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HelicopterMain Discussion › Swash levelling tool size
03-02-2018 04:19 PM  82 days agoPost 21
Richardmid1

rrProfessor

Leeds, England

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I used to adjust the swash links for no drift in a hover, usually right link shorter and left link longer by 1 turn does it but then I realized that is screws up inverted hover so I just set it level now. That's flybarred though, I just hit it with a hammer for FBL because it doesn't matter so much!

60% of the time, it works every time!

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03-02-2018 04:26 PM  82 days agoPost 22
dkshema

rrMaster

Cedar Rapids, IA

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They make horrible vacation spots.

-----
Dave

* Making the World Better -- One Helicopter at a time! *

Team Heliproz

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03-02-2018 05:20 PM  81 days agoPost 23
Flyin for Jesus

rrVeteran

Troy, IL. 62294

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Just doing some thinking...
So you prefectly level your swash ( lets just assume absolute perfection on all of this )
Then you hover the heli with it perfectly level, then you'll have some drift from the tail rotor.
But if you simply tilt the heli ( say 1/4 degree ) and that offsets for the translation from the tail, then you have a level swash ( to the mainshaft ) and the heli will hover perfectly.
I guess the way I see it... and heli with a self-level feature would require the swash adjustment so it will hover stationary ( not counting wind ).
I say this because I've had flybar helis out of trim where its level, drifts( say to the left ) so I overcorrect to stop the drift and also go back the where it started stationary, and without touching the sticks, it travels back right then stops then drifts left again... so I continually have to give right inputs.
With setting a FBL heli with a level swash, I have never had this.
It always stays in the position I have left it in. So it really depends on me to get it to lean into the transational tendency and stay put. It could be 1/10 degree or maybe 1/2 degree but either way, once I position the heli to counteract that... it just stays put, no adjustment ever to the swash other then the initial setup making it level.

Just my thoughts and observations...

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03-02-2018 07:50 PM  81 days agoPost 24
ICUR1-2

rrElite Veteran

Ottawa, Ontario

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dkshema
To sense and correct for drift, your FBL controller would also need to incorporate accelerometers as well as gyros.
All modern FBL units have accelerometers now. Those with rescue anyway.

spending time, paying attention

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03-02-2018 08:32 PM  81 days agoPost 25
ticedoff8

rrKey Veteran

Morgan Hill, CA. USA

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Accelerometers do not affect (good or bad) drift in a hover.
Assuming the gyro is in a hover or simply sitting on the ground, the accelerometers let the gyro know where "down" is.
Assuming the gyro (heli) is "level", the X & Y accelerometers sense 0g and the Z accelerometer senses 1g (gravity).
If the heli is tilted on the ground (like a Goblin), the the X shows 0.02g, Y shows 0g and the Z shows 99.08g.

You may think that the drift is detected by the accelerometers.
But the drift is such a slow acceleration (or none), that the accelerometers are not sensitive enough to detect it or the designers cannot spare any CPU cycles to deal with it.

Gyros like the MSH brand (iKON and Brain) will use the accelerometers for "Rescue" or "Auto Level".
They will Rescue the heli to an upright position (because they help the gyro know where "down" is), but will not "Rescue" to a stable (stationary) hover.
In the MSH gyros, "Rescue" will flip the heli "upright" and apply a little positive collective. Then, after a set-time, it will release control back to the transmitter and act more like "Auto Level".
"Auto Level" will flip the heli upright and keep it within a 30-deg cyclic angle. You can drive the heli around in "Auto Level", but not in "Rescue".

The only way to "cancel" drift is GPS.

Normal stance of a perfectly balanced heli in a stable hover is slightly tilted on the Y axis but the rotor disk needs to be, more or less, "level". The "less" is when the rotor disk is slightly correcting for tail rotor anti-torque thrust.
By adjusting the swash links, you are basically canceling out the correction the gyro is applying based on what it is sensing due to the tilt.
This is more about the FBL gyro's gyros and not the accelerometers. A fybar is a gyro.

But, drift also occurs due to a tilt associated with a nose-heavy / tail-heavy heli. Or the nitro heli with a big pipe sticking out one side with no counter-balance on the other side (like the 2oz header tank).

The software developers for MSH recommend zeroing out the drift in a hover. And it is typically done by some of the most awesome 3D /smack heli pilots as a routine part of setting up the heli.

I know of at least 1 incredible 3D pilot that does not use a swash leveler or zip-tie at all. They eye-ball it, then adjust the links as necessary to cancel out the drift.
That's not me.
I use the swash leveler tool and then adjust linkages

Believe 1/2 of what you see and none of what you hear.
Fake News will be the downfall of our Republic!

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03-05-2018 03:12 AM  79 days agoPost 26
Jamovich

rrVeteran

Bangalore, India

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Richardmid1
Out of stock but I use this one: https://www.fast-lad.co.uk/store/he...22-p-26650.html
How do you actually use this? I have one but the magnet is not strong enough to stop all play. If the swashplate is slighlty off the magnetic collar will also be slightly off...therefore it is not an effective reference

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03-11-2018 07:24 PM  72 days agoPost 27
spaceman spiff

rrKey Veteran

Tucson

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,,

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03-12-2018 11:42 AM  72 days agoPost 28
Richardmid1

rrProfessor

Leeds, England

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Jamovich
Richardmid1
Out of stock but I use this one: https://www.fast-lad.co.uk/store/he...22-p-26650.html
How do you actually use this? I have one but the magnet is not strong enough to stop all play. If the swashplate is slighlty off the magnetic collar will also be slightly off...therefore it is not an effective reference
It is not designed to go hard against the swash plate. Leave a very slight gap and adjust so the gap is the same all the way around. Also it won't work on main shafts smaller than 8mm.

60% of the time, it works every time!

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03-12-2018 11:47 AM  72 days agoPost 29
Richardmid1

rrProfessor

Leeds, England

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ticedoff8
I know of at least 1 incredible 3D pilot that does not use a swash leveler or zip-tie at all. They eye-ball it, then adjust the links as necessary to cancel out the drift.
I do this on smaller helis but I don't cancel out the drift in a hover as I very rarely hover!... well, not upright anyway!

60% of the time, it works every time!

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03-12-2018 05:53 PM  72 days agoPost 30
ticedoff8

rrKey Veteran

Morgan Hill, CA. USA

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Richardmid1
I do this on smaller helis but I don't cancel out the drift in a hover as I very rarely hover!... well, not upright anyway!
Then, without realizing it, you are fighting the FBL gyro for the whole flight.

Believe 1/2 of what you see and none of what you hear.
Fake News will be the downfall of our Republic!

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03-13-2018 11:17 PM  70 days agoPost 31
Richardmid1

rrProfessor

Leeds, England

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Sorry I was talking about flybarred. FBL has way less drift even with an eye balled level swash. Swash doesn't need to be that level for FBL in the same way the tail doesn't need to be setup drift free in rate mode for it to work well in HH. The gyro doesn't care where it needs to put the servo to stop drift.

60% of the time, it works every time!

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03-14-2018 07:00 PM  69 days agoPost 32
Car6on14

rrNovice

Durham, NC USA

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ticedoff8
That's an interesting option.

I think they are in-stock at the manufacturer

At $12, I might buy one - it seems like a universal solution (8mm to 15m
I agree for $12 its worth a try, anyone on here have one?

Spektrum Dx9

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HelicopterMain Discussion › Swash levelling tool size
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