made the changes Tomas suggested and have attached the file. I will try it out as soon as weather and schedule permit.
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| Author: | ZeXx86 [ Thu 09. Jun 2016 7:24:37 ] |
| Post subject: | Re: Velos 880 tail oscillation |
In this case I highly recommend to verify, if the mechanics is really smooth. Especially on this big helicopter, it is important that it is super smooth in each ball linkage and in any point. If there is slow tail wag during hovering without governor, than it is in 95% caused by something in the mechanics - usually just too tight ball joints. With a ball rimmer, everything can be fixed and performance improved overall a lot. But this apply to each heli, but some kits are more prone to this issue. Some manufacturers are taking care about this, some not. Without a ball rimmer it might take months - years to be really smooth. This can also solve fast tail oscillations/poor performance. But this is just idea what to verify. |
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| Author: | mb-1953 [ Thu 09. Jun 2016 11:50:21 ] |
| Post subject: | Re: Velos 880 tail oscillation |
Tomas, I have no oscillation in hover, that was Sacha's problem. I have gone over the mechanical's several times. I am curious how to calibrate the esc value for full throttle. My 2 idle up settings are 1800 and 1950. I have verified both of these with a tach in hover. |
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| Author: | ZeXx86 [ Thu 09. Jun 2016 17:11:31 ] |
| Post subject: | Re: Velos 880 tail oscillation |
OK. If high values are configured not precisely, it will not cause that your target head speed will be off. It will cause that governor will be unable to reach max. performance or will work improperly. You can find guide from Adrian regarding Castle calibration here on the forum. But governor is very likely not reason for oscillations. I have just found that the throttle speed is configured to 333Hz which is too high for Castle ESC. I recommend to set it at 120Hz at least for now. Other settings are looking good now. |
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| Author: | Adrian [ Thu 09. Jun 2016 19:02:29 ] |
| Post subject: | Re: Velos 880 tail oscillation |
I use 200Hz on both CC edges. 200A and 160A HV. And I use rpm out from Edge. CC Edge guide Tomas mentioned: viewtopic.php?f=17&t=1364 Doing tail tuning, I discoverd, first doing gov tuning is critical. So make sure your rpm is stable, in hoover, doing pitch input like tic toc (gov responce) and adding load doing loops (holding) you will hear if rpm drops or rises or oszillates. Once you got stable rpm, start to look into tail tuning. Rudder tuning guide from tomas: http://www.spirit-system.com/phpBB3/vie ... f=20&t=378 |
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| Author: | sacha [ Thu 09. Jun 2016 20:27:28 ] |
| Post subject: | Re: Velos 880 tail oscillation |
Hi Tomas Thanks for your answer. I have to investigate the mechanics. English is not my native language. What is a "Ball rimmer" ? Sacha |
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| Author: | mb-1953 [ Fri 10. Jun 2016 20:25:14 ] |
| Post subject: | Re: Velos 880 tail oscillation |
I just got back from the field. With the initial settings given in the last post, I had to lower the gyro gain in my dx-9 to 27.0 (was 40) and the oscillation almost stopped. The next flight I was going to try 25.o but there was a tail wag in hover. It remained no matter where I set the gyro gain. I have already removed the tail linkage from the servo and moved it from side to side at 1950 rpm. There is no binding there. Any ideas where to go from here? |
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